Number Of Damaged Neurons Research Articles

Curcumin alleviates Alzheimer’s disease by inhibiting inflammatory response, oxidative stress and activating the AMPK pathway

BackgroundAlzheimer’s disease (AD) is a common degenerative brain disorder with limited therapeutic options. Curcumin (Cur) exhibits neuroprotective function in many diseases. We aimed to explore the role and mechanism of Cur in AD. Materials and MethodsFirstly, we established AD mice by injecting amyloid-β1–42 (Aβ1–42) solution into the hippocampus. Then, the AD mice received 150 mg/kg/d Cur for 10 consecutive days. The Morris water maze test was conducted to evaluate the cognitive function of the mice by hidden platform training and probe trials. To assess the spatial memory of the mice, spontaneous alternation behavior, the number of crossing the novel arm and the time spent in the novel arm during the Y-maze test was recorded. Hematoxylin and eosin (H&E) staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNAL) assay were performed to assess the pathological damage and apoptosis of brain tissues. The number of damaged neurons was inspected by Nissl staining. Immunohistochemical staining was then performed to detect Aβ1–42 deposition. The levels of tumor necrosis factor-α (TNF-a), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in serum and hippocampus, the contents of super oxide dismutase (SOD) and malondialdehyde (MDA) in brain tissues were assessed by enzyme-linked immunosorbent assay (ELISA). Additionally, B-cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), RelA (p65) protein expressions and Adenosine 5′-monophosphate-activated protein kinase (AMPK) phosphorylation were tested using Western blot. ResultsCur not only improved cognitive function and spatial memory, but also alleviated the pathological damage and apoptosis of brain tissues for AD mice. Meanwhile, upon Cur treatment, the number of damaged neurons in AD mice was decreased, the level of Aβ1–42 in AD mice was significantly decreased. Furthermore, the AD mice treated with Cur exhibited lower TNF-a, IL-6, IL-1β and MDA levels and a higher SOD content. Besides, Cur also downregulated p65 expression and upregulated AMPK phosphorylation. ConclusionCur may improve AD via suppressing the inflammatory response, oxidative stress and activating the AMPK pathway, suggesting that Cur may be a potential drug for AD.

Downregulation of SIRT1, SIRT3, and IGF-1 in ApoE-deficient mice exacerbates neuronal damage induced by chronic cerebral hypoperfusion

Chronic cerebral hypoperfusion is a widespread pathological condition caused by chronically reduced cerebral blood flow leading to brain damage, but the specific molecular mechanisms that regulate these phenomena remain poorly understood. In this study, we investigated brain damage and neuronal DNA injury in a vulnerable region of the brain, the hippocampus, as well as the involvement of apolipoprotein E (ApoE), sirtuins of 1 (SIRT1) and 3 (SIRT3) types and insulin-like growth factor 1 (IGF-1) in pathogenetic mechanisms in mice with chronic cerebral hypoperfusion caused by the permanent occlusion of the left unilateral common carotid artery. Male C57/6j (C57, wild type) and ApoE(-/-) mice were divided into four experimental groups (10 mice per group): sham-operated С57, С57 with chronic cerebral hypoperfusion, sham-operated ApoE(-/-) mice, ApoE(-/-) mice with chronic cerebral hypoperfusion. Our results showed that the number of damaged neurons in the hippocampus at 8 weeks after surgical manipulation increased in both groups of mice with chronic cerebral hypoperfusion, with more pronounced rates in ApoE(-/-) mice than in C57 mice. However, ApoE deficiency in moderate chronic cerebral hypoperfusion was accompanied by a higher level of undamaged DNA (class 0) and a low level of maximally damaged DNA (class 4) in brain cell nuclei in contrast to group C57. In ApoE-deficient mice, reduced expression of SIRT1, SIRT3, and IGF-1 was found. In chronic cerebral hypoperfusion, expression of sirtuins was preserved, but IGF-1 expression was significantly reduced in ApoE(-/-) mice in comparison to C57. The obtained results indicate that ApoE deficiency leads to downregulation of SIRT1, SIRT3 and IGF-1 in the brain; this lack of cytoprotection is enhanced in chronic cerebral hypoperfusion and may participate in the mechanisms of neuronal damage.

Esketamine is neuroprotective against traumatic brain injury through its modulation of autophagy and oxidative stress via AMPK/mTOR-dependent TFEB nuclear translocation

Recent clinical studies highlight the neuroprotective effects of esketamine, but its benefits following traumatic brain injury (TBI) have not been defined. Here, we investigated the effects of esketamine following TBI and its associated neuroprotection mechanisms. In our study, controlled cortical impact injury on mice was utilized to induce the TBI model in vivo. TBI mice were randomized to receive vehicle or esketamine at 2 h post-injury for 7 consecutive days. Neurological deficits and brain water content in mice were detected, respectively. Cortical tissues surrounding focal trauma were obtained for Nissl staining, immunofluorescence, immunohistochemistry, and ELISA assay. In vitro, esketamine were added in culture medium after cortical neuronal cells induced by H2O2 (100μM). After exposed for 12h, neuronal cells were obtained for western blotting, immunofluorescence, ELISA and CO-IP assay. Following administration of 2–8 mg/kg esketamine, we observed that 8 mg/kg esketamine produced no additional recovery of neurological function and ability to alleviate brain edema in TBI mice model, so 4 mg/kg esketamine was selected for subsequent experiments. Additionally, esketamine can effectively reduce TBI-induced oxidative stress, the number of damaged neurons, and the number of TUNEL-positive cells in the cortex of TBI models. Meanwhile, the levels of Beclin 1, LC3 II, and the number of LC3-positive cells in injured cortex were also increased following esketamine exposure. Western blotting and immunofluorescence assays showed that esketamine accelerated the nuclear translocation of TFEB, increased the p-AMPKα level and decreased the p-mTOR level. Similar results including nuclear translocation of TFEB, the increases of autophagy-related markers, and influences of AMPK/mTOR pathway were observed in H2O2-induced cortical neuronal cells; however, BML-275 (AMPK inhibitor) can reverse these effects of esketamine. Furthermore, TFEB silencing not only decreased the Nrf2 level in H2O2-induced cortical neuronal cells, but also alleviated the oxidative stress. Importantly, CO-IP confirmed the interaction between TFEB and Nrf2 in cortical neuronal cells. These findings suggested that esketamine exerts the neuroprotective effects of esketamine in TBI mice model via enhancing autophagy and alleviating oxidative stress; its mechanism involves AMPK/mTOR-dependent TFEB nuclear translocation-induced autophagy and TFEB/Nrf2-induced antioxidant system.

Damage to neurons of the cerebral cortex in acute poisoning with baclofen and its combination with ethanol

BACKGROUND: The number of poisoning with a muscle relaxant baclofen has increased recently. The brain is one of the target organs in baclofen poisoning.
 AIM: To identify and quantify cerebral cortex neuron damage in baclofen and baclofen ethanol poisoning.
 MATERIAL AND METHODS: A histological study of rat cerebral cortex was performed. The controls (n = 5) received neither baclofen nor ethanol. Groups 1 and 3 received baclofen (85 mg/kg), whereas groups 2 and 4 received baclofen (85 mg/kg) and ethanol (7 ml/kg). Groups 1 and 3 were euthanized 4 h after the drug administration, whereas groups 2 and 4 were euthanized after 24 h. Histological sections were stained with hematoxylin and eosin and by the Nissl method and examined by light microscopy (400). The number of damaged neurons was calculated. Statistical processing was performed by the nonparametric MannWhitney method.
 RESULTS: Neurons with reversible and irreversible changes in the controls accounted for 13% and 9%, respectively. At 4 h after baclofen administration, neurons with reversible and irreversible changes accounted for 22% and 21%; 4 h after baclofen and ethanol administration, 24% and 29%; 24 h after baclofen administration, 25% and 37%, respectively. Baclofen and ethanol administration caused an increase in the share of neurons with reversible (27%) and irreversible (41%) changes. The differences between group 3 and the control group were significant, and the difference was significant when group 4 was compared with the control group and group 3.
 CONCLUSION: Understanding the processes in the brain during baclofen and baclofen ethanol administration will allow the provision of medical care to this category of patients more effectively. The signs of brain neuron damage, along with the results of forensic chemical analysis, can be used to establish the immediate cause of death.

Does Intravitreal Dopamine Agonist and Antagonist Administration Have Effects on the Brain? An Experimental Study in Rats.

There might be dopaminergic connections between the retina and the brain. In this context, the study was aimed to investigate the possible interaction between the retina and basal ganglia through the dopaminergic system. In total, 32 healthy rats were randomized into 4 groups: healthy, Sham, dopamine antagonist injected group (risperidone, 0.04 mg/kg intravitreally), and dopamine agonist injected group (apomorphine, 0.4 mg/kg intravitreally). The locomotor activity and Morris water maze tests were applied to all rats twice, before the injection and 28 days after, to detect changes in movement, memory, and attention. Histopathologically, the basal ganglia and hippocampus regions were removed and examined. In the locomotor activity test, a statistical significance was found between the first and last measurement values of the apomorphine group and a decrease in activities and an increase in resting times (P < .05). In the Morris water maze test, a statistical significance was detected between the first and last tests of the control group and the apomorphine groups and showed significantly shorter learning times (P < .05). Histological analyses of the substantia nigra and hippocampus were noteworthy in that the number of damaged neurons in the risperidone group was considerably higher than the other groups. The number of damaged neurons in the apomorphine group was significantly lower than in the healthy group. Intravitreal administration of dopamine agonists and antagonists has given rise to alterations in the cerebral dopaminergic system, leading to changes in locomotor activity and memory and histopathological changes.

Inhibition of gene expression and production of iNOS and TNF-α in experimental model of neurodegenerative disorders stimulated microglia by Soy nano-isoflavone/stem cell-exosomes

The present study evaluated the therapeutic potential of soybean nano-isoflavone extract versus bone marrow mesenchymal stem cells derived extracellular exosomes (BMSCs-EXs) in experimentally induced neurodegenerative diseases in rats (ND). In this study, 36 albino male rats were divided into four groups: Group I (control rats); Group II (induced neurodegenerative disease in rats by intraperitoneal injection of d-galactose (120 mg/kg/day for 2 months); Group III (ND-induced rats treated with nano-isoflavone in doses of 10 mg/kg by oral gavage for 3 months); and Group IV (ND-induced rats treated with a single dose injection of BMSCs-EXs. The effect of BMSCs-EXs was evaluated by cerebral oxidant/antioxidant biomarkers, and mRNA gene expression quantitation for cerebral tumor necrosis factor α (TNF-α), inducible nitric oxide synthase (i-NOS) and GAPDH pathway-encoding genes by real time reverse transcription polymerase chain reaction (RT-PCR) techniques. Then, histopathological examination of the cerebral cortical tissues. Our results showed that BMSC-EXs were successfully isolated and characterized. d-galactose produced a significant rise in the number of damaged neurons, decreased cerebral superoxide dismutase and catalase activities, increased cerebral malondialdehyde levels, downregulated the cerebral TNF-α, and i-NOS pathway-encoding genes. Furthermore, BMSC-EXs and nano-isoflavone treatments repaired damaged cerebral tissue and recovered its function greatly following induction of neurodegenerative disease. Treatment with either MSCs-EXs or nano-isoflavones led to significant improvement in the histological findings, reversed the degenerative effect of d-galactose, and had a favorable therapeutic utility against d- galactose-induced neurodegenerative disease.

Tissue-resident M2 macrophages directly contact primary sensory neurons in the sensory ganglia after nerve injury

BackgroundMacrophages in the peripheral nervous system are key players in the repair of nerve tissue and the development of neuropathic pain due to peripheral nerve injury. However, there is a lack of information on the origin and morphological features of macrophages in sensory ganglia after peripheral nerve injury, unlike those in the brain and spinal cord. We analyzed the origin and morphological features of sensory ganglionic macrophages after nerve ligation or transection using wild-type mice and mice with bone-marrow cell transplants.MethodsAfter protecting the head of C57BL/6J mice with lead caps, they were irradiated and transplanted with bone-marrow-derived cells from GFP transgenic mice. The infraorbital nerve of a branch of the trigeminal nerve of wild-type mice was ligated or the infraorbital nerve of GFP-positive bone-marrow-cell-transplanted mice was transected. After immunostaining the trigeminal ganglion, the structures of the ganglionic macrophages, neurons, and satellite glial cells were analyzed using two-dimensional or three-dimensional images.ResultsThe number of damaged neurons in the trigeminal ganglion increased from day 1 after infraorbital nerve ligation. Ganglionic macrophages proliferated from days 3 to 5. Furthermore, the numbers of macrophages increased from days 3 to 15. Bone-marrow-derived macrophages increased on day 7 after the infraorbital nerve was transected in the trigeminal ganglion of GFP-positive bone-marrow-cell-transplanted mice but most of the ganglionic macrophages were composed of tissue-resident cells. On day 7 after infraorbital nerve ligation, ganglionic macrophages increased in volume, extended their processes between the neurons and satellite glial cells, and contacted these neurons. Most of the ganglionic macrophages showed an M2 phenotype when contact was observed, and little neuronal cell death occurred.ConclusionMost of the macrophages that appear after a nerve injury are tissue-resident, and these make direct contact with damaged neurons that act in a tissue-protective manner in the M2 phenotype. These results imply that tissue-resident macrophages signal to neurons directly through physical contact.

Memristive Circuit Implementation of a Self-Repairing Network Based on Biological Astrocytes in Robot Application.

A large number of studies have shown that astrocytes can be combined with the presynaptic terminals and postsynaptic spines of neurons to constitute a triple synapse via an endocannabinoid retrograde messenger to achieve a self-repair ability in the human brain. Inspired by the biological self-repair mechanism of astrocytes, this work proposes a self-repairing neuron network circuit that utilizes a memristor to simulate changes in neurotransmitters when a set threshold is reached. The proposed circuit simulates an astrocyte-neuron network and comprises the following: 1) a single-astrocyte-neuron circuit module; 2) an astrocyte-neuron network circuit; 3) a module to detect malfunctions; and 4) a neuron PR (release probability of synaptic transmission) enhancement module. When faults occur in a synapse, the neuron module becomes silent or near silent because of the low PR of the synapses. The circuit can detect faults automatically. The damaged neuron can be repaired by enhancing the PR of other healthy neurons, analogous to the biological repair mechanism of astrocytes. This mechanism helps to repair the damaged circuit. A simulation of the circuit revealed the following: 1) as the number of neurons in the circuit increases, the self-repair ability strengthens and 2) as the number of damaged neurons in the astrocyte-neuron network increases, the self-repair ability weakens, and there is a significant degradation in the performance of the circuit. The self-repairing circuit was used for a robot, and it effectively improved the robots' performance and reliability.

Morphometry of Cortical Neurons in Acute Clozapine and Ethanol Poisoning

The aim of the study is to summarize the histology and morphometry of cortical neurons in acute clozapine and ethanol poisoning.Material and methods. Histological examination of the parietal cortical brain samples of 26 patients died during the Day 1 of acute clozapine and ethanol poisoning (23 males and 3 females aged 22-63 years) was performed. The blood ethanol level was 1.4-4.1%o. The level of clozapine in the blood ranged between 0.24 and 5.8 mg%, in the liver between 0.097 and 6.5 mg%, in kidneys between 0.03 and 3.5 mg%. The cortical samples for morphometric examination were placed in 10% neutral paraformaldehyde, the histological sections were done and stained with hematoxylin and eosin, as well as according to Niessl. The morphological analysis was performed using the video light microscopy. The number of damaged neurons (with separate quantification of reversible, intermediate, and irreversible damage) was assessed. The statistical analysis was done using the non-parametric methods.Results. The signs of brain neuronal damage in acute clozapine and ethanol poisoning, as well as forensic chemical tests, might be used for establishing the direct cause of death.

Down-Regulation of miR-181a-5p Prevents Cerebral Ischemic Injury by Upregulating En2 and Activating Wnt/β-catenin Pathway

PurposeCerebral ischemic injury contributes to severe dysfunction of the brain, which triggers extremely high mortality and disability. The role of microRNA (miR)-181a-5p is documented in cerebral ischemic injury. Therefore, this study intended to further figure out the mechanism of miR-181a-5p in cerebral ischemic injury. MethodsmiR-181a-5p expression in middle cerebral artery occlusion (MCAO) mouse model, oxygen-glucose-deprivation/reoxygenation (OGD/R) N2a cell model, and serum from acute ischemic injury (ACI) patients was evaluated using reverse transcription quantitative polymerase chain reaction (RT-qPCR). Gain- and loss-of-function assays were implemented in MCAO mice and OGD/R-induced N2a cells. In mice, the cerebral infarction area was assessed with 2,3,5-triphenyltetrazolium chloride staining, the number of damaged neurons by Nissl staining, and apoptosis by TdT-mediated dUTP-biotin nick end-labeling staining. Moreover, N2a cell apoptosis and proliferation were determined with flow cytometry or 5-ethynyl-2’-deoxyuridine staining, respectively. The expression of En2 and Wnt/β-catenin pathway-related factors was determined with RT-qPCR and Western blot analysis. The targeting relationship between miR-181a-5p and En2 was evaluated by dual luciferase reporter gene assay. ResultsmiR-181a-5p was highly expressed in serum of ACI patients, MCAO mice, and OGD/R-induced N2a cells. En2, lowly expressed in MCAO mice, was targeted by miR-181a-5p, and miR-181a-5p down-regulation activated the Wnt/β-catenin pathway. Furthermore, miR-181a-5p inhibition or En2 overexpression reduced cerebral infarction area, the number of damaged neurons, and apoptosis in MCAO mice, and also diminished apoptosis and accelerated proliferation of OGD/R-induced N2a cells. ConclusionmiR-181a-5p suppression activated Wnt/β-catenin pathway and sequentially attenuated cerebral ischemic injury by targeting En2.

Functional and Morphological Changes in the Pyramidal Layer of the Hippocampus in Rats with Encephalopathy Induced by Prolonged Exposure to Gravitational Overloading

Studies of morphofunctional changes in the hippocampus using a model of impaired cerebral hemodynamics are needed for understanding the mechanisms of formation of psychoneurological deficits. The aim of the present work was to assess CNS damage and the characteristics of the expression of one of the main regulators of apoptosis – Bcl-2 – in the hippocampus of rats with impaired cerebral hemodynamics induced by repeated gravitational overloading. The study was carried out on Wistar rats which were subjected to gravitational overloading (9 g) in the caudocranial direction for two 5-min periods each day for 28 days. Psychoneurological impairments in the animals were assessed using the McGraw scale and the open field, adhesion, conditioned passive avoidance reaction (CPAR), and escape extrapolation (EET) tests. Brain sections were stained by the Nissl method and the specific numbers of neurons with signs of damage were counted. Immunohistochemical studies of the level of Bcl-2 expression assessed the relative areas of immunoreactive material in the pyramidal layer in all hippocampal fields. Gravitational overloading induced impairments to the animals’ behavior, which was expressed as low movement activity and signs of retrograde amnesia, decreased fi ne motor function, and increases in psychoneurological deficit. Histological studies identified destructive changes to vessels and increases in the specific number of pyramidal neurons with damage in all fields of the hippocampus. Fields CA2 and CA4 showed the greatest increases in the numbers of damaged neurons, along with marked Bcl-2 expression.

Effects of Sodium Ferulate on Cognitive Function in Hippocampus of Chronic Cerebral Hypoperfusion Rats

Objective: To assess sodium ferulate’s effect on cognitive function and p38MAPK signaling in hippocampus of rats with chronic cerebral hypoperfusion (CCH). Methods: 45 male Sprague-Dawley (SD) rats were separated into sham-operation group, CCH model group and treatment group (intraperitoneal injection of 50 mg/kg sodium ferulate). The cognitive function was detected via open-field test, novel object recognition test and Morris water maze test. The activity of superoxide dismutase (SOD) in hippocampal tissues was detected using ELISA kit. Moreover, the neuronal damage in hippocampal tissues was assessed by immunohistochemical method, and apoptosis was assessed via TUNEL staining. Finally, p-p38MAPK signaling protein level in hippocampal tissues was detected via Western blotting. Results: No difference was found in rat autonomic activity among three groups (P &gt; 0.05). The novel object recognition ability of model rats was significantly impaired along with longer escape latency and shorter retention time in the target quadrant (P &lt; 0.01), which were all improved after sodium ferulate treatment (P &lt; 0.01). SOD activity in hippocampal tissues in model rats was significantly reduced and sodium ferulate could significantly increase SOD activity (P &lt; 0.01). There were a large number of damaged neurons and apoptotic cells in hippocampal tissues in model group and sodium ferulate could protect neurons (P &lt; 0.01). The levels of p-p38MAPK, GSP3β and P-tau protein in hippocampal tissues in model group were significantly increased, which were significantly reduced after treatment with sodium ferulate (P &lt; 0.01). Conclusion: Sodium ferulate can protect the CCH-induced cognitive impairment in rats and reduce the CCH-induced damage and apoptosis of hippocampal neurons, possibly through inhibition of p38MAPK signaling pathway.

Opposite Effects of Neuroprotective Cannabinoids, Palmitoylethanolamide, and 2-Arachidonoylglycerol on Function and Morphology of Microglia.

Various studies performed in cultured cells and in in vivo models of neuronal damage showed that cannabinoids exert a neuroprotective effect. The increase in cannabinoids and cannabinoid like substances after stroke has been postulated to limit the content of neuronal injury. As well-accepted, inflammation, and neuronal damage are coupled processes and microglial cells as the main intrinsic immunological effector within the brain play a central role in their regulation. Treatment with the endocannabinoid, 2-arachidonoylglycerol (2-AG) or the endocannabinoid-like substance, palmitoylethanolamide (PEA) affected microglial cells and led to a decrease in the number of damaged neurons after excitotoxical lesion in organotypic hippocampal slice cultures (OHSC). 2-AG activated abnormal cannabidiol (abn-CBD) receptor, PEA was shown to mediate neuroprotection via peroxisome proliferator-activated receptor (PPAR)α. Despite the known neuroprotective and anti-inflammatory properties, the potential synergistic effect, namely possible entourage effect after treatment with the combination of these two protective cannabinoids has not been examined yet. After excitotoxical lesion OHSC were treated with PEA, 2-AG or a combination of both and the number of damaged neurons was evaluated. To investigate the role of microglial cells in PEA and 2-AG mediated protection, primary microglial cell cultures were treated with lipopolysaccharide (LPS) and 2-AG, PEA or a combination of those. Thereafter, we measured NO production, ramification index, proliferation and PPARα distribution in microglial cells. While PEA or 2-AG alone were neuroprotective, their co-application vanished the protective effect. This behavior was independent of microglial cells. Furthermore, PEA and 2-AG had contrary effects on ramification index and on NO production. No significant changes were observed in the proliferation rate of microglial cells after treatment. The expression of PPARα was not changed upon stimulation with PEA or 2-AG, but the distribution was significantly altered. 2-AG and PEA mediated neuroprotection was abolished when co-applied. Both cannabinoids exert contrary effects on morphology and function of microglial cells. Co-application of both cannabinoids with different targets did not lead to a positive additive effect as expected, presumably due to the contrary polarization of microglial cells.

Study of the relationship between how ethanol affects learning and memory and the expression of p21 WAF1/CIP1 in the female mouse hippocampus

The purpose of this study was to investigate the effects of different concentrations of ethanol on learning and memory in female mice and the corresponding interaction with histone deacetylase 1(HDAC1), estrogen receptor α(ERα) and p21 WAF1/CIP1. Data from the Morris water maze test showed that mice in the 50% ethanol group might experience cognitive impairment, while mice in the 2% ethanol group might experience enhanced cognitive capabilities. The number of damaged neurons in the hippocampal CA1 area in the 50% ethanol group was higher than the numbers observed in other groups. The expression of HDAC1 and ERα proteins was lower in the 50% ethanol group than they were in the control group, while p21 WAF1/CIP1 expression was increased. The expression of these proteins in the 2% ethanol group was completely reversed when compared to the 50% ethanol group. p21 WAF1/CIP1 was involved in the cognitive change induced by ethanol. The f2 (−400 bp to −800 bp) and f7 (−2400 bp to −2800 bp) fragments in the p21 WAF1/CIP1 promoter region were functionally active regions that experienced binding relating to HDAC1 and ERα.

Tanshinone IIA improves hypoxic ischemic encephalopathy through TLR‑4‑mediated NF‑κB signal pathway.

Hypoxic ischemic encephalopathy (HIE) is the most common brain injury following hypoxia and/or ischemia caused by various factors during the perinatal period, resulting in detrimental neurological deficits in the nervous system. Tanshinone IIA (Tan-IIA) is a potential agent for the treatment of cardiovascular and cerebrovascular diseases. In this study, the efficacy of Tan-IIA was investigated in a newborn mouse model of HIE. The dynamic mechanism of Tan-IIA was also investigated in the central nervous system of neonate mice. Intravenous injection of Tan-IIA (5 mg/kg) was administered and changes in oxidative stress, inflammation and apoptosis-associated proteins in neurons. Histology and immunohistochemistry was used to determine infarct volume and the number of damaged neurons by Fluoro-Jade C staining. The effects of Tan-IIA on mice with HIE were evaluated by body weight, brain water content, neurobehavioral tests and blood-brain barrier permeability. The results demonstrated that the apoptosis rate was decreased following Tan-IIA administration. Expression levels of pro-apoptotic proteins, caspase-3 and caspase-9 and P53 were downregulated. Expression of Bcl-2 anti-apoptotic proteins was upregulated by Tan-IIA treatment in neuro. Results also found that Tan-IIA treatment decreased production of inflammatory cytokines such as interleukin-1, tumor necrosis factor-α, C-X-C motif chemokine 10, and chemokine (C-C motif) ligand 12. Oxidative stress was also reduced by Tan-IIA in neurons, as determined by the expression levels of superoxide dismutase, glutathione and catalase, and the production of reactive oxygen species. The results demonstrated that Tan-IIA treatment reduced the infarct volume and the number of damaged neurons. Furthermore, body weight, brain water content and blood-brain barrier permeability were markedly improved by Tan-IIA treatment of newborn mice following HIE. Furthermore, the results indicated that Tan-IIA decreased Toll-like receptor-4 (TLR-4) and nuclear factor-κB (NF-κB) expression in neurons. TLR-4 treatment of neuronal cell in vitro addition stimulated NF-κB activity, and further enhanced the production of inflammatory cytokines and oxidative stress levels in neurons. In conclusion, these results suggest that Tan-IIA treatment is beneficial for improvement of HIE through TLR-4-mediated NF-κB signaling.

Effects of activin A and its downstream ERK1/2 in oxygen and glucose deprivation after isoflurane-induced postconditioning.

Isoflurane postconditioning (ISPOC) plays a neuroprotection role in the brain. Previous studies confirmed that isoflurane postconditioning can provide better protection than preconditioning in acute hypoxic-ischemic brain damage, such as acute craniocerebral trauma and ischemic stroke. Numerous studies have reported that activin A can protect rat's brain from cell injury. However, whether activin A and its downstream ERK1/2 were involved in isoflurane postconditioning-induced neuroprotection is unknown. A total of 80 healthy Sprague-Dawley rats weighing 50-70g were randomly divided into 10 groups of 8: normal control, oxygen and glucose deprivation (OGD), 1.5% ISPOC, 3.0% ISPOC, 4.5% ISPOC, blocker of activin A (SB431542), blocker of ERK1/2 (U0126), 3.0% ISPOC+SB431542, 3.0% ISPOC+U0126, and vehicle (dimethyl sulfoxide(DMSO)) group. Blockers (SB431542 and U0126) were used in each concentration of isoflurane before OGD. Hematoxylin-eosin staining, 2,3,5-triphenyl tetrazolium chloride staining, and propidium iodide (PI) staining were conducted to assess the reliability in the brain slices. Immunofluorescence, Western blot, and quantitative real-time PCR(Q-PCR) were performed to validate the protein expression levels of activin A, Smad2/3, P-Smad2/3, ERK1/2, and phosphorylation ERK1/2 (P-ERK1/2). The number of damaged neurons and mean fluorescence intensity(MFI) of PI staining increased, but formazan generation, expression levels of activin A and P-ERK1/2 protein, and mRNA synthesis level of activin A decreased in the OGD group compared with the normal control group (p<0.05). The number of damaged neurons and MFI of PI staining decreased, but formazan production, expression levels of activin A, P-Smad2/3, and P-ERK1/2, and mRNA synthesis level of activin A increased significantly in the 1.5% ISPOC and 3.0% ISPOC groups (p<0.05) compared with the OGD group. The result in the 4.5% ISPOC group, was completely opposite to the 1.5% ISPOC and 3.0% ISPOC groups. The number of damage neuron and MFI of PI staining increased, but formazan production, expression levels of activin A, P-Smad2/3, and P-ERK1/2, and mRNA synthesis level of activin A decreased in the 4.5% ISPOC group. However, the expression levels of activin A, P-Smad2/3, and P-ERK1/2, and mRNA synthesis level of activin A in the 4.5% ISPOC group were higher than the OGD group (p<0.05). The other results were compared between the SB431542 group/the U0126 group and 3.0% ISPOC group. The MFI of PI staining increased, but the expression levels of activin A, P-Smad2/3, and P-ERK1/2 decreased (p<0.05). The expression level of ERK1/2 protein in all groups exhibited no change (p>0.05). Results of this study showed that 3.0% concentration of isoflurane postconditioning provided better neuroprotection than 1.5% and 4.5% concentrations of isoflurane. Activin A/Smad 2/3 and activin A/ERK1/2 signaling pathway may be involved in ISPOC-induced neuroprotection.

Evaluating the protective effects of radon inhalation or ascorbic acid treatment after transient global cerebral ischemic injury in gerbils

ABSTRACTIn this study, we compared the protective effects of radon inhalation and ascorbic acid administration on transient global cerebral ischemic injury in gerbils. Gerbils were treated with radon inhalation (2000 Bq/m3, 24 hours) or ascorbic acid (100, 300, or 500 mg/kg body weight). Then, transient global cerebral ischemia was induced by bilateral occlusion of the common carotid artery. Results showed that the number of damaged neurons was significantly increased in gerbils that underwent ischemia compared with that in control gerbils. However, the number of damaged neurons in gerbils treated with radon or 500 mg/kg of ascorbic acid before ischemia was significantly lower than gerbils who were subjected to ischemia without any pretreatment, and the protective effects of radon inhalation were similar to the effects of administering 500 mg/kg ascorbic acid. The levels of superoxide dismutase (SOD) and total glutathione (t-GSH) in brain tissue were increased to a similar extent by pretreatment with radon inhalation or 500 mg/kg of ascorbic acid. These findings suggested that radon inhalation has a protective antioxidative effect against transient global cerebral ischemic injury similar to 500 mg/kg ascorbic acid treatment.

Lipopolysaccharide preconditioning prevents acceleration of kindling epileptogenesis induced by traumatic brain injury

10–20% of symptomatic epilepsies are post-traumatic. We examined effect of LPS preconditioning on epileptogenesis after controlled cortical impact (CCI). LPS (0.01, 0.1 and 0.5mg/kg) was injected i.p. to rats 5days before induction of CCI to parieto-temporal cortex. Kindling started 24h after CCI by i.p. injection of 30mg/kg of pentylenetetrazole every other day until manifestation of 3 consecutive generalized seizures. CCI injury accelerated the rate of kindled seizures acquisition. LPS (0.1 and 0.5mg/kg) prevented the acceleration of kindling. LPS preconditioning significantly decreased IL-1β and TNF-α over-expression and the number of damaged neurons in the hippocampus of traumatic rats.

Radon inhalation protects against transient global cerebral ischemic injury in gerbils.

Although brain disorders are not the main indication for radon therapy, our previous study suggested that radon inhalation therapy might mitigate brain disorders. In this study, we assessed whether radon inhalation protects against transient global cerebral ischemic injury in gerbils. Gerbils were treated with inhaled radon at a concentration of 2,000 Bq/m(3) for 24 h. After radon inhalation, transient global cerebral ischemia was induced by bilateral occlusion of the common carotid artery. Results showed that transient global cerebral ischemia induced neuronal damage in hippocampal CA1, and the number of damaged neurons was significantly increased compared with control. However, radon treatment inhibited ischemic damage. Superoxide dismutase (SOD) activity in the radon-treated gerbil brain was significantly higher than that in sham-operated gerbils. These findings suggested that radon inhalation activates antioxidative function, especially SOD, thereby inhibiting transient global cerebral ischemic injury in gerbils.

Changes in the expression of astroglial and microglial markers in the hippocampus of rats adapted to chronic stress and the effects of panthenol

We studied the morphological changes and expression of the astroglial and microglial markers in the sensorimotor cortex and hippocampus of rats that were subjected to chronic stress. Chronic neurotization was associated with the appearance of a large number of damaged neurons in layer V of the sensorimotor cortex and the pyramidal layer of the hippocampus. These changes were considerably expressed in the CA3 field. A neurosis-like state in rats was accompanied by an increased expression of microglial markers in the hippocampus and this effect was evident even 1 month after the end of stress. The expression of the astroglial marker GFAP decreased in the CA3 hippocampal field. Treatment of animals with the pantothenic acid derivative panthenol stabilized the glial response to chronic stress; however, its effects were not long-lasting and did not prevent activation of microglia during the period after stress.