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

Neonatal resveratrol treatment in cerebral palsy model recovers neurodevelopment impairments by restoring the skeletal muscle morphology and decreases microglial activation in the cerebellum

Cerebral Palsy (CP) is the main motor disorder in childhood resulting from damage to the developing brain. Treatment perspectives are required to reverse the primary damage caused by the early insult and consequently to recover motor skills. Resveratrol has been shown to act as neuroprotection with benefits to skeletal muscle. This study aimed to investigate the effects of neonatal resveratrol treatment on neurodevelopment, skeletal muscle morphology, and cerebellar damage in CP model. Wistar rat pups were allocated to four experimental groups (n = 15/group) according CP model and treatment: Control+Saline (CS), Control+Resveratrol (CR), CP + Saline (CPS), and CP + Resveratrol (CPR). CP model associated anoxia and sensorimotor restriction. CP group showed delay in the disappearance of the palmar grasp reflex (p < 0.0001) and delay in the appearance of reflexes of negative geotaxis (p = 0.01), and free-fall righting (p < 0.0001), reduced locomotor activity and motor coordination (p < 0.05) than CS group. These motor skills impairments were associated with a reduction in muscle weight (p < 0.001) and area and perimeter of soleus end extensor digitorum longus muscle fibers (p < 0.0001), changes in muscle fibers typing pattern (p < 0.05), and the cerebellum showed signs of neuroinflammation due to elevated density and percentage of activated microglia in the CPS group compared to CS group (p < 0.05). CP animals treated with resveratrol showed anticipation of the appearance of negative geotaxis and free-fall righting reflexes (p < 0.01), increased locomotor activity (p < 0.05), recovery muscle fiber types pattern (p < 0.05), and reversal of the increase in density and the percentage of activated microglia in the cerebellum (p < 0.01). Thus, we conclude that neonatal treatment with resveratrol can contribute to the recovery of the delay neurodevelopment resulting from experimental CP due to its action in restoring the skeletal muscle morphology and reducing neuroinflammation from cerebellum.

Inflammation in Metal-Induced Neurological Disorders and Neurodegenerative Diseases

Essential metals play critical roles in maintaining human health as they participate in various physiological activities. Nonetheless, both excessive accumulation and deficiency of these metals may result in neurotoxicity secondary to neuroinflammation and the activation of microglia and astrocytes. Activation of these cells can promote the release of pro-inflammatory cytokines. It is well known that neuroinflammation plays a critical role in metal-induced neurotoxicity as well as the development of neurological disorders, such as Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS). Initially seen as a defense mechanism, persistent inflammatory responses are now considered harmful. Astrocytes and microglia are key regulators of neuroinflammation in the central nervous system, and their excessive activation may induce sustained neuroinflammation. Therefore, in this review, we aim to emphasize the important role and molecular mechanisms underlying metal-induced neurotoxicity. Our objective is to raise the awareness on metal-induced neuroinflammation in neurological disorders. However, it is not only just neuroinflammation that different metals could induce; they can also cause harm to the nervous system through oxidative stress, apoptosis, and autophagy, to name a few. The primary pathophysiological mechanism by which these metals induce neurological disorders remains to be determined. In addition, given the various pathways through which individuals are exposed to metals, it is necessary to also consider the effects of co-exposure to multiple metals on neurological disorders.

D-ribose-L-cysteine exhibits neuroprotective activity through inhibition of oxido-behavioral dysfunctions and modulated activities of neurotransmitters in the cerebellum of Juvenile mice exposed to ethanol

Alcohol exposure to the cerebellum has been known to trigger cerebellar dysfunctions through several mechanisms. This present study was designed to evaluate the repealing effect of D-ribose-L-cysteine (DRLC) on alcohol-induced cerebellar dysfunctions in juvenile BALB/c mice. The animals were randomly divided into 4 groups (n = 10 per group). Mice were given oral administration of normal saline (control), DRLC (100 mg/kg, p.o), ethanol (0.2 mL of 10% w/v), or DRLC (100 mg/kg, p.o) + ethanol (0.2 mL of 10% w/v). On day 29 of the study (i.e., 24 h after the administration of the last respective doses), neurochemical quantification of the respective levels of serotonin and dopamine, lipid peroxidation, total antioxidant, superoxide dismutase, and glutathione peroxidase in the cerebellar tissues of the mice were analyzed. Compared with the saline-treated group, the studied neurochemical indices were modulated across the various experimental groups. The administration of ethanol significantly modulates the levels of monoamine neurotransmitters (serotonin and dopamine) as well as contents of total antioxidants, activities of superoxide dismutase, and glutathione peroxidase, with a concurrently increased level of lipid peroxidase in the cerebellar tissue of the mice. DRLC significantly reverses these effects in the DRLC + ethanol co-treated group. Combined exposure to DRLC + ethanol counteracts the deleterious effect of ethanol in the cerebellum of juvenile BALB/c mice via monoamine neurotransmitter, lipid peroxidation, total antioxidant status, superoxide dismutase, and glutathione peroxidase action pathways. Therefore, DRLC could be a pharmacologic or therapeutic agent in attenuating the deleterious effects of alcohol on the cerebellum.

The Possible Role of Naringenin in the Prevention of Alcohol-Induced Neurochemical and Neurobehavioral Deficits

Chronic alcohol consumption is associated with progressive/irreversible neurodegeneration. However, there is not a clear understanding of its discrete pathophysiology or therapeutic intervention. The present study aimed to investigate the protective effect of the natural citrus flavonoid, naringenin (NAG), against alcohol-induced neurodegeneration in the brain cerebral cortex. Thirty-two male albino rats were randomly divided into four equal groups (eight rats each): control group (I); NAG-treated group (II); alcohol-intoxicated group (III) and alcohol + NAG co-treated group (IV). Brain nuclear factor erythroid 2-related factor 2 and receptor-interacting protein kinase 3 expression were assessed by real-time polymerase chain reaction. NAD(P)H quinone oxidoreductase 1 activity and malondialdehyde, reduced glutathione, mixed lineage kinase-like protein, phosphorylated glycogen synthase kinase 3 beta, and ciliary neurotrophic factor levels were all measured biochemically. B-cell lymphoma 2 expression was assessed by immunohistochemistry. A histopathological examination and neurobehavioral tests were performed. The alcohol-treated group showed a significant increase in oxidative stress and necroptosis biomarkers with a significant reduction in neuroprotective proteins. NAG co-administration effectively ameliorated cognitive dysfunction with an apparent neuroprotective effect by targeting various signaling pathways, including nuclear factor erythroid 2-related factor/NAD(P)H quinone oxidoreductase 1, anti-oxidant capacity, attenuated necroptosis, and upregulated neuroprotective ciliary neurotrophic factor. The study findings suggest NAG as a possible management strategy for alcohol-induced neurodegeneration.

Association of Oxidative Stress with Neurological Disorders

BACKGORUND

Oxidative stress is one of the main contributing factors involved in cerebral biochemical impairment. The higher susceptibility of the central nervous system to reactive oxygen species mediated damage could be attributed to several factors. For example, neurons use a greater quantity of oxygen, many parts of the brain have higher concentraton of iron, and neuronal mitochondria produce huge content of hydrogen peroxide. In addition, neuronal membranes have polyunsaturated fatty acids, which are predominantly vulnerable to oxidative stress (OS). OS is the imbalance between reactive oxygen species generation and cellular antioxidant potential. This may lead to various pathological conditions and diseases, especially neurodegenerative diseases such as, Parkinson's, Alzheimer's, and Huntington's diseases.

OBJECTIVES

In this study, we explored the involvement of OS in neurodegenerative diseases.

METHODS

We used different search terms like "oxidative stress and neurological disorders" "free radicals and neurodegenerative disorders" "oxidative stress, free radicals, and neurological disorders" and "association of oxidative stress with the name of disorders taken from the list of neurological disorders. We tried to summarize the source, biological effects, and physiologic functions of ROS.

RESULTS

Finally, it was noted that more than 190 neurological disorders are associated with oxidative stress.

CONCLUSION

More elaborated studies in the future will certainly help in understanding the exact mechanism involved in neurological diseases and provide insight into revelation of therapeutic targets.

Human pluripotent stem cell-derived ectomesenchymal stromal cells promote more robust functional recovery than umbilical cord-derived mesenchymal stromal cells after hypoxic-ischaemic brain damage

Aims: Hypoxic-ischaemic encephalopathy (HIE) is one of the most serious complications in neonates and infants. Mesenchymal stromal cell (MSC)-based therapy is emerging as a promising treatment avenue for HIE. However, despite its enormous potential, the clinical application of MSCs is limited by cell heterogeneity, low isolation efficiency and unpredictable effectiveness. In this study, we examined the therapeutic effects and underlying mechanisms of human pluripotent stem cell-derived ectomesenchymal stromal cells (hPSC-EMSCs) in a rat model of HIE.

Methods: hPSC-EMSCs were induced from either human embryonic stem cells or induced pluripotent stem cells. Stem cells or the conditioned medium (CM) derived from stem cells were delivered intracranially or intranasally to neonatal rats with HIE. Human umbilical cord-derived MSCs (hUC-MSCs) were used as the therapeutic comparison control and phosphate-buffered saline (PBS) was used as a negative control. Lesion size, apoptosis, neurogenesis, astrogliosis and microgliosis were evaluated. The rotarod test and Morris water maze were used to determine brain functional recovery. The PC-12 cell line, rat primary cortical neurons and neural progenitor cells were used to evaluate neurite outgrowth and the neuroprotective and neurogenesis effects of hPSC-EMSCs/hUC-MSCs. RNA-seq and enzyme-linked immunosorbent assays were used to determine the secretory factors that were differentially expressed between hPSC-EMSCs and hUC-MSCs. The activation and suppression of extracellular signal-regulated kinase (ERK) and cAMP response element-binding protein (CREB) were characterised using western blotting and immunofluorescent staining.

Results: hPSC-EMSCs showed a higher neuroprotective potential than hUC-MSCs, as demonstrated by a more significant reduction in lesion size and apoptosis in the rat brain following hypoxia-ischaemia (HI). Compared with PBS treatment, hPSC-EMSCs promoted endogenous neurogenesis and alleviated astrogliosis and microgliosis. hPSC-EMSCs were more effective than hUC-MSCs. hPSC-EMSCs achieved a greater recovery of brain function than hUC-MSCs and PBS in rats with HIE. CM derived from hPSC-EMSCs had neuroprotective and neurorestorative effects in vitro through anti-apoptotic and neurite outgrowth- and neurogenesis-promoting effects. Direct comparisons between hPSC-EMSCs and hUC-MSCs revealed the significant enrichment of a group of secretory factors in hPSC-EMSCs, including nerve growth factor (NGF), platelet-derived growth factor-AA and transforming growth factor-β₂, which are involved in neurogenesis, synaptic transmission and neurotransmitter transport, respectively. Mechanistically, the CM derived from hPSC-EMSCs was found to potentiate NGF-induced neurite outgrowth and the neuronal differentiation of NPCs via the ERK/CREB pathway. Suppression of ERK or CREB abolished CM-potentiated neuritogenesis and neuronal differentiation. Finally, intranasal delivery of the CM derived from hPSC-EMSCs significantly reduced brain lesion size, promoted endogenous neurogenesis, mitigated inflammatory responses and improved functional recovery in rats with HIE.

Conclusion: hPSC-EMSCs promote functional recovery after HI through multifaceted neuromodulatory activities via paracrine/trophic mechanisms. We propose the use of hPSC-EMSCs for the treatment of HIE, as they offer an excellent unlimited cellular source of MSCs.

Multi-Hit White Matter Injury-Induced Cerebral Palsy Model Established by Perinatal Lipopolysaccharide Injection

Cerebral palsy (CP) is a group of permanent, but not unchanging, disorders of movement and/or posture and motor function. Since the major brain injury associated with CP is white matter injury (WMI), especially, in preterm infants, we established a "multi-hit" rat model to mimic human WMI in symptomatology and at a histological level. In our WMI model, pups suffering from limb paresis, incoordination, and direction difficulties fit the performance of CP. Histologically, they present with fewer neural cells, inordinate fibers, and more inflammatory cell infiltration, compared to the control group. From the electron microscopy results, we spotted neuronal apoptosis, glial activation, and myelination delay. Besides, the abundant appearance of IBA1-labeled microglia also implied that microglia play a role during neuronal cell injury. After activation, microglia shift between the pro-inflammatory M1 type and the anti-inflammatory M2 type. The results showed that LPS/infection stimulated IBA1 + (marked activated microglia) expression, downregulated CD11c + (marked M1 phenotype), and upregulated Arg 1 + (marked M2 phenotype) protein expression. It indicated an M1 to M2 transition after multiple infections. In summary, we established a "multi-hit" WMI-induced CP rat model and demonstrated that the microglial activation correlates tightly with CP formation, which may become a potential target for future studies.

Locomotion is impacted differently according to the perinatal brain injury model: Meta-analysis of preclinical studies with implications for cerebral palsy

BACKGROUND

Different approaches to reproduce cerebral palsy (CP) in animals, contribute to the knowledge of the pathophysiological mechanism of this disease and provide a basis for the development of intervention strategies. Locomotion and coordination are the main cause of disability in CP, however, few studies highlight the quantitative differences of CP models, on locomotion parameters, considering the methodologies to cause brain lesions in the perinatal period.

METHODS

Studies with cerebral palsy animal models that assess locomotion parameters were systematically retrieved from Medline/PubMed, SCOPUS, LILACS, and Web of Science. Methodological evaluation of included studies and quantitative assessment of locomotion parameters were performed after eligibility screening.

RESULTS

CP models were induced by hypoxia-ischemia (HI), Prenatal ischemia (PI), lipopolysaccharide inflammation (LPS), intraventricular haemorrhage (IVH), anoxia (A), sensorimotor restriction (SR), and a combination of different models. Overall, 63 studies included in qualitative synthesis showed a moderate quality of evidence. 16 studies were included in the quantitative meta-analysis. Significant reduction was observed in models that combined LPS with HI related to distance traveled (SMD -7.24 95 % CI [-8.98, -5.51], Z = 1.18, p < 0.00001) and LPS with HI or anoxia with sensory-motor restriction (SMD -6.01, 95 % CI [-7.67, -4.35], Z = 7.11), or IVH (SMD -4.91, 95 % CI [-5.84, -3.98], Z = 10.31, p < 0.00001) related to motor coordination.

CONCLUSION

The combination of different approaches to reproduce CP in animals causes greater deficits in locomotion and motor coordination from the early stages of life to adulthood. These findings contribute to methodological refinement, reduction, and replacement in animal experimentation, favoring translational purposes.

Behavioral Alterations and Decreased Number of Parvalbumin-Positive Interneurons in Wistar Rats after Maternal Immune Activation by Lipopolysaccharide: Sex Matters

Maternal immune activation (MIA) during pregnancy represents an important environmental factor in the etiology of schizophrenia and autism spectrum disorders (ASD). Our goal was to investigate the impacts of MIA on the brain and behavior of adolescent and adult offspring, as a rat model of these neurodevelopmental disorders. We injected bacterial lipopolysaccharide (LPS, 1 mg/kg) to pregnant Wistar dams from gestational day 7, every other day, up to delivery. Behavior of the offspring was examined in a comprehensive battery of tasks at postnatal days P45 and P90. Several brain parameters were analyzed at P28. The results showed that prenatal immune activation caused social and communication impairments in the adult offspring of both sexes; males were affected already in adolescence. MIA also caused prepulse inhibition deficit in females and increased the startle reaction in males. Anxiety and hypolocomotion were apparent in LPS-affected males and females. In the 28-day-old LPS offspring, we found enlargement of the brain and decreased numbers of parvalbumin-positive interneurons in the frontal cortex in both sexes. To conclude, our data indicate that sex of the offspring plays a crucial role in the development of the MIA-induced behavioral alterations, whereas changes in the brain apparent in young animals are sex-independent.

Experimental cerebral palsy causes microstructural brain damage in areas associated to motor deficits but no spatial memory impairments in the developing rat

INTRODUCTION

Cerebral palsy (CP) is the major cause of motor and cognitive impairments during childhood. CP can result from direct or indirect structural injury to the developing brain. In this study, we aimed to describe brain damage and behavioural alterations during early adult life in a CP model using the combination of maternal inflammation, perinatal anoxia and postnatal sensorimotor restriction.

METHODS

Pregnant Wistar rats were injected intraperitoneally with 200 µg/kg LPS at embryonic days E18 and E19. Between 3 and 6 h after birth (postnatal day 0 - PND0), pups of both sexes were exposed to anoxia for 20 min. From postnatal day 2 to 21, hindlimbs of animals were immobilized for 16 h daily during their active phase. From PND40, locomotor and cognitive tests were performed using Rota-Rod, Ladder Walking and Morris water Maze. Ex-vivo MRI Diffusion Tensor Imaging (DTI) and Neurite Orientation Dispersion and Density Imaging (NODDI) were used to assess macro and microstructural damage and brain volume alterations induced by the model. Myelination and expression of neuronal, astroglial and microglial markers, as well as apoptotic cell death were evaluated by immunofluorescence.

RESULTS

CP animals showed decreased body weight, deficits in gross (rota-rod) and fine (ladder walking) motor tasks compared to Controls. No cognitive impairments were observed. Ex-vivo MRI showed decreased brain volumes and impaired microstructure in the cingulate gyrus and sensory cortex in CP brains. Histological analysis showed increased cell death, astrocytic reactivity and decreased thickness of the corpus callosum and altered myelination in CP animals. Hindlimb primary motor cortex analysis showed increased apoptosis in CP animals. Despite the increase in NeuN and GFAP, no differences between groups were observed as well as no co-localization with the apoptotic marker. However, an increase in Iba-1+ microglia with co-localization to cleaved caspase 3 was observed.

CONCLUSION

Our results suggest that experimental CP induces long-term brain microstructural alterations in myelinated structures, cell death in the hindlimb primary motor cortex and locomotor impairments. Such new evidence of brain damage could help to better understand CP pathophysiological mechanisms and guide further research for neuroprotective and neurorehabilitative strategies for CP patients.

Oxidative Stress and Neurodevelopmental Outcomes in Rat Offspring with Intrauterine Growth Restriction Induced by Reduced Uterine Perfusion

Intrauterine growth restriction (IUGR) is a major cause of morbidity and mortality and is worldwide associated with delayed neurodevelopment. The exact mechanism involved in delayed neurodevelopment associated with IUGR is still unclear. Reduced uterine perfusion (RUP) is among the main causes of placental insufficiency leading to IUGR, which is associated with increases in oxidative stress. This study investigated whether oxidative stress is associated with delayed neurodevelopment in IUGR rat pups. Pregnant rats were exposed to RUP surgery on gestational day 14 to generate IUGR rat offspring. We evaluated offspring’s morphometric at birth, and neurodevelopment on postnatal day 21 (PD21) as well as markers of oxidative stress in plasma and brain. Offspring from dams exposed to RUP showed significant (p < 0.05) lower birth weight compared to controls, indicating IUGR. Motor and cognitive deficits, and levels of oxidative stress markers, were significantly (p < 0.05) elevated in IUGR offspring compared to controls. IUGR offspring showed significant (p < 0.05) negative correlations between brain lipid peroxidation and neurocognitive tests (open field and novel object recognition) in comparison with controls. Our findings suggest that neurodevelopmental delay observed in IUGR rat offspring is associated with increased levels of oxidative stress markers.

Neurological Outcome Following Newborn Encephalopathy With and Without Perinatal Infection: A Systematic Review

Background: Studies have suggested that neurological outcome may differ in newborns with encephalopathy with and without perinatal infection. We aimed to systematically review this association. Methods: We conducted this systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Studies were obtained from four databases including Pubmed, Embase, Web of Science, and The Cochrane Database. Newborns with encephalopathy with and without markers of perinatal infection were compared with regard to neurodevelopmental assessments, neurological disorders, and early biomarkers of brain damage. Risk of bias and quality of evidence were assessed by the Newcastle-Ottawa scale and Grading of Recommendations Assessment, Development and Evaluation (GRADE). Results: We screened 4,284 studies of which eight cohort studies and one case-control study met inclusion criteria. A narrative synthesis was composed due to heterogeneity between studies. Six studies were classified as having low risk of bias, while three studies were classified as having high risk of bias. Across all outcomes, the quality of evidence was very low. The neurological outcome was similar in newborns with encephalopathy with and without markers of perinatal infection. Conclusions: Further studies of higher quality are needed to clarify whether perinatal infection may affect neurological outcome following newborn encephalopathy. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42020185717.

Attenuation of chronic arsenic neurotoxicity via melatonin in male offspring of maternal rats exposed to arsenic during conception: Involvement of oxidative DNA damage and inflammatory signaling cascades

Prenatal exposure to arsenic is demonstrated to elevate the risk of brain damage and neurological disorders in the fetus, mainly due to its ability for crossing through the placental barriers. Increase in oxidative stress, inflammation, and DNA damage is main mechanisms of arsenic-induced neurotoxicity. Therefore, this study aimed to evaluate the neuroprotective effects of melatonin, as a potent anti-oxidant and anti-inflammatory agent against arsenic toxicity in the brains of male offspring rats. Pregnant mother rats were randomly assigned into four groups including group I, as control, group II received 10 mg/kg melatonin, group III received arsenic at 50 mg/kg, and group IV received melatonin and arsenic. After a two-month period, oxidative stress, DNA damage, inflammation and apoptosis were assessed in the male offspring rats. Exposure to arsenic significantly increased the pro-inflammatory and oxidative factors resulting in DNA damage and apoptosis in the brain tissues of offspring rats in comparison to controls (p < 0.05). Exogenous administration of melatonin showed a significant increase in the tissue levels of acetylcholine esterase, decrease in the lactate dehydrogenase and myeloperoxidase, when compared to arsenic group (p < 0.05). Melatonin also overcame the arsenic-induced oxidative stress and suppressed inflammation, DNA damage and apoptosis. Our results suggested that melatonin may be a promising neuro-protective agent and momentous therapy for the treatment of arsenic-toxicity in clinical conditions.

Lipopolysaccharide-Induced Systemic Inflammation in the Neonatal Period Increases Microglial Density and Oxidative Stress in the Cerebellum of Adult Rats

Inflammatory processes occurring in the perinatal period may affect different brain regions, resulting in neurologic sequelae. Injection of lipopolysaccharide (LPS) at different neurodevelopmental stages produces long-term consequences in several brain structures, but there is scarce evidence regarding alterations in the cerebellum. The aim of this study was to evaluate the long-term consequences on the cerebellum of a systemic inflammatory process induced by neonatal LPS injection. For this, neonatal rats were randomly assigned to three different groups: naïve, sham, and LPS. Saline (sham group) or LPS solution (1 mg/kg) was intraperitoneally injected on alternate postnatal days (PN) PN1, PN3, PN5, and PN7. Spontaneous activity was evaluated with the open field test in adulthood. The cerebellum was evaluated for different parameters: microglial and Purkinje cell densities, oxidative stress levels, and tumor necrosis factor alpha (TNF-α) mRNA expression. Our results show that administration of LPS did not result in altered spontaneous activity in adult animals. Our data also indicate increased oxidative stress in the cerebellum, as evidenced by an increase in superoxide fluorescence by dihydroethidium (DHE) indicator. Stereological analyses indicated increased microglial density in the cerebellum that was not accompanied by Purkinje cell loss or altered TNF-α expression in adult animals. Interestingly, Purkinje cells ectopically positioned in the granular and molecular layers of the cerebellum were observed in animals of the LPS group. Our data suggest that neonatal LPS exposure causes persistent cellular and molecular changes to the cerebellum, indicating the susceptibility of this region to systemic inflammatory insults in infancy. Further investigation of the consequences of these changes and the development of strategies to avoid those should be subject of future studies.

Cannabinoid-mediated Modulation of Oxidative Stress and Early Inflammatory Response after Hypoxia-Ischemia

In the process of neonatal encephalopathy, oxidative stress and neuroinflammation have a prominent role after perinatal asphyxia. With the exception of therapeutic hypothermia, no therapeutic interventions are available in the clinical setting to target either the oxidative stress or inflammation, despite the high prevalence of neurological sequelae of this devastating condition. The endocannabinoid system (ECS), recently recognized as a widespread neuromodulatory system, plays an important role in the development of the central nervous system (CNS). This study aims to evaluate the potential effect of the cannabinoid (CB) agonist WIN 55,212-2 (WIN) on reactive oxygen species (ROS) and early inflammatory cytokine production after hypoxia–ischemia (HI) in fetal lambs. Hypoxic–ischemic animals were subjected to 60 min of HI by partial occlusion of the umbilical cord. A group of lambs received a single dose of 0.01 μg/kg WIN, whereas non-asphyctic animals served as controls. WIN reduced the widespread and notorious increase in inflammatory markers tumor necrosis factor (TNF)-α and interleukin (IL)-1β and IL-6 induced by HI, a modulatory effect not observed for oxidative stress. Our study suggests that treatment with a low dose of WIN can alter the profile of pro-inflammatory cytokines 3 h after HI.

IL-1 receptor antagonist therapy mitigates placental dysfunction and perinatal injury following Zika virus infection

Zika virus (ZIKV) infection during pregnancy causes significant adverse sequelae in the developing fetus, and results in long-term structural and neurologic defects. Most preventive and therapeutic efforts have focused on the development of vaccines, antivirals, and antibodies. The placental immunologic response to ZIKV, however, has been largely overlooked as a target for therapeutic intervention. The placental inflammatory response, specifically IL-1β secretion and signaling, is induced by ZIKV infection and represents an environmental factor that is known to increase the risk of perinatal developmental abnormalities. We show in a mouse model that maternally administrated IL-1 receptor antagonist (IRA; Kineret, or anakinra), following ZIKV exposure, can preserve placental function (by improving trophoblast invasion and placental vasculature), increase fetal viability, and reduce neurobehavioral deficits in the offspring. We further demonstrate that while ZIKV RNA is highly detectable in placentas, it is not correlated with fetal viability. Beyond its effects in the placenta, we show that IL-1 blockade may also directly decrease fetal neuroinflammation by mitigating fetal microglial activation in a dose-dependent manner. Our studies distinguish the role of placental inflammation during ZIKV-infected pregnancies, and demonstrate that maternal IRA may attenuate fetal neuroinflammation and improve perinatal outcomes.

Morphofunctional characteristics of skeletal muscle in rats with cerebral palsy

Knowledge of skeletal muscle adaptations is important to understand the functional deficits in cerebral palsy (CP). This study aimed to investigate the morphofunctional characteristics of skeletal muscle in a CP animal model. Initially, pregnant Wistar rats were injected intraperitoneally with saline or lipopolysaccharide over the last five days of pregnancy. The control group (n = 8) consisted of male pups born to females injected with saline. The CP group (n = 8) consisted of male pups born to females injected with lipopolysaccharide, which were submitted to perinatal anoxia [day of birth, postnatal day 0 (P0)] and sensorimotor restriction (P1-P30). The open-field test was undertaken on P29 and P45. On P48, the animals were weighed, and the plantaris muscle was collected and its weight and length were measured. Transverse sections were stained with haematoxylin-eosin, NADH-TR, Masson's trichrome and non-specific esterase reaction for analysis. and transmission electron microscopy was performed. In the CP group, reductions were observed in mobility time, number of crossings and rearing frequency, body weight, muscle weight and length, and nucleus-to-fibre and capillary-to-fibre ratios. There was a statistically significant increase in the percentage area of the muscle section occupied by collagen; reduction in the area and increase in the number of type I muscle fibres; increase in myofibrillar disorganization and Z-line disorganization and dissolution; and reduction in the area and largest and smallest diameters of neuromuscular junctions. Thus this animal model of CP produced morphofunctional alterations in skeletal muscle, that were associated with evidence of motor deficits as demonstrated by the open-field test.

Acyl-CoA synthetase 6 enriches the neuroprotective omega-3 fatty acid DHA in the brain

Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is highly abundant in the brain and confers protection against numerous neurological diseases, yet the fundamental mechanisms regulating the enrichment of DHA in the brain remain unknown. Here, we have discovered that a member of the long-chain acyl-CoA synthetase family, Acsl6, is required for the enrichment of DHA in the brain by generating an Acsl6-deficient mouse (Acsl6^-/-). Acsl6 is highly enriched in the brain and lipid profiling of Acsl6^-/- tissues reveals consistent reductions in DHA-containing lipids in tissues highly abundant with Acsl6. Acsl6^-/- mice demonstrate motor impairments, altered glutamate metabolism, and increased astrogliosis and microglia activation. In response to a neuroinflammatory lipopolysaccharide injection, Acsl6^-/- brains show similar increases in molecular and pathological indices of astrogliosis compared with controls. These data demonstrate that Acsl6 is a key mediator of neuroprotective DHA enrichment in the brain.

Melatonin treatment in fetal and neonatal diseases

This literature review aims to address the main scientific findings on oxidative stress activity in different gestational disorders, as well as the function and application of melatonin in the treatment of fetal and neonatal changes. Oxidative stress has been associated with the etiopathogenesis of recurrent miscarriages, preeclampsia, intrauterine growth restriction, and stillbirth. Both, the exacerbated consumption of the antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase, and the increased synthesis of reactive oxygen species, such as superoxide, peroxynitrite, and hydrogen peroxide, induce phospholipid peroxidation and endothelial dysfunction, impaired invasion and death of trophoblast cells, impaired decidualization, and remodeling of maternal spiral arteries. It has been postulated that melatonin induces specific biochemical responses that regulate cell proliferation in fetuses, and that its antioxidant action promotes bioavailability of nitric oxide and, thus, placental perfusion and also fetal nutrition and oxygenation. Therefore, the therapeutic action of melatonin has been the subject of major studies that aim to minimize or prevent different injuries affecting this pediatric age group, such as intrauterine growth restriction, encephalopathy, chronic lung diseases, retinopathy of prematurity Conclusion: the results antioxidant and indicate that melatonin is an important therapy for the clinical treatment of these diseases.

Protective effects of quercetin against brain injury in a rat model of lipopolysaccharide-induced fetal brain injury

Maternal exposure to lipopolysaccharide (LPS), a bacterial endotoxin produced during infection, leads to disruption in fetal brain development and causes newborn brain injury. Quercetin (QR) is a multipotent flavonoid that functions as an antioxidant and protects against inflammation and neurodegeneration. In this study, we explored the potential functions of QR in alleviating maternal LPS exposure induced fetal brain damage. Pregnant rats at late gestational stages were treated with saline, LPS, QR, LPS and QR. Brain injury biomarker TGF-1β was assessed in cerebrospinal fluid (CSF) and brain tissue of newborn rats. Pro-inflammatory cytokines, apoptosis markers and oxidative stress indicators were evaluated. We found that LPS treatment induced an increased production of TGF-1β which was suppressed by QR administration. LPS enhanced pro-apoptotic Bax and inhibited anti-apoptotic Bcl-2 expression. QR reduced that ratio of Bax and Bcl-2 that was high in LPS treated brain tissue. Additionally, QR suppressed oxidative stress induced by LPS. Finally, QR reduced the levels of pro-inflammatory cytokines that were produced as a result of LPS exposure. In summary, our study indicates that QR potently alleviates maternal LPS exposure induced fetal brain injury in rats, making it a potential therapeutic for suppressing infant brain damage as a result of maternal infection.

Prenatal exposure to environmental insults and enhanced risk of developing Schizophrenia and Autism Spectrum Disorder: focus on biological pathways and epigenetic mechanisms

When considering neurodevelopmental disorders (NDDs), Schizophrenia (SZ) and Autism Spectrum Disorder (ASD) are considered to be among the most severe in term of prevalence, morbidity and impact on the society. Similar features and overlapping symptoms have been observed at multiple levels, suggesting common pathophysiological bases. Indeed, recent genome-wide association studies (GWAS) and epidemiological data report shared vulnerability genes and environmental triggers across the two disorders. In this review, we will discuss the possible biological mechanisms, including glutamatergic and GABAergic neurotransmissions, inflammatory signals and oxidative stress related systems, which are targeted by adverse environmental exposures and that have been associated with the development of SZ and ASD. We will also discuss the emerging role of the gut microbiome as possible interplay between environment, immune system and brain development. Finally, we will describe the involvement of epigenetic mechanisms in the maintenance of long-lasting effects of adverse environments early in life. This will allow us to better understand the pathophysiology of these NDDs, and also to identify novel targets for future treatment strategies.

Protective effect against brain tissues oxidative damage as a possible mechanism for beneficial effects of L-arginine on lipopolysaccharide induced memory impairment in rats

L-Arginine (LA) and nitric oxide (NO) have been suggested to have some effects on learning, memory, brain tissues oxidative damage, and neuroinflammation. In this study, protective effect against brain tissues oxidative damage as a possible mechanism for beneficial effects of LA on lipopolysaccharide (LPS) induced memory impairment was investigated. The rats were grouped into and treated by (1) control (saline), (2) LPS (1 mg/kg, IP), (3) LA (200 mg/kg) - LPS (4) LA. In passive avoidance (PA) test, LPS administration shortened the latency to enter the dark compartment in LPS group compared to control (p < .001) which was accompanied with a high level of malondialdehyde (MDA) and NO metabolite concentrations in the hippocampal tissues (p < .001and p < .05, respectively). Pretreatment with LA prolonged the latency in LA-LPS group compared with LPS group (p < .01-.001) and re-stored MDA and NO metabolites in the hippocampal tissues (p < .05). LPS also reduced superoxide dismutase (SOD) and catalase (CAT) activities and thiol content in the hippocampal tissues in LPS group compared to control (p < .05 and p < .001, respectively) which improved by LA when it was administered before LPS in LA-LPS group (p < .05 and p < .001). Finally, the serum TNFα level of LPS group was higher than the control (p < .01) while, in LA-LPS group it was lower than LPS group (p < .01). It seems that the beneficial effects of LA on memory impairment of LPS-treated rats may be due to its protective effects against brain tissues oxidative damage.

Glucocorticoids Protect Neonatal Rat Brain in Model of Hypoxic-Ischemic Encephalopathy (HIE)

Hypoxic-ischemic encephalopathy (HIE) resulting from asphyxia in the peripartum period is the most common cause of neonatal brain damage and can result in significant neurologic sequelae, including cerebral palsy. Currently therapeutic hypothermia is the only accepted treatment in addition to supportive care for infants with HIE, however, many additional neuroprotective therapies have been investigated. Of these, glucocorticoids have previously been shown to have neuroprotective effects. HIE is also frequently compounded by infectious inflammatory processes (sepsis) and as such, the infants may be more amenable to treatment with an anti-inflammatory agent. Thus, the present study investigated dexamethasone and hydrocortisone treatment given after hypoxic-ischemic (HI) insult in neonatal rats via intracerebroventricular (ICV) injection and intranasal administration. In addition, we examined the effects of hydrocortisone treatment in HIE after lipopolysaccharide (LPS) sensitization in a model of HIE and sepsis. We found that dexamethasone significantly reduced rat brain infarction size when given after HI treatment via ICV injection; however it did not demonstrate any neuroprotective effects when given intranasally. Hydrocortisone after HI insult also significantly reduced brain infarction size when given via ICV injection; and the intranasal administration showed to be protective of brain injury in male rats at a dose of 300 µg. LPS sensitization did significantly increase the brain infarction size compared to controls, and hydrocortisone treatment after LPS sensitization showed a significant decrease in brain infarction size when given via ICV injection, as well as intranasal administration in both genders at a dose of 300 µg. To conclude, these results show that glucocorticoids have significant neuroprotective effects when given after HI injury and that these effects may be even more pronounced when given in circumstances of additional inflammatory injury, such as neonatal sepsis.

N-acetylcysteine attenuates lipopolysaccharide-induced impairment in lamination of Ctip2-and Tbr1- expressing cortical neurons in the developing rat fetal brain

Oxidative stress and inflammatory insults are the major instigating events of bacterial intrauterine infection that lead to fetal brain injury. The purpose of this study is to investigate the remedial effects of N-acetyl-cysteine (NAC) for inflammation-caused deficits in brain development. We found that lipopolysaccharide (LPS) induced reactive oxygen species (ROS) production by RAW264.7 cells. Macrophage-conditioned medium caused noticeable cortical cell damage, specifically in cortical neurons. LPS at 25 μg/kg caused more than 75% fetal loss in rats. An increase in fetal cortical thickness was noted in the LPS-treated group. In the enlarged fetal cortex, laminar positioning of the early born cortical cells expressing Tbr1 and Ctip2 was disrupted, with a scattered distribution. The effect was similar, but minor, in later born Satb2-expressing cortical cells. NAC protected against LPS-induced neuron toxicity in vitro and counteracted pregnancy loss and alterations in thickness and lamination of the neocortex in vivo. Fetal loss and abnormal fetal brain development were due to LPS-induced ROS production. NAC is an effective protective agent against LPS-induced damage. This finding highlights the key therapeutic impact of NAC in LPS-caused abnormal neuronal laminar distribution during brain development.

Prenatal maternal lipopolysaccharide administration leads to age- and region-specific oxidative stress in the early developmental stage in offspring

Prenatal exposure to lipopolysaccharide (LPS) has been exploited to simulate brain disorder in animal model. Prenatal LPS-exposure has shown elevated levels of pro-inflammatory cytokines in the early stages of the postnatal period. This study determines the effect of prenatal LPS-exposure on oxidative stress (OS) in the distinct brain regions in the early postnatal stages. LPS (50 μg/kg, i.p.) and water for injection (100 μl, i.p.) were given to the experimental (n=5) and control (n=5) group of pregnant Swiss albino mice respectively on gestational day (GD)-16 and 17. Animals were decapitated on postnatal day (PnD) - 1, 7, 14 and 21 to assay levels of oxidative markers from 6 distinct brain regions. When compared with the control, prenatal LPS-exposure alters levels of OS markers: (i) on PnD-1, glutathione (GSH) level is raised and superoxide dismutase (SOD) activity is dropped, (ii) on PnD-7, advanced oxidation of protein product (AOPP) level is elevated, (iii) on PnD-14, lipid peroxidation (MDA) and activity of catalase (CAT) are enhanced, (iv) on PnD-21, increased MDA continued. The hippocampus (HC) and cerebellum (CB) were mostly susceptible to OS in the early postnatal development. Levels of MDA and activity of CAT enzyme were increased on PnD-14 in the cortex, HC and CB. Except MDA, all OS markers recovered and returned to the level of control animals on PnD-21. Taken together, these results suggest that prenatal LPS-exposure induces age- and region-specific OS in the early postnatal stage.

Ventilation strategies for preventing oxidative stress-induced injury in preterm infants with respiratory disease: an update

Reactive oxygen and nitrogen species are produced by several inflammatory and structural cells of the airways. The lungs of preterm newborns are susceptible to oxidative injury induced by both reactive oxygen and nitrogen species. Increased oxidative stress and imbalance in antioxidant enzymes may play a role in the pathogenesis of inflammatory pulmonary diseases. Preterm infants are frequently exposed to high oxygen concentrations, infections or inflammation; they have reduced antioxidant defense and high free iron levels which enhance toxic radical generation. Multiple ventilation strategies have been studied to reduce injury and improve outcomes in preterm infants. Using lung protective strategies, there is the need to reach a compromise between satisfaction of gas exchange and potential toxicities related to over-distension, derecruitment of lung units and high oxygen concentrations. In this review, the authors summarize scientific evidence concerning oxidative stress as it relates to resuscitation in the delivery room and to the strategies of ventilation.

Superoxide induces protein oxidation in plasma and TNF-α elevation in macrophage culture: Insights into mechanisms of neurotoxicity following doxorubicin chemotherapy

Chemotherapy-induced cognitive impairment (CICI) is a quality of life-altering consequence of chemotherapy experienced by a large percentage of cancer survivors. Approximately half of FDA-approved anti-cancer drugs are known to produce ROS. Doxorubicin (Dox), a prototypical ROS-generating chemotherapeutic agent, generates superoxide (O2(-)•) via redox cycling. Our group previously demonstrated that Dox, which does not cross the BBB, induced oxidative damage to plasma proteins leading to TNF-α elevation in the periphery and, subsequently, in brain following cancer chemotherapy. We hypothesize that such processes play a central role in CICI. The current study tested the notion that O2(-)• is involved and likely responsible for Dox-induced plasma protein oxidation and TNF-α release. Addition of O2(-)• as the potassium salt (KO2) to plasma resulted in significantly increased oxidative damage to proteins, indexed by protein carbonyl (PC) and protein-bound HNE levels. We then adapted this protocol for use in cell culture. Incubation of J774A.1 macrophage culture using this KO2-18crown6 protocol with 1 and 10 µM KO2 resulted in dramatically increased levels of TNF-α produced. These findings, together with our prior results, provide strong evidence that O2(-)• and its resulting reactive species are critically involved in Dox-induced plasma protein oxidation and TNF-α release.

Hypoxic Preconditioning Suppresses Glial Activation and Neuroinflammation in Neonatal Brain Insults

Perinatal insults and subsequent neuroinflammation are the major mechanisms of neonatal brain injury, but there have been only scarce reports on the associations between hypoxic preconditioning and glial activation. Here we use neonatal hypoxia-ischemia brain injury model in 7-day-old rats and in vitro hypoxia model with primary mixed glial culture and the BV-2 microglial cell line to assess the effects of hypoxia and hypoxic preconditioning on glial activation. Hypoxia-ischemia brain insult induced significant brain weight reduction, profound cell loss, and reactive gliosis in the damaged hemisphere. Hypoxic preconditioning significantly attenuated glial activation and resulted in robust neuroprotection. As early as 2 h after the hypoxia-ischemia insult, proinflammatory gene upregulation was suppressed in the hypoxic preconditioning group. In vitro experiments showed that exposure to 0.5% oxygen for 4 h induced a glial inflammatory response. Exposure to brief hypoxia (0.5 h) 24 h before the hypoxic insult significantly ameliorated this response. In conclusion, hypoxic preconditioning confers strong neuroprotection, possibly through suppression of glial activation and subsequent inflammatory responses after hypoxia-ischemia insults in neonatal rats. This might therefore be a promising therapeutic approach for rescuing neonatal brain injury.

Neonatal anoxia in rats: hippocampal cellular and subcellular changes related to cell death and spatial memory

Neonatal anoxia in rodents has been used to understand brain changes and cognitive dysfunction following asphyxia. This study investigated the time-course of cellular and subcellular changes and hippocampal cell death in a non-invasive model of anoxia in neonatal rats, using Terminal deoxynucleotidyl transferase-mediated dUTP Nick End Labeling (TUNEL) to reveal DNA fragmentation, Fluoro-Jade® B (FJB) to show degenerating neurons, cleaved caspase-3 immunohistochemistry (IHC) to detect cells undergoing apoptosis, and transmission electron microscopy (TEM) to reveal fine ultrastructural changes related to cell death. Anoxia was induced by exposing postnatal day 1 (P1) pups to a flow of 100% gaseous nitrogen for 25 min in a chamber maintained at 37 °C. Control rats were similarly exposed to this chamber but with air flow instead of nitrogen. Brain changes following anoxia were evaluated at postnatal days 2, 14, 21 and 60 (P2, P14, P21 and P60). In addition, spatial reference memory following anoxia and control treatments was evaluated in the Morris water maze, starting at P60. Compared to their respective controls, P2 anoxic rats exhibited (1) higher TUNEL labeling in cornus ammonis (CA) 1 and the dentate gyrus (DG), (2) higher FJB-positive cells in the CA2-3, and (3) somato-dendritic swelling, mitochondrial injury and chromatin condensation in irregular bodies, as well as other subcellular features indicating apoptosis, necrosis, autophagy and excitotoxicity in the CA1, CA2-3 and DG, as revealed by TEM. At P14, P21 and P60, both groups showed small numbers of TUNEL-positive and FJB-positive cells. Stereological analysis at P2, P14, P21 and P60 revealed a lack of significant differences in cleaved caspase-3 IHC between anoxic and control subjects. These results suggest that the type of hippocampal cell death following neonatal anoxia is likely independent of caspase-3 activation. Neonatal anoxia induced deficits in acquisition and performance of spatial reference memory in the Morris water maze task. Compared to control subjects, anoxic animals exhibited increased latencies and path lengths to reach the platform, as well as decreased searching specifically for the platform location. In contrast, no significant differences were observed for swimming speeds and frequency within the target quadrant. Together, these behavioral results indicate that the poorer performance by anoxic subjects is related to spatial memory deficits and not to sensory or motor deficits. Therefore, this model of neonatal anoxia in rats induces hippocampal changes that result in cell losses and impaired hippocampal function, and these changes are likely related to spatial memory deficits in adulthood.

Evaluation of the effects of chronic intoxication with inorganic mercury on memory and motor control in rats

The aims of this study were to evaluate whether chronic intoxication with mercury chloride (HgCl₂), in a low concentration over a long time, can be deposited in the central nervous tissue and to determine if this exposure induces motor and cognitive impairments. Twenty animals were intoxicated for 45 days at a dose of 0.375 mg/kg/day. After this period, the animals underwent a battery of behavioral tests, in a sequence of open field, social recognition, elevated T maze and rotarod tests. They were then sacrificed, their brains collected and the motor cortex and hippocampus dissected for quantification of mercury deposited. This study demonstrates that long-term chronic HgCl₂ intoxication in rats promotes functional damage. Exposure to HgCl₂ induced anxiety-related responses, short- and long-term memory impairments and motor deficits. Additionally, HgCl₂ accumulated in both the hippocampus and cortex of the brain with a higher affinity for the cortex.

Chronic ethanol exposure during adolescence in rats induces motor impairments and cerebral cortex damage associated with oxidative stress

Binge drinking is common among adolescents, and this type of ethanol exposure may lead to long-term nervous system damage. In the current study, we evaluated motor performance and tissue alterations in the cerebral cortex of rats subjected to intermittent intoxication with ethanol from adolescence to adulthood. Adolescent male Wistar rats (35 days old) were treated with distilled water or ethanol (6.5 g/kg/day, 22.5% w/v) during 55 days by gavage to complete 90 days of age. The open field, inclined plane and the rotarod tests were used to assess the spontaneous locomotor activity and motor coordination performance in adult animals. Following completion of behavioral tests, half of animals were submitted to immunohistochemical evaluation of NeuN (marker of neuronal bodies), GFAP (a marker of astrocytes) and Iba1 (microglia marker) in the cerebral cortex while the other half of the animals were subjected to analysis of oxidative stress markers by biochemical assays. Chronic ethanol intoxication in rats from adolescence to adulthood induced significant motor deficits including impaired spontaneous locomotion, coordination and muscle strength. These behavioral impairments were accompanied by marked changes in all cellular populations evaluated as well as increased levels of nitrite and lipid peroxidation in the cerebral cortex. These findings indicate that continuous ethanol intoxication from adolescence to adulthood is able to provide neurobehavioral and neurodegenerative damage to cerebral cortex.

Antioxidant strategies and respiratory disease of the preterm newborn: an update

Preterm newborns are challenged by an excessive oxidative burden, as a result of several perinatal stimuli, as intrauterine infections, resuscitation, mechanical ventilation, and postnatal complications, in the presence of immature antioxidant capacities. "Oxygen radical disease of neonatology" comprises a wide range of conditions sharing a common pathway of pathogenesis and includes bronchopulmonary dysplasia (BPD) and other main complications of prematurity. Antioxidant strategies may be beneficial in the prevention and treatment of oxidative stress- (OS-) related lung disease of the preterm newborn. Endotracheal supplementation or lung-targeted overexpression of superoxide dismutase was proved to reduce lung damage in several models; however, the supplementation in preterm newborn failed to reduce the risk of BPD, although long-term respiratory outcomes were improved. Also melatonin administration to small cohorts of preterm newborns suggested beneficial effects on lung OS. The possibility to identify single nucleotide polymorphism affecting the risk of BPD may help to identify specific populations with particularly high risk of OS-related diseases and may pose the basis for individually targeted treatments. Finally, surfactant replacement may lead to local anti-inflammatory and antioxidant effects, thanks to specific enzymatic and nonenzymatic antioxidants naturally present in animal surfactants.