Induced Brain Damage Research Articles

A Clinical Support System for Brain Tumor Classification Using Soft Computing Techniques.

A brain tumor is an accumulation of abnormal cells in human brain. As tumor increases in size, it induces brain damage. Hence it is essential to diagnose the type of brain tumor. The effective modality used for brain tumor diagnose is MRI because of its remarkable image resolution, the speed of acquisition, and high safety profile for patients. The analysis of brain MRI is an important part of patient care and decision. Hence in the proposed Clinical Support System, the brain MRI image is preprocessed using Genetic Optimized Median Filter followed by brain tumor region segmentation using Hierarchical Fuzzy Clustering Algorithm. The features of the tumor region are extracted through GLCM feature extraction method. Lion Optimized Boosting Support Vector machine model is used for further classification of tumor by Brain Tumor Image Segmentation (BraTS) dataset. Hence the proposed clinical support system provides an integrated model for Detection and classification of brain tumor which assists the doctors in appropriate evaluation of tumor.

Glycine Exhibits Neuroprotective Effects in Ischemic Stroke in Rats through the Inhibition of M1 Microglial Polarization via the NF-κB p65/Hif-1α Signaling Pathway.

Glycine is a simple nonessential amino acid known to have neuroprotective properties. Treatment with glycine results in reduced infarct volume of the brain, neurologic function scores, and neuronal and microglial death in ischemic stroke injury. Neuroinflammation has been considered a major contributor to cerebral ischemia-induced brain damage. However, the role of glycine in neuroinflammation following ischemic stroke is unclear. The present study aimed to determine whether neuroinflammation is involved in the neuroprotective effects of glycine in cerebral ischemia injury. Ischemic stroke promotes M1 microglial polarization. Interestingly, we found that the injection of glycine in rats after injury can inhibit ischemia-induced inflammation and promote M2 microglial polarization in vivo (Sprague-Dawley rats) and in vitro (cortical microglia and BV-2 cells). We show that glycine suppresses Hif-1α by inhibiting the upregulation of NF-κB p65 after ischemia-reperfusion injury, resulting in the inhibition of proinflammatory activity. The activation of AKT mediates the inhibition of NF-κB p65/Hif-1α signaling by glycine. Moreover, we confirm that glycine-regulated AKT activation is mediated by the inhibition of PTEN in a PTEN depletion cell line, U251 cells. Glycine modulates microglial polarization after ischemic stroke, which indirectly inhibits ischemia-induced neuronal death and functional recovery. Taken together, our findings provide a new understanding of glycine in neuroprotection by inhibiting M1 microglial polarization and promoting anti-inflammation by suppressing NF-κB p65/Hif-1α signaling.

Comprehensive analysis of differentially expressed profiles of long non-coding RNAs and messenger RNAs in kaolin-induced hydrocephalus

BackgroundsThe pathophysiology of hydrocephalus induced brain damage remains unclear. Long non-coding RNAs (lncRNAs) have been demonstrated to be implicated in many central nervous system diseases. However, the roles of lncRNAs in hydrocephalus injury are poorly understood. MethodsThe present study depicted the expression profiles of lncRNAs and messenger RNAs (mRNAs) in C57BL/6 mice with kaolin-induced hydrocephalus and saline controls using high-throughput RNA sequencing. Afterward, Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to identify potential targets that correlated with hydrocephalus. In addition, co-expression networks and cis- and trans-regulation were predicted using bioinformatics methods. Finally, representative lncRNAs and mRNAs were further validation using quantitative real-time polymerase chain reaction. ResultsA total of 1575 lncRNAs and 1168 mRNAs were differentially expressed (DE) in hydrocephalus. GO and KEGG analyses indicated several immune and inflammatory response-associated pathways may be important in the hydrocephalus. Besides, functional enrichment analysis based on co-expression network showed several similar pathways, such as chemokine signaling pathway, phagosome, MAPK signaling pathway and complement and coagulation cascade. Cis-regulation prediction revealed 5 novel lncRNAs might regulate their nearby coding genes, and trans-regulation revealed several lncRNAs participate in pathways regulated by transcription factors, including BPTF, FOXM1, NR5A2, P2RX5, and NR6A1. ConclusionsIn conclusion, our results provide candidate genes involved in hydrocephalus and suggest a new perspective on the modulation of lncRNAs in hydrocephalus.

Starting ketamine for neuroprotection earlier than its current use as an anesthetic/antiepileptic drug late in refractory status epilepticus

Ketamine is currently being used as an anesthetic/antiepileptic drug in refractory status epilepticus. To validate its use, 2 clinical trials are recruiting patients. However, preclinical studies of its use in chemically induced status epilepticus in rodents have shown that it is remarkably neuroprotective, through N-methyl-d-aspartate-receptor blockade, even when given after the onset of status epilepticus. Human studies have shown that status epilepticus-induced brain damage can be caused by a glutamate analogue and that it occurs in the same brain regions as in the animal studies. We therefore propose that ketamine be started early in the course of human status epilepticus as a neuroprotectant and that it be continued until epileptic discharges are eliminated. Using it as an anesthetic/antiepileptic drug late in the course of refractory status epilepticus only ensures that it is given after widespread brain damage has occurred.

Umbilical cord mesenchymal stem cells and umbilical cord blood mononuclear cells improve neonatal rat memory after hypoxia-ischemia

Current treatment options for hypoxic-ischemic encephalopathy (HIE) are limited. Human umbilical cord mesenchymal stem cells (UC-MSCs) and cord blood mononuclear cells (CB-MNCs) offer great potential for the treatment of many neurological diseases. The aim of the present study was to identify which cell type is more effective for the treatment of HIE. PKH26-labeled UC-MSCs and CB-MNCs were transplanted into rats with hypoxia-ischemia (HI)-induced brain damage. Apoptotic cell numbers in the brain, as labeled by TUNEL, were assessed. Myelination and gliosis were investigated using myelin basic protein and glial fibrillary acidic protein immunohistochemistry, respectively. The Morris water maze was used to assess animal learning abilities. Our data show that transplantation of UC-MSCs or CB-MNCs after HI reduced astrogliosis, prevented neuronal loss in the striatum, and markedly improved functional brain outcomes after a 28-day recovery period. Moreover, treatment with CB-MNCs increased the proportion of mature oligodendrocytes and improved myelination in cortical areas. Both UC-MSCs and CB-MNCs may result in the recovery of neurological function in HI rats. Based on our data, UC-MSCs and UCB-MNCs may be particularly effective stem cell subsets for treatment of neonatal HIE.

Pharmacognostic Study, Phytochemical Screening and Neuroprotective Activity of Methanolic extract of Gynandropsis gynandra against Transient Global Ischemia induced brain damage in rats

Gynandropsis gynandra is found to contain flavonoids which are proven to be potent neuroprotective agents which could cross blood brain barrier easily and treat neurotoxicity. Neurons get damaged easily because of our current lifestyle which includes usage of gadgets, smartphones etc causing memory loss, degraded cognitive thinking and other disorders like stroke. The best way to treat or prevent this is intake of flavonoids which have protective effect. The aim of the work was to assess protective effect of methanolic extract of whole herb of Gynandropsis gynandra against cerebral ischemia induced brain damage in albino wister rats. Pharmacognostic studies and phytochemical screening was carried out using standard methods. Cerebral ischemia was induced by occluding carotid artery using nylon thread followed by reperfusion. Animals were sacrificed and immediately brains were isolated and analysed for various biochemical parameter estimation, brain infarct area and histopathological studies. Biochemical estimations were measured and results were expressed in terms of Mean ± SEM by using ANNOVA software. Pharmacognostic study gave relevant information about ash values and Extractive values. Methonolic extract of Gynandropsis gynandra have proven to have protective effect. Of all the three doses, 300mg/kg dose of the drug have shown maximum protective effect when compared to other two doses.

Carbon monoxide poisoning–induced delayed encephalopathy accompanies decreased microglial cell numbers: Distinctive pathophysiological features from hypoxemia–induced brain damage

Carbon monoxide (CO) causes not only acute fatal poisoning but also may cause a delayed neurologic syndrome called delayed encephalopathy (DE), which occasionally occurs after an interval of several days to several weeks post-exposure. However, the mechanisms of DE have not been fully elucidated. This study aimed to clarify the pathophysiology of CO–induced DE and its distinctive features compared with hypoxemic hypoxia. Rats were randomly assigned to three groups; the air group, the CO group (exposed to CO), and the low O2 group (exposed to low concentration of O2). Impairment of memory function was observed only in the CO group. The hippocampus tissues were collected and analyzed for assessment of CO–induced changes and microglial reaction. Demyelination was observed only in the CO group and it was more severe and persisted longer than that observed in the low O2 group. Moreover, in the CO group, decreased in microglial cell numbers were observed using flow cytometry, and microglia with detached branches were observed were observed using immunohistochemistry. Conversely, microglial cells with shortened branches and enlarged somata were observed in the low O2 group. Furthermore, mRNAs encoding several neurotrophic factors expressed by microglia were decreased in the CO group but were increased in the low O2 group. Thus, CO–induced DE displayed distinctive pathological features from those of simple hypoxic insults: prolonged demyelination accompanying a significant decrease in microglial cells. Decreased neurotrophic factor expression by microglial cells may be one of the causes of CO–induced DE.

Oxytocin receptor agonist reduces perinatal brain damage by targeting microglia.

Prematurity and fetal growth restriction (FGR) are frequent conditions associated with adverse neurocognitive outcomes. We have previously identified early deregulation of genes controlling neuroinflammation as a putative mechanism linking FGR and abnormal trajectory of the developing brain. While the oxytocin system was also found to be impaired following adverse perinatal events, its role in the modulation of neuroinflammation in the developing brain is still unknown. We used a double-hit rat model of perinatal brain injury induced by gestational low protein diet (LPD) and potentiated by postnatal injections of subliminal doses of interleukin-1β (IL1β) and a zebrafish model of neuroinflammation. Effects of the treatment with carbetocin, a selective, long lasting, and brain diffusible oxytocin receptor agonist, have been assessed using a combination of histological, molecular, and functional tools in vivo and in vitro. In the double-hit model, white matter inflammation, deficient myelination, and behavioral deficits have been observed and the oxytocin system was impaired. Early postnatal supplementation with carbetocin alleviated microglial activation at both transcriptional and cellular levels and provided long-term neuroprotection. The central anti-inflammatory effects of carbetocin have been shown in vivo in rat pups and in a zebrafish model of early-life neuroinflammation and reproduced in vitro on stimulated sorted primary microglial cell cultures from rats subjected to LPD. Carbetocin treatment was associated with beneficial effects on myelination, long-term intrinsic brain connectivity and behavior. Targeting oxytocin signaling in the developing brain may be an effective approach to prevent neuroinflammation - induced brain damage of perinatal origin.

MiR-181b regulates ER stress induced neuron death through targeting Heat Shock Protein A5 following intracerebral haemorrhage

Endoplasmic reticulum (ER) stress acts as a protein folding and contributes to neuronal damage and neurological deterioration following intracerebral hemorrhage (ICH). Heat Shock Protein A5 (HSPA5) serves as an essential regulator of the endoplasmic reticulum (ER) stress response. However, the specific mechanism has not been will identified. Primary cortical neurons from C57BL/6 mice were subjected to erythrocyte lysates. Cell viability, microRNA and HSPA5 levels, and ER stress was detected. The interaction between microRNA and the target HSPA5 was identified by dual luciferase reporter gene assay. In addition, inflammatory cytokines, brain edema, and neurological functions in ICH mice were also assessed. Erythrocyte lysates induced ER stress and neuron damage, downregulated miR-181b and upregulated HSPA5 levels. MiR-181b suppressed HSPA5 expression by directly binding its 3′-untranslated region. Correspondingly, our data demonstrated that overexpression of miR-181b attenuated erythrocyte lysates induced neuronal necrosis and apoptosis. In vivo, downregulated miR-181b increased the HSPA5 level, along with significant elevations of pro-inflammatory cytokines, brain edema, and neurological injury following ICH. HSPA5 pathway plays an important role in ER stress induced brain damage following ICH. In addition, miR-181b has neuroprotective effects that alleviates neurological injury and represents a promising therapeutic strategy in ICH.

Neuroprotection against CCl4 induced brain damage with crocin in Wistar rats

ABSTRACT Owing to its lipophilic property, carbon tetrachloride (CCl4) is rapidly absorbed by both the liver and brain. We investigated the protective effects of crocin against brain damage caused by CCl4. Fifty rats were divided into five groups of ten: control, corn oil, crocin, CCl4 and CCl4 + crocin. CCl4 administration decreased glutathione (GSH) and total antioxidant status (TAS) levels, and catalase (CAT) activity, while significant increases were observed in malondialdehyde (MDA) and total oxidant status (TOS) levels and superoxide dismutase (SOD) activity. The cerebral cortex nuclear lamina developed a spongy appearance, neuronal degeneration was observed in the hippocampus, and heterochromatic and pyknotic neurons with increased cytoplasmic eosinophilia were observed in the hippocampus after CCl4 treatment. Because crocin exhibits strong antioxidant properties, crocin treatment increased GSH and TAS levels and CAT activities, and decreased MDA and TOS levels and SOD activity; significant improvements also were observed in histologic architecture. We found that crocin administration nearly eliminated CCl4 induced brain damage by preventing oxidative stress.

Effects of gestational exercise on hyperoxia-induced brain damage in the newborn

Aim: Preterm infants encounter hyperoxia relatively early on as they leave the intrauterine environment earlier than expected, while also being exposed to a higher level of hyperoxic stress due to insufficiencies in their antioxidant defense mechanisms. With that in mind, we investigate whether running exercises performed during pregnancy can contribute to the development of tolerance to neonatal hyperoxic brain damage. Method: While two female rats maintained a sedentary pregnancy, one female rat performed the mandatory running exercise for 30 minutes for five days a week throughout the pregnancy. Following delivery, the sedentary rats and the exercised rat were kept together with their offspring for five days at oxygen concentrations above 80 percent in order to induce brain damage. The offspring were sacrificed on postnatal Day 7 and brain/body ratio measurements were obtained. Results: The brain/body ratios in the control, hyperoxia and exercise-hyperoxia groups were found to be median (IQR) 0.074(0.68-0.77), 0.065(0.06-0.067) and 0.064(0.060-0.068), respectively. The brain/body ratios of the offspring of the mothers in the hyperoxia group were found to be significantly lower than the control group (p=0.002), irrespective of exercise (p=0.007). No statistically significant difference was noted between the offspring of the sedentary and the exercised mothers in the hyperoxia group (p=0.94). Conclusion: Hyperoxia was found to result in lower brain mass relative to total body mass. This finding, which indicates the presence of microcephaly, reflects the negative effects of hyperoxia on brain development. Contrary to expectations, exercises performed during pregnancy had no significant effect on the brain/body weight ratio of the offspring.

Perindopril ameliorates lipopolysaccharide-induced brain injury through modulation of angiotensin-II/angiotensin-1-7 and related signaling pathways

Localized tissue renin-angiotensin system (RAS) is an interesting pathway of organ damage. Here, the effect of the brain-penetrating angiotensin converting enzyme (ACE) inhibitor perindopril was studied on lipopolysaccharide (LPS)-induced brain damage, with and without exogenous angiotensin (Ang)-II administration. Animals were divided into 6 groups; a normal control group, an LPS control group (LPS, 3 mg/kg, i.p., single dose), two treatment groups receiving perindopril (1 and 2 mg/kg/day, i.p.) for 7 days before LPS administration, and two Ang-II/perindopril/LPS groups receiving perindopril and LPS, followed by a single dose of Ang-II solution (5 µl, i.c.v.). Brain tissue Ang-II, Ang-1-7, and NADPH oxidase were estimated using ELISA technique. Nuclear factor kappa-B (NF-ƙB-p65) was estimated using real time PCR technique, while phosphorylated NF-ƙB-p65 (p-NF-ƙB-p65), phosphorylated and non-phosphorylated protein kinase B (p-Akt and Akt) and phosphorylated inhibitor of kappa-B (p-IƙBa) were estimated by western blot analysis. Malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), glutathione-S-transferase (GST), catalase, nitrite and myloperoxidase (MPO) were estimated colorimetrically. Brain tissue inducible and endothelial nitric oxide synthases (iNOS and eNOS) were estimated immunohistochemically, confirmed by a histopathological study. LPS-intoxicated rats showed significantly elevated Ang-II, NADPH oxidase, NF-ƙB-p65, p-NF-ƙB-p65, p-IƙBa, p-Akt, Akt, p-Akt/Akt ratio, MDA, nitrite, MPO and iNOS levels, coupled with significantly suppressed Ang-1-7, GSH, SOD, GST, catalase, and eNOS levels, which were all corrected by pre-treatment with perindopril in both doses by varying degrees. Exogenous Ang-II significantly ameliorated the protective effects of perindopril. Conclusively, perindopril ameliorates LPS-induced brain damage through modulation of RAS, iNOS/eNOS, p-Akt/Akt and NF-ƙB signaling pathways.

Brain microglia activation induced by intracranial administration of oligonucleotides and its pharmacological modulation.

Oligonucleotide overloading results in type I interferonopathies such as the Aicardi-Goutiéres Syndrome, a progressive encephalopathy determined by an immune response against endogenous DNA/RNA molecules. No therapy targeting pathogenic mechanisms is available for affected patients. Accordingly, we set up an in vitro/in vivo experimental model aimed at reproducing the pathogenic mechanisms of type I interferonopathies, in order to develop an effective pharmacological modulation and toxicological alterations caused by intracranial delivery of encapsulated CpG. The in vitro model used Aicardi-Goutiéres Syndrome immortalized lymphocytes activated by interferon I and co-cultured with human astrocytes; lymphocyte neurotoxicity was attenuated by the calcineurin-inhibitor Tacrolimus and by the anti-interferon monoclonal antibody Sifalimumab. The in vivo model was set up in mice by subcutaneous injection of encapsulated CpG oligonucleotides; the immune-stimulating activity was demonstrated by cytometric analysis in the spleen. To mime pathogenesis of type I interferonopathies in the central nervous system, CpG oligonucleotides were administered intracranially in mice. In the brain, CpG overload induced a rapid activation of macrophage-like microglial cells and focal accumulation mononuclear cells. The subcutaneous administration of Tacrolimus and, more potently, Sifalimumab attenuated CpG-induced brain alterations. These findings shed light on molecular mechanisms triggered by oligonucleotides to induce brain damage. Monoclonal antibodies inhibiting interferon seem a promising therapeutic strategy to protect brain in type I interferonopathies.

Octadecylpropyl Sulfamide Reduces Neurodegeneration and Restores the Memory Deficits Induced by Hypoxia-Ischemia in Mice.

The PPAR-α agonist, oleoylethanolamide (OEA) has neuroprotective properties in stroke models. However, its rapid degradation represents a limitation for an effective therapeutic approach. In this study, we evaluated the effects of a stable OEA-modeled compound, octadecylpropyl sulfamide (SUL) on the cognitive, behavioral, cellular and molecular alterations associated with hypoxia-ischemia (HI) in mice. Mice subjected to HI were treated with the PPAR-α antagonist GW6471 (GW) (1 mg/kg) followed 15 min later by SUL (3 and 10 mg/kg). Behavioral, motor, and cognitive tests were carried out 24 h and 7 days after the HI. The levels of microglia, reactive astrocytes and neuronal nuclei were studied using immunofluorescence, and the expression of genes related to the N-acyl-ethanolamides/endocannabinoid signaling systems was determined by qRT-PCR at the end of the experimental sequence. HI induced brain damage in the ipsilateral hippocampus and cortex, which lead to severe memory impairments, and motor coordination deficits. Significant neuronal loss, increased microglia and reactive astrocytes, and compensatory changes in genes associated with the inflammation/immune and endocannabinoid systems were observed in these brain structures of lesioned mice. SUL reversed the memory and motor deficits, decreased the overexpression of microglia and astrocytes, and reduced neurodegeneration induced by HI. Cnr1 and Cnr2 gene expression was modulated by SUL in both sham and HI mice, while Pparα and Faah expression was regulated in HI mice. GW completely blocked the beneficial actions of SUL. These findings suggest that treatment with SUL reduces brain damage and the associated motor and memory deficits induced by HI probably by normalizing the changes in neuroinflammation/immune system mediators.

Pyridoxine dependent epilepsy: Is late onset a predictor for favorable outcome?

In pyridoxine dependent epilepsy (PDE), patients usually present with neonatal seizures. A small subgroup is characterized by late-onset beyond 2 months of age. We aim to analyze the observation of relatively good cognitive outcome in this subgroup of late-onset PDE patients. We retrospectively analyzed data from four metabolically and genetically confirmed late-onset patients with PDE due to antiquitin (ALDH7A1) deficiency. Data were analyzed regarding ALDH7A1 mutations, alpha-Aminoadipic semialdehyde (α-AASA) and pipecolic acid (PA) levels, medication during pregnancy, delivery, treatment delay, amount of seizures, pyridoxine dose, adjuvant therapy and findings on brain MRI. Results showed that three patients had relatively good outcome (IQ 80-97), while one patient did not undergo formal testing and was considered mildly delayed. We were unable to find a clear association between the above-mentioned variables and cognitive outcome, although a less severe genotype may be present in three patients, and maternal medication could be accountable for better outcome in two patients. We suggest that favorable outcome in late onset PDE might be explained by a combination of factors. A yet unknown protective factor, different genetic variations, functional variation and secondarily variation in treatment regimens and absence of neonatal seizure induced brain damage.

Blockade of the swelling-induced chloride current attenuates the mouse neonatal hypoxic-ischemic brain injury in vivo.

Activation of swelling-induced Cl- current (ICl,swell) during neonatal hypoxia-ischemia (HI) may induce brain damage. Hypoxic-ischemic brain injury causes chronic neurological morbidity in neonates as well as acute mortality. In this study, we investigated the role of ICl,swell in hypoxic-ischemic brain injury using a selective blocker, 4-(2-butyl-6,7-dichloro-2-cyclopentylindan-1-on-5-yl) oxybutyric acid (DCPIB). In primary cultured cortical neurons perfusion of a 30% hypotonic solution activated ICl,swell, which was completely blocked by the application of DCPIB (10 μmol/L). The role of ICl,swell in neonatal hypoxic-ischemic brain injury in vivo was evaluated in a modified neonatal hypoxic-ischemic brain injury model. Before receiving the ischemic insult, the mouse pups were injected with DCPIB (10 mg/kg, ip). We found that pretreatment with DCPIB significantly reduced the brain damage assessed using TTC staining, Nissl staining and whole brain imaging, and improved the sensorimotor and vestibular recovery outcomes evaluated in neurobehavioural tests (i.e. geotaxis reflex, and cliff avoidance reflex). These results show that DCPIB has neuroprotective effects on neonatal hypoxic-ischemic brain injury, and that the ICl,swell may serve as a therapeutic target for treatment of hypoxic-ischemic encephalopathy.

Characterization of uniaxial high-speed stretch as an in vitro model of mild traumatic brain injury on the blood-brain barrier

Traumatic brain injury (TBI) occurs when external mechanical forces induce brain damage as result of impact, penetration or rapid acceleration/deceleration that causes deformation of brain tissue. Depending on its severity, TBI can be classified as mild, moderate or severe and can lead to blood-brain barrier (BBB) dysfunction. In the present study, we evaluated the effects of uniaxial high-speed stretch (HSS) at 0, 5, 10 and 15% on a pure culture of primary rat brain endothelial cells as an in vitro model of TBI to the BBB. LDH release, viability and apoptosis analysis, expression of tight junction proteins and endothelial permeability were evaluated 24 h after a single stretch episode. HSS slightly increased cell death and apoptosis at 10 and 15%, while LDH release was increased only at 15% stretch. Occludin expression was increased at 10% stretch, while claudin-5 expression was increased at 5% stretch, which also decreased the endothelial permeability. In summary, 15% HSS induced low levels of cell death, consistent with mild TBI and very low percentages of HSS (5%) enhanced the BBB properties, promoting the formation of a stronger barrier. These data support the use of 15% HSS as valuable tool in the study of mild TBI to the BBB in vitro.

Circular RNA Expression in the Brain of a Neonatal Rat Model of Periventricular White Matter Damage

Background/Aims: Periventricular white matter damage (PWMD) is the predominant neurologic lesion in preterm infants who survive brain injury. In this study, we assessed the global changes in and characteristics of the transcriptome of circular RNAs (circRNAs) in the brain tissues of rats with PWMD. Methods: We compared the expression profiles of circRNAs in brain samples from three rats with PWMD and three paired control tissues using deep RNA sequencing. Bioinformatics analysis was applied to investigate these differentially expressed circRNAs, and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis was performed to confirm the results. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to predict associated cell signaling pathways and functions. Network analysis was performed to predict circRNAs-microRNAs, and target genes related to PWMD. Results: A total of 2151 more reliable circRNAs were dysregulated in the brain tissues of rats with PWMD, indicating a potential role in the condition. Of the 98 circRNAs significantly differentially expressed in rat brains with PWMD (P< 0.05), 52 were significantly over-expressed and 46 were significantly under-expressed. The expression profiles of seven of 10 randomly selected circRNAs were confirmed by qRT-PCR analysis. The glutamatergic synapse pathway and the VEGF signaling pathway, both associated with hypoxia/ischemia induced brain damage, were inriched. Relationship between miRNA (rno-miR-433-3p and rno-miR-206-3p) and HIF-1α were evident and potential associations between chr6: 48820833|48857932 and their target genes (rno-miR-433-3p and rno-miR-206-3p) were identified. Conclusion: The distinct expression patterns of circRNAs in the brain tissues of rats with PWMD suggest that circRNAs actively respond to hypoxia-ischemia. These findings could assist the development of novel diagnostic and therapeutic targets for PWMD therapy.

Delayed neurochemical effects of prenatal exposure to MeHg in the cerebellum of developing rats

Human fetuses and neonates are particularly vulnerable to methylmercury (MeHg)-induced brain damage and are sensitive even to low exposure levels. Previous work of our group evidence that prenatal exposure to MeHg causes cognitive and behavioral alterations and disrupt hippocampus signaling. The current study aimed to investigate the effect of gestational exposure of rats to MeHg at low doses (1 or 2 mg/kg) on parameters of redox imbalance and key signaling pathways in the cerebellum of their offspring. Pregnant females received MeHg (treated group) or 0.9% saline water (control group) by gavage in alternated days from gestational day 5 (GD5) until parturition and analyzes were proceed in the cerebellum of 30-day-old pups. We found increased lipid peroxidation and protein carbonylation levels as well as decreased SH content in pups prenatally exposed to 2 mg/kg MeHg. In addition, misregulated SOD/catalase activities supported imbalanced redox equilibrium. We found decreased GSK3β(Ser9) phosphorylation, suggesting activation of this enzyme and dephosphorylation/inhibition of ERK1/2 and JNK pathways. Increased PKAα catalytic subunit could be upstream of hyperphosphorylated c-Raf(Ser259) and downregulated MAPK pathway. In addition, we found raised levels of the Ca2+-dependent protein phosphatase 2 B (PP2B). We also found preserved immunohistochemical staining for both glial fibrillary acidic protein (GFAP) and NeuN in MeHg-exposed pups. Western blot analysis showed unaltered levels of BAX/BCL-XL, BAD/BCL-2 and active caspase 3. Together, these findings support absence of reactive astrocytes, neuronal damage and apoptotic cell death in the cerebellum of MeHg treated pups. The present study provides evidence that prenatal exposure to MeHg leads to later redox imbalance and disrupted signaling mechanisms in the cerebellum of 30-day-old pups potentially predisposing them to long-lasting neurological impairments in CNS.

Ameliorative role of genistein against age-dependent chronic arsenic toxicity in murine brains via the regulation of oxidative stress and inflammatory signaling cascades

Brain is highly prone to oxidative damage due to its huge lipid content and extensive energy requirements. Exogenous insult in brain via oxidative injury can lead to severe pathophysiological conditions. Age-dependent deterioration of normal brain functions is also noteworthy. Genistein, a polyphenolic isoflavonoid, obtained from the soy plant, is well known to protect against several diseased conditions. Here, in this study chronic brain toxicity model was developed using oral administration of arsenic for 90 days in adult and aged murines. We observed that intraperitoneal administration of genistein improved the arsenic induced behavioral abnormalities in the rats. It was also evident from the histopathological studies that the extent of tissue damage due to arsenic exposure was more in aged rats compared to the adults. Evaluation of different stress markers, intracellular ROS level and mitochondrial membrane potential revealed the involvement of oxidative stress and mitochondrial dysfunction in inducing brain damage in arsenic exposed murines. It was observed that genistein can significantly ameliorate the stressed condition in both the animal groups but the protective effect of genistein was more significant in the adult animals. The underlying signalling mechanism behind the cytotoxicity of arsenic was investigated and revealed that genistein exhibited neuroprotection significantly by modulating the JNK3 mediated apoptosis, ERK1/2 mediated autophagy and TNFα associated inflammatory pathways. Overall study infers that genistein has significant ameliorative effect of against age-dependent cytotoxicity of arsenic in murine brains.