| 11. |
- Fleiss, Bobbi, et al.
(author)
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The Anti-Inflammatory Effects of the Small Molecule Pifithrin-µ on BV2 Microglia.
- 2015
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In: Developmental neuroscience. - : S. Karger AG. - 1421-9859 .- 0378-5866. ; 37:(4-5), s. 363-75
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Journal article (peer-reviewed)abstract
- Neonatal encephalopathy (NE) is a leading cause of childhood death and disability in term infants. Treatment options for perinatal brain injury are limited and developing therapies that target multiple pathways within the pathophysiology of NE are of great interest. Pifithrin-µ (PFT-µ) is a drug with striking neuroprotective abilities in a preclinical model of hypoxia-ischemia (HI)-induced NE wherein cell death is a substantial cause of injury. Work from neurons and tumor cells reports that PFT-µ is able to inhibit p53 binding to the mitochondria, heat shock protein (HSP)-70 substrate binding and activation of the NF-kB pathway. The purpose of this study is to understand whether the neuroprotective effects of PFT-µ also include direct effects on microglia. We utilized the microglial cell line, BV2, and we studied the dose-dependent effect of PFT-µ on M1-like and M2-like phenotype using qRT-PCR and Western blotting, including the requirement for the presence of p53 or HSP-70 in these effects. We also assessed phagocytosis and the effects of PFT-µ on genes within metabolic pathways related to phenotype. We noted that PFT-µ robustly reduced the M1-like (lipopolysaccharide, LPS-induced) BV2 response, spared the LPS-induced phagocytic ability of BV2 and had no effect on the genes related to metabolism and that effects on phenotype were partially dependent on the presence of HSP-70 but not p53. This study demonstrates that the neuroprotective effects of PFT-µ in HI-induced NE may include an anti-inflammatory effect on microglia and adds to the evidence that this drug might be of clinical interest for the treatment of NE. © 2015 S. Karger AG, Basel.
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| 12. |
- Gressens, Pierre, et al.
(author)
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Pitfalls in the Quest of Neuroprotectants for the Perinatal Brain.
- 2011
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In: Developmental neuroscience. - : S. Karger AG. - 1421-9859 .- 0378-5866. ; 33:3-4, s. 189-198
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Journal article (peer-reviewed)abstract
- Sick preterm and term newborns are highly vulnerable to neural injury, and thus there has been a major search for new, safe and efficacious neuroprotective interventions in recent decades. Preclinical studies are essential to select candidate drugs for clinical trials in humans. This article focuses on 'negative' preclinical studies, i.e. studies where significant differences cannot be detected. Such findings are critical to inform both clinical and preclinical investigators, but historically they have been difficult to publish. A significant amount of time and resources is lost when negative results or nonpromising therapeutics are replicated in separate laboratories because these negative results were not shared with the research community in an open and accessible format. In this article, we discuss approaches to strengthen conclusions from negative preclinical studies and, conversely, to reduce false-negative preclinical evaluations of potential therapeutic compounds. Without being exhaustive, we address three major issues in conducting and interpreting preclinical experiments, including: (a) the choice of animal models, (b) the experimental design, and (c) issues concerning statistical analyses of the experiments. This general introduction is followed by synopses of negative data obtained from studies of three potential therapeutics for perinatal brain injury: (1) the somatostatin analog octreotide, (2) an AMPA/kainate receptor antagonist, topiramate, and (3) a pyruvate derivative, ethyl pyruvate.
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| 13. |
- Hagberg, Henrik, 1955, et al.
(author)
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Inflammation during fetal and neonatal life: implications for neurologic and neuropsychiatric disease in children and adults.
- 2012
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In: Annals of neurology. - : Wiley. - 1531-8249 .- 0364-5134. ; 71:4, s. 444-57
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Journal article (peer-reviewed)abstract
- Inflammation is increasingly recognized as being of both physiological and pathological importance in the immature brain. The rationale of this review is to present an update on this topic with focus on long-term consequences of inflammation during childhood and in adults. The immature brain can be exposed to inflammation in connection with viral or bacterial infection during pregnancy or as a result of sterile central nervous system (CNS) insults. Through efficient anti-inflammatory and reparative processes, inflammation may resolve without any harmful effects on the brain. Alternatively, inflammation contributes to injury or enhances CNS vulnerability. Acute inflammation can also be shifted to a chronic inflammatory state and/or adversely affect brain development. Hypothetically, microglia are the main immunocompetent cells in the immature CNS, and depending on the stimulus, molecular context, and timing, these cells will acquire various phenotypes, which will be critical regarding the CNS consequences of inflammation. Inflammation has long-term consequences and could speculatively modify the risk of a variety of neurological disorders, including cerebral palsy, autism spectrum disorders, schizophrenia, multiple sclerosis, cognitive impairment, and Parkinson disease. So far, the picture is incomplete, and data mostly experimental. Further studies are required to strengthen the associations in humans and to determine whether novel therapeutic interventions during the perinatal period can influence the occurrence of neurological disease later in life.
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| 14. |
- Hagberg, Henrik, 1955, et al.
(author)
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The role of inflammation in perinatal brain injury.
- 2015
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In: Nature Reviews Neurology. - : Springer Science and Business Media LLC. - 1759-4758 .- 1759-4766. ; 11:4, s. 192-208
-
Research review (peer-reviewed)abstract
- Inflammation is increasingly recognized as being a critical contributor to both normal development and injury outcome in the immature brain. The focus of this Review is to highlight important differences in innate and adaptive immunity in immature versus adult brain, which support the notion that the consequences of inflammation will be entirely different depending on context and stage of CNS development. Perinatal brain injury can result from neonatal encephalopathy and perinatal arterial ischaemic stroke, usually at term, but also in preterm infants. Inflammation occurs before, during and after brain injury at term, and modulates vulnerability to and development of brain injury. Preterm birth, on the other hand, is often a result of exposure to inflammation at a very early developmental phase, which affects the brain not only during fetal life, but also over a protracted period of postnatal life in a neonatal intensive care setting, influencing critical phases of myelination and cortical plasticity. Neuroinflammation during the perinatal period can increase the risk of neurological and neuropsychiatric disease throughout childhood and adulthood, and is, therefore, of concern to the broader group of physicians who care for these individuals.
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| 15. |
- Kichev, Anton, et al.
(author)
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TNF-related apoptosis-inducing ligand (TRAIL) signaling and cell death in the immature central nervous system after hypoxia-ischemia and inflammation.
- 2014
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In: The Journal of biological chemistry. - 1083-351X. ; 289:13, s. 9430-39
-
Journal article (peer-reviewed)abstract
- Tumor Necrosis Factor Related Apoptosis-Inducing Ligand (TRAIL) is a member of the TNF family. The interaction of TRAIL with death receptor 4 (DR4) and DR5 can trigger apoptotic cell death. The aim of this study was to investigate the role of TRAIL signaling in neonatal hypoxia-ischemia (HI). Using a neonatal mouse model of HI, mRNA and protein expression of TRAIL, DR5 and the TRAIL decoy receptors osteoprotegerin (OPG), mDcTRAILR1 and mDcTRAILR2 were determined. In vitro, mRNA expression of these genes was measured in primary neurons and oligodendrocyte progenitor cells (OPCs) after inflammatory cytokine (TNF-α/IFN-γ) treatment and/or oxygen and glucose deprivation (OGD). The toxicity of these various paradigms was also measured. The expression of TRAIL, DR5, OPG and mDcTRAILR2 was significantly increased after HI. In vitro, inflammatory cytokines and OGD treatment significantly induced mRNAs for TRAIL, DR5, OPG and mDcTRAILR2 in primary neurons, and of TRAIL and OPG in OPCs. TRAIL protein was expressed primarily in microglia and astroglia whereas DR5 co-localized with neurons and OPCs in vivo. OGD enhanced TNF-α/IFN-γ toxicity in both neuronal and OPC cultures. Recombinant TRAIL exerted toxicity alone or in combination with OGD and TNF-α/IFN-γ in primary neurons but not in OPC cultures. The marked increases in the expression of TRAIL and its receptors after cytokine exposure and OGD in primary neurons and OPCs were similar to those found in our animal model of neonatal HI. The toxicity of TRAIL in primary neurons suggests that TRAIL signaling participates in neonatal brain injury after inflammation and HI.
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| 16. |
- Koning, Gabriella, et al.
(author)
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Magnesium induces preconditioning of the neonatal brain via profound mitochondrial protection.
- 2019
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In: Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism. - 1559-7016. ; 39:6, s. 1038-1055
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Journal article (peer-reviewed)abstract
- Magnesium sulphate (MgSO4) given to women in preterm labor reduces cerebral palsy in their offspring but the mechanism behind this protection is unclear, limiting its effective, safe clinical implementation. Previous studies suggest that MgSO4 is not neuroprotective if administered during or after the insult, so we hypothesised that MgSO4 induces preconditioning in the immature brain. Therefore, we administered MgSO4 at various time-points before/after unilateral hypoxia-ischemia (HI) in seven-day-old rats. We found that MgSO4 treatment administered as a bolus between 6 days and 12h prior to HI markedly reduced the brain injury, with maximal protection achieved by 1.1mg/g MgSO4 administered 24h before HI. As serum magnesium levels returned to baseline before the induction of HI, we ascribed this reduction in brain injury to preconditioning. Cerebral blood flow was unaffected, but mRNAs/miRNAs involved in mitochondrial function and metabolism were modulated by MgSO4. Metabolomic analysis (H+-NMR) disclosed that MgSO4 attenuated HI-induced increases in succinate and prevented depletion of high-energy phosphates. MgSO4 pretreatment preserved mitochondrial respiration, reducing ROS production and inflammation after HI. Therefore, we propose that MgSO4 evokes preconditioning via induction of mitochondrial resistance and attenuation of inflammation.
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| 17. |
- Koning, Gabriella, et al.
(author)
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Magnesium sulphate induces preconditioning in preterm rodent models of cerebral hypoxia-ischemia.
- 2018
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In: International journal of developmental neuroscience : the official journal of the International Society for Developmental Neuroscience. - : Wiley. - 1873-474X. ; 70, s. 56-66
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Journal article (peer-reviewed)abstract
- Brain injury in preterm infants represents a substantial clinical problem associated with development of motor impairment, cognitive deficits and psychiatric problems. According to clinical studies, magnesium sulphate (MgSO4) given to women in preterm labor reduces the risk of cerebral palsy in the offspring but the mechanisms behind its neuroprotective effects are still unclear. Our aim was to explore whether MgSO4 induces tolerance (preconditioning) in the preterm rodent brain. For this purpose we established a model of perinatal hypoxia-ischemia (HI) in postnatal day 4 rats and also applied a recently developed postnatal day 5 mouse model of perinatal brain injury.Postnatal day 4 Wistar rats were exposed to unilateral carotid artery ligation followed by 60, 70 or 80min of hypoxia (8% O2). On postnatal day 11, brains were collected and macroscopically visible damage as well as white and grey matter injury was examined using immunohistochemical staining. Once the model had been established, a possible preconditioning protection induced by a bolus MgSO4 injection prior to 80min HI was examined 7days after the insult. Next, a MgSO4 bolus was injected in C57Bl6 mice on PND 4 followed by exposure to unilateral carotid artery ligation and hypoxia, (10% O2) for 70min on PND 5. Brains were collected 7days after the insult and examined with immunohistochemistry for grey and white matter injury.In rats, a 60min period of hypoxia resulted in very few animals with brain injury and although 70min of hypoxia resulted in a higher percentage of injured animals, the brains were marginally damaged. An 80min exposure of hypoxia caused cortical tissue damage combined with hippocampal atrophy and neuronal loss in the C3 hippocampal layer. In the rat model, MgSO4 (1.1mg/g administered i.p. 24h prior to the induction of HI, resulting in a transient serum Mg2+ concentration elevation to 4.1±0.2mmol/l at 3h post i.p. injection) reduced brain injury by 74% in grey matter and 64% in white matter. In the mouse model, MgSO4 (0.92mg/g) i.p. injection given 24h prior to the HI insult resulted in a Mg2+ serum concentration increase reaching 2.7±0.3mmol/l at 3h post injection, which conferred a 40% reduction in grey matter injury.We have established a postnatal day 4 rat model of HI for the study of preterm brain injury. MgSO4 provides a marked preconditioning protection both in postnatal day 4 rats and in postnatal day 5 mice.
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| 18. |
- Lingam, Ingran, et al.
(author)
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Serial blood cytokine and chemokine mRNA and microRNA over 48h are insult specific in a piglet model of inflammation-sensitized hypoxia-ischaemia.
- 2021
-
In: Pediatric research. - : Springer Science and Business Media LLC. - 1530-0447 .- 0031-3998. ; 89:3, s. 464-475
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Journal article (peer-reviewed)abstract
- Exposure to inflammation exacerbates injury in neonatal encephalopathy (NE). We hypothesized that brain biomarker mRNA, cytokine mRNA and microRNA differentiate inflammation (E. coli LPS), hypoxia (Hypoxia), and inflammation-sensitized hypoxia (LPS+Hypoxia) in an NE piglet model.Sixteen piglets were randomized: (i) LPS 2μg/kg bolus; 1μg/kg infusion (LPS; n=5), (ii) Saline with hypoxia (Hypoxia; n=6), (iii) LPS commencing 4h pre-hypoxia (LPS+Hypoxia; n=5). Total RNA was acquired at baseline, 4h after LPS and 1, 3, 6, 12, 24, 48h post-insult (animals euthanized at 48h). Quantitative PCR was performed for cytokines (IL1A, IL6, CXCL8, IL10, TNFA) and brain biomarkers (ENO2, UCHL1, S100B, GFAP, CRP, BDNF, MAPT). MicroRNA was detected using GeneChip (Affymetrix) microarrays. Fold changes from baseline were compared between groups and correlated with cell death (TUNEL) at 48h.Within 6h post-insult, we observed increased IL1A, CXCL8, CCL2 and ENO2 mRNA in LPS+Hypoxia and LPS compared to Hypoxia. IL10 mRNA differentiated all groups. Four microRNAs differentiated LPS+Hypoxia and Hypoxia: hsa-miR-23a, 27a, 31-5p, 193-5p. Cell death correlated with TNFA (R=0.69; p<0.01) at 1-3h and ENO2 (R=-0.69; p=0.01) at 48h.mRNA and miRNA differentiated hypoxia from inflammation-sensitized hypoxia within 6h in a piglet model. This information may inform human studies to enable triage for tailored neuroprotection in NE.Early stratification of infants with neonatal encephalopathy is key to provide tailored neuroprotection.IL1A, CXCL8, IL10, CCL2 and NSE mRNA are promising biomarkers of inflammation-sensitized hypoxia.IL10 mRNA levels differentiated all three pathological states; fold changes from baseline was the highest in LPS+Hypoxia animals, followed by LPS and Hypoxia at 6h.miR-23, -27, -31-5p and -193-5p were significantly upregulated within 6h of a hypoxia insult.Functional analysis highlighted the diverse roles of miRNA in the cellular processes.
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| 19. |
- Nair, Syam, et al.
(author)
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Neuroprotection offered by mesenchymal stem cells in perinatal brain injury: Role of mitochondria, inflammation and reactive oxygen species.
- 2021
-
In: Journal of neurochemistry. - : Wiley. - 1471-4159 .- 0022-3042. ; 158:1, s. 59-73
-
Research review (peer-reviewed)abstract
- Preclinical studies have shown that mesenchymal stem cell have a positive effect in perinatal brain injury models. The mechanisms that cause these neurotherapeutic effects are not entirely intelligible. Mitochondrial damage, inflammation and reactive oxygen species are considered to be critically involved in the development of injury. Mesenchymal stem cells have immunomodulatory action and exert mitoprotective effects which attenuate production of reactive oxygen species and promote restoration of tissue function and metabolism after perinatal insults. This review summarizes the present state, the underlying causes, challenges and possibilities for effective clinical translation of mesenchymal stem cell therapy.
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| 20. |
- Rangon, Claire-Marie, et al.
(author)
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Myelination induction by a histamine H3 receptor antagonist in a mouse model of preterm white matter injury.
- 2018
-
In: Brain, behavior, and immunity. - : Elsevier BV. - 1090-2139 .- 0889-1591. ; 74, s. 265-276
-
Journal article (peer-reviewed)abstract
- Fifteen million babies are born preterm every year and a significant number suffer from permanent neurological injuries linked to white matter injury (WMI). A chief cause of preterm birth itself and predictor of the severity of WMI is exposure to maternal-fetal infection-inflammation such as chorioamnionitis. There are no neurotherapeutics for this WMI. To affect this healthcare need, the repurposing of drugs with efficacy in other white matter injury models is an attractive strategy. As such, we tested the efficacy of GSK247246, an H3R antagonist/inverse agonist, in a model of inflammation-mediated WMI of the preterm born infant recapitulating the main clinical hallmarks of human brain injury, which are oligodendrocyte maturation arrest, microglial reactivity, and hypomyelination. WMI is induced by mimicking the effects of maternal-fetal infection-inflammation and setting up neuroinflammation. We induce this process at the time in the mouse when brain development is equivalent to the human third trimester; postnatal day (P)1 through to P5 with i.p. interleukin-1β (IL-1β) injections. We initiated GSK247246 treatment (i.p at 7mg/kg or 20mg/kg) after neuroinflammation was well established (on P6) and it was administered twice daily through to P10. Outcomes were assessed at P10 and P30 with gene and protein analysis. A low dose of GSK247246 (7mg/kg) lead to a recovery in protein expression of markers of myelin (density of Myelin Basic Protein, MBP & Proteolipid Proteins, PLP) and a reduction in macro- and microgliosis (density of ionising adaptor protein, IBA1 & glial fibrillary acid protein, GFAP). Our results confirm the neurotherapeutic efficacy of targeting the H3R for WMI seen in a cuprizone model of multiple sclerosis and a recently reported clinical trial in relapsing-remitting multiple sclerosis patients. Further work is needed to develop a slow release strategy for this agent and test its efficacy in large animal models of preterm infant WMI.
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