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With the decline of ovarian steroids levels at menopause, many women experience an increase in anxiety and stress sensitivity. The locus coeruleus (LC), a central source of noradrenaline (NE), is activated by stress and is inhibited by β-endorphin. Moreover, increased NE has been implicated in pathological anxiety syndromes. Hormone replacement therapy (HRT) in menopause appears to decrease anxiety and vulnerability to stress. Therefore, we questioned the effect of HRT on the inhibitory β–endorphin innervation of the LC. In addition, we found that progesterone protects serotoninergic neurons in monkeys, leading us to question whether ovarian steroids are also neuroprotective in LC neurons in monkeys. Adult Rhesus monkeys (Macaca mulatta) were ovariectomized, and either treated with Silastic capsules that contained estradiol, estratiol + progesterone, progesterone alone or that were empty (ovariectomized;control). After 1 month, the LC was obtained and processed for immunohistochemistry for β-endorphin and terminal deoxynucleotidyl transferase -mediated dUTP-biotin nick end-labeling (TUNEL). The density of β–endorphin axons was determined with image analysis using ImageJ. The TUNEL-positive neurons were counted in the entire LC. progesterone-alone significantly increased the density of the β-endorphin axons in the LC (p

In vivo growth factor (GF) treatment is a promising approach to enhance the regenerative capacity of neural stem cells (NSCs) for brain repair. However, how exogenous GFs affect endogenous NSCs is not well understood. This study investigated the impact of intraventricular administration of fibroblast growth factor 2 and epidermal growth factor on NSCs in the subventricular zone of intact adult mice. GFs were administered for various periods (3, 7, 10, and 14 days), and the proliferation and neuronal production of NSCs were assessed during and after GF treatment. We found that proliferation of NSCs and their progeny is markedly augmented during the first 7 days after the initiation of GF treatment. GF treatment for longer periods, however, did not lead to further increases in the NSC pool, but rather attenuated such proliferation and inhibited neurogenesis. As a result, the production of new olfactory bulb neurons was increased in animals treated with GFs for 7 days but decreased in animals treated for 14 days. These results show time-dependent changes in the response of NSCs to exogenous GFs and demonstrate that precise control of the duration of GF treatment is important for significant enhancement of neuronal production by NSCs in vivo for brain repair.

Isoflurane has either neuroprotective or neurotoxic effects. High-dose oxygen is frequently used throughout the perioperative period. We hypothesized that hyperoxia will affect cell viability of rat pheochromocytoma (PC12) cells that were exposed to isoflurane and reactive oxygen species (ROS) may be involved. PC12 cells were exposed to 1.2% or 2.4% isoflurane for 6 or 24h respectively, and cell viability was evaluated. To investigate the effects of hyperoxia, PC12 cells were treated with 21%, 50%, or 95% oxygen and 2.4% isoflurane for 6h, and cell viability, TUNEL staining, ROS production, and expression of B-cell lymphoma 2 (BCL-2), BCL2-associated X protein (BAX), caspase-3 and beta-site APP cleaving enzyme (BACE) were measured. ROS involvement was evaluated using the ROS scavenger 2-mercaptopropiopylglycine (MPG). The viability of cells exposed to 2.4% isoflurane was lower than that of cells exposed to 1.2% isoflurane. Prolonged exposure (6h vs. 24h) to 2.4% isoflurane resulted in a profound reduction in cell viability. Treatment with 95% (but not 50%) oxygen enhanced the decrease in cell viability induced by 2.4% isoflurane alone. Levels of ROS, Bax, caspase-3 and BACE were increased, whereas expression of Bcl-2 was decreased, in cells treated with 95% oxygen plus 2.4% isoflurane compared with the control and 2.4% isoflurane plus air groups. MPG attenuated the effects of oxygen and isoflurane. In conclusion, isoflurane affects cell viability in a dose- and time-dependent manner. This effect is augmented by hyperoxia and may involve ROS, the mitochondrial apoptotic signaling pathway, and β-amyloid protein.

Objective Delayed neuropsychological sequelae (DNS) are the most common and serious effects of severe carbon monoxide (CO) poisoning, occurring in approximately half of all CO poisoning cases. Growing evidence suggests that oxidative stress and secondary reactions in delayed brain injury are crucial to CO toxicity, similar to ischaemia–reperfusion injury. Exogenous methane plays a protective role in ischaemia–reperfusion injury by affecting key events through anti-oxidant, anti-inflammatory, and anti-apoptosis actions. Our study aimed to explore the potential of exogenous methane to relieve the severity of DNS. Methods Thirty-six male Sprague–Dawley (SD) rats were divided into three groups of normal-, CO- and CO plus methane-treated rats. The rats in the latter two groups were exposed to 1000 ppm CO for 40 min and then to 3000 ppm CO for another 20 min. Following CO exposure, saline or methane saline (10 ml/kg) was intraperitoneally administered to rats in the CO group or the CO plus methane group, respectively. On the ninth day after CO exposure, Morris water maze testing, histological analysis, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) and immunohistochemical labelling were performed on 6 rats in each group. The remaining 6 rats in each group were used to detect oxidative damage markers, inflammatory cytokines and apoptosis proteins. Results Methane significantly improved CO-impaired pathological characteristics as well as learning and memory performance. In addition, methane significantly increased the superoxide dismutase (SOD) activity, lowered the CO-increased level of malondialdehyde (MDA) 3-nitrotyrosine (3-NT) and 8-hydroxy-2-deoxyguanosine (8-OHdG), inhibited levels of tumour necrosis factor-α (TNF-α), interleukin 1-β (IL1-β) and caspase-3 in the rat cerebral cortex and hippocampus but had no effect on IL-6 levels. Conclusion The hippocampus was the main target of CO-induced alterations in the rat brain compared to the cerebral cortex. Methane treatment protected the rat brain from the harmful effects induced by CO exposure and improved the outcome of DNS through anti-oxidant, anti-inflammatory and anti-apoptosis activities.

Fear memory is essential for survival, and its dysregulation leads to disorders. High altitude hypobaric hypoxia (HH) is known to induce cognitive decline. However, its effect on fear memory is still an enigma. We aimed to investigate the temporal effect of HH on fear conditioning and the underlying mechanism. Adult male Sprague-Dawley rats were trained for fear conditioning and exposed to simulated HH equivalent to 25,000 ft for different durations (1, 3, 7, 14 and 21 days). Subsequently, rats were tested for cued and contextual fear conditioning. Neuronal morphology, apoptosis and DNA fragmentation were studied in the medial prefrontal cortex (mPFC), hippocampus and basolateral amygdala (BLA). We observed significant deficit in cued and contextual fear acquisition (at 1, 3 and 7 days) and consolidation (cued at 1 and 3 days and contextual fear at 1, 3 and 7 days) under HH. HH exposure with retraining showed the earlier restoration of contextual fear memory. Further, we found a gradual increase in the number of pyknotic and apoptotic neurons together with the increase in DNA fragmentation in mPFC, hippocampus, and BLA up to 7 days of HH exposure. The present study concludes that HH exposure equivalent to 25,000 ft induced cued and contextual fear memory deficit (acquisition and consolidation) which is found to be correlated with the neurodegenerative changes in the limbic brain regions.

Mitochondria involve in the determination of ischemic neuronal cell fate through regulation of apoptotic and necrotic cell death. Phosphatase and tensin homolog (PTEN) protein negatively regulates Akt/PKB signaling which is the major cell survival pathway. The current study aimed to examine the impact of SF1670, a potent PTEN inhibitor, on mitochondria-mediated cell survival pathways in an in vitro stroke-like model. PC12 cells were exposed to one hour oxygen and glucose deprivation (OGD) followed by different time points of reperfusion (0, 30, 60, 120 and 180 min) and SF1670 treatments. Our findings showed that OGD/R exposure increased reactive oxygen species (ROS) levels, reduced phosphorylated Akt (p-Akt), ratios of Bcl-2/BAX, intracellular ATP, mitochondrial vital activity and mitochondrial membrane potential (Δψm). OGD/R exposure also increased cleaved caspase 3/pro-caspase 3 and cleaved caspase 9/pro-caspase 9 ratios associated with low cell viability, high lactate dehydrogenase (LDH) release, and greater apoptotic cell death in the TUNEL assay. Conversely, inhibition of PTEN by SF1670 were associated with increased expression of p-Akt and anti-apoptotic proteins (Bcl-2), attenuated pro-apoptotic proteins (BAX) and oxidative stress index (ROS), improved mitochondrial function (restored MMP and ATP), and decreased apoptotic cell death. These results strongly suggest that neuroprotective effect of SF1670 against OGD/R-induced cell death at least is partially mediated through mitoprotective properties of SF1670.

We have previously shown that astaxanthin (ATX) reduces the blood-brain barrier (BBB) disruption and neurovascular dysfunction following subarachnoid hemorrhage (SAH) insults. However, the underlying mechanisms remain unclear. It is known that the matrix metalloproteinases (MMPs), especially matrix metalloproteinase-9 (MMP-9) plays a crucial role in the pathogenesis of secondary brain injury after SAH. And ATX has the ability to regulate MMP-9 in other models. Herein, we investigated whether ATX could ameliorate MMP-9 activation and expression in a rat model of SAH. A total of 144 rats were randomly divided into the following groups: control group (n=36), SAH group (n=36), SAH+vehicle group (n=36), and SAH+ATX group (n=36). The SAH model was induced by injection of 0.3 ml autologous blood into the prechiasmatic cistern. ATX (20 μl of 0.1 mmol) or vehicle was administered intracerebroventricularly 30 min after SAH induction. Mortality, neurological function, brain edema and blood-brain barrier (BBB) permeability were measured at 24 and 72 h after SAH. Biochemical and zymographic methods were used to analyze MMP-9 expression and activity in brain samples. Immunohistochemistry and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining were also evaluated at 24h. Our data indicated that ATX could significantly reduce the expression and activity of MMP-9, leading to the amelioration of brain edema, BBB impairment, neurological deficits and TUNEL-positive cells at 24h but not 72 h after SAH. The ATX-mediated down-regulation of MMP-9 was correlated with the decreased levels of IL-1β, TNF-α, oxidative stress, activated microglia and infiltrating neutrophils. These results suggest that the neurovascular protection of ATX in SAH is partly associated with the inhibition of MMP-9 expression and activity.

JM-1232(−) (JM) is a novel isoindoline derivative with sedative and hypnotic activities that are mediated by binding to the benzodiazepine site of the Gamma-aminobutyric acid type A (GABAA) receptor. Although the neuroprotective effects of other GABAA receptor agonists are well known, there is no published report regarding JM. Thus, we examined the effects of JM on neurons exposed to oxygen-glucose deprivation (OGD) using rat hippocampal slice cultures. Hippocampal slices were assigned to either control or JM-administered groups. To assess the neuroprotective effects of JM from necrotic changes, we measured the fluorescence of propidium iodide and compared the cell mortality 24 h following OGD between the control and JM-administered groups. We also verified that the effects of JM were mediated by GABAA receptors by adding flumazenil, a benzodiazepine receptor antagonist, in the same experimental settings. JM, at concentrations of 250 and 500 µM, significantly reduced cell mortality in pyramidal neurons after OGD; however, flumazenil did not inhibit this effect. To analyze more immediate effects of JM, we next measured the fluorescence of Oregon Green 488 BAPTA-1 during the OGD and re-oxygenation periods, and evaluated changes in intracellular Ca2+ in single CA1 pyramidal neurons. JM reduced the elevation of intracellular Ca2+ concentration during OGD, and this effect was antagonized by flumazenil. These findings indicate that JM suppressed the elevation of intracellular Ca2+ concentration during OGD through GABAA receptors, but its neuroprotective effects from necrotic changes also involve other unknown mechanisms.

An urgent need exists to develop intra-arterial treatment for acute ischemic stroke in animal study. This study aimed to explore the beneficial effects of intra-arterial administration of human urinary kallidinogenase (HUK) on brain injury after permanent middle cerebral artery occlusion (pMCAO) in a rat model, and the potential underlying molecular mechanisms. Brain injury induced by pMCAO was evaluated through measuring neurological deficit scores, neuropathological changes, and inflammatory factors. Neurological deficits were observed 24 h after pMCAO and were alleviated by intra-arterial HUK treatment obviously. Inhibition of PI3K by LY294002 blocked the beneficial effect of HUK on neurological functions. In contrast to the pMCAO group, the intra-arterial HUK treatment group showed relatively more regularly arranged neurons and fewer pyknosis. Neurodegeneration, necrosis, infarct area and markers for brain injury were all ameliorated by intra-arterial HUK treatment. Moreover, a lower expression of inflammatory factors including interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, and a higher expression of IL-10 were observed in the intra-arterial HUK treatment group than that in the pMCAO group. Additionally, when comparing with pMCAO group, a lower level of caspase-3, bax, and apoptotic rate, and a higher level of bcl-2, p-PI3K, p-AKT and p-FoxO1were observed in the pMCAO + HUK group. These results suggest that intra-arterial administration of HUK is a promising therapeutic strategy against pMCAO induced brain injury, and PI3K/AKT/FoxO1 signaling pathway may be involved in this process.

JNK, a member of the mitogen activated protein kinases (MAPKs) superfamily, plays a key role in cell death in many neurological disorders, but systemic inhibition of JNK has detrimental side effects. JNK can be regulated by two direct upstream kinases: MAPK kinase 4 (MKK4) and MAPK kinase 7 (MKK7). Here, we investigated the effect of GADD45β-I, a recently designed cell-permeable inhibitor peptide for MKK7, on endoplasmic reticulum (ER) stress-induced cytotoxicity in neuronal HT22 cells. We found that treatment with the ER stress inducer tunicamycin (TM) increased the phosphorylation of JNK and MKK7 in HT22 cells, which was nullified by GADD45β-I. GADD45β-I significantly attenuated TM-induced toxicity via inhibiting apoptotic cell death, as evidenced by decreased number of TUNEL-positive cells and reduced caspase-3 activity. GADD45β-I treatment also decreased expression of ER stress associated pro-apoptotic proteins and prevented morphological changes of the ER after TM exposure. In addition, inhibition of mitochondrial oxidative stress and preservation of intracellular ATP levels were observed in GADD45β-I-treated cells. The experiments using siRNA transfection and Topflash reporter assay revealed a possible involvement of Wnt/β-catenin pathway in GADD45β-I-induced protection in HT22 cells. In summary, our results demonstrated that GADD45β-I exerted protective effects against TM-induced cytotoxicity via regulating JNK-Wnt pathway. Targeting MKK7 could represent a new therapeutic strategy for the treatment of neurological diseases where ER stress associated neuronal injury are involved.

Background Isoflurane and sevoflurane are widely used anesthetics in surgery and administration of these anesthetics could lead to postoperative cognitive dysfunction (POCD). However, the mechanisms remain unclear. Methods Aged Wistar rats were exposed to isoflurane and sevoflurane for 2 or 4 h. Recognition memory and spatial working memory were measured using Novel object recognition (NOR) and Y-maze test, respectively. Apoptotic cells were detected by TUNEL staining. miRNA expression was measured by Real-time PCR while protein expression was measured by Western blot. Dual-Luciferase reporter assay was used to establish the direct relationship between miRNAs and Gabra5 and gephyrin gene expression. Results Exposure to isoflurane and sevoflurane for 2 or 4 h significantly decreased the NOR index in the NOR test and spontaneous alternations in arm entries in the Y-maze test in aged rats. TUNEL staining showed that isoflurane and sevoflurane administration significantly induced apoptosis in the mPFC and hippocampus. The protein level of α5 GABAA receptor (α5GABAAR), gephyrin, and dystrophin were significantly increased, whereas the expression of miR-30a, miR-31, miR-190a, and miR-190b was significantly decreased in the hippocampus and mPFC in aged rats exposed to isoflurane and sevoflurane compared to control rats. The protein levels of α5GABAAR, gephyrin, and dystrophin protein in the hippocampus and the mPFC significantly correlated with NOR index and spontaneous alternations. Dual-Luciferase reporter assay showed that miR-30a and miR-190a/b mimics significantly inhibited Gabra5 and gephyrin gene expression, respectively. Conclusion There might be a miRNAs-GABAergic transmission pathway which may be involved in the pathophysiological alteration in anesthetics-induced POCD.

6-Hydroxydopamine (6-OHDA) is a neurotoxin that is commonly employed to induce lesions of the dopaminergic pathways to generating experimental models of Parkinson’s disease (PD) in rodents. Antioxidant and anti-inflammatory therapy approaches have been the focus of attention in the treatment of neurodegenerative. PD and Alzheimer’s diseases, and oxidative stress have been implicated in these diseases. In this study, we investigated the neuroprotective effects of minocycline and the signalling pathway that is possibly involved in a PC12 cell model of PD. The results indicated that 6-OHDA cytotoxicity was accompanied by an increment in lactate dehydrogenase (LDH) release, an increase in caspase-3 protein activity, an increase in ROS generation, MDA content and decrease in the SOD, CAT activities and cell viability. Moreover, treatment with 6-OHDA alone for 24 h resulted in ICAD degradation, increased nuclear translocation of NF-κB, and increased p53 expression. However, pretreatment with minocycline (5, 10, 20 µM) for 24 h significantly reduced LDH release, reduced caspase-3 protein production, reduced ROS production, MDA content and attenuated the decrease in SOD, CAT activities and cell viability. Additionally, minocycline (20 µM) markedly decreased the levels of cleaved ICAD protein, down-regulated p53 activity and inhibited the nuclear translocation of NF-κB. The neuroprotective effects of minocycline were attributable to its potent antioxidant activities, which prevented the nuclear translocation of NF-κB and the subsequent promotion of cell death. Therefore, the present study supports the notion that minocycline may be a promising neuroprotective agent for the treatment of Parkinson’s disease.

The aim of this study was to investigate the neuroprotective effects of yokukansan, a traditional Kampo medicine, on the behavioral dysfunction induced by cerebral ischemia/reperfusion injury in gerbils. Gerbils were treated with yokukasan by oral gavage for 30 days, once per day, until the day before induction of ischemia, which was induced by occluding the bilateral common carotid artery for 5 min. The effects of yokukansan (50, 100 and 300 mg/kg) were examined by measuring neuronal damage and behavioral deficits (locomotor activity, 8-arm radial maze task). The anti-inflammatory and anti-oxidant properties of yokukansan were also examined. Administration of yokukansan at 300 mg/kg significantly reduced hippocampal neuronal death after brain ischemia, inhibited the ischemia-induced inflammatory response and DNA oxidative damage. Yokukansan also reduced ischemia-induced locomotor hyperactivity and improved memory impairment. These findings suggest that yokukansan can inhibit the inflammatory response, oxidative damage and subsequent neuronal death induced by cerebral ischemia/reperfusion injury, and also can contribute to improvement in neurological deficits following such injury.

Emerging experimental and clinical data suggest that severe illness, such as traumatic brain injury (TBI), can induce critical illness-related corticosteroid insufficiency (CIRCI). However, underlying mechanisms of this TBI-associated CIRCI remain poorly understood. We hypothesized that dexamethasone (DXM), a synthetic glucocorticoid, which was widely used to treat TBI, induces hypothalamic neuronal apoptosis to aggravate CIRCI. To test this hypothesis, we have evaluated the dose effect of DXM (1 or 10mg/kg) on the development of acute CIRCI in rats with fluid percussion injury-induced TBI and on cultured rat hypothalamic neurons in vitro (DXM, 10(-5)-10(-8)mol/L). Corticosterone Increase Index was recorded as the marker for CIRCI. In addition, MTT and TUNEL assays were used to measure the viability and apoptosis of hypothalamic neurons in primary culture. Moreover, high-resolution hopping probe ion conductance microscopy (HPICM) was used to monitor the DXM-induced morphological changes in neurons. The incidence of acute CIRCI was significantly higher in the high-dose DXM group on post-injury day 7. Cellular viability was significantly decreased from 12h to 24h after the treatment with a high-dose of DXM. A significantly increase in TUNEL positive cells were detected in cultured cells treated with a high-dose of DXM after 18h. Neurites of hypothalamic neuron were dramatically thinner and the numbers of dendritic beadings increased in neurons treated with the high dose of DXM for 12h. In conclusion, high-dose DXM induced hypothalamic neurons to undergo apoptosis in vivo and in vitro, which may aggravate TBI-associated CIRCI.

Different signaling pathways are involved in tissue protection against ischemia reperfusion (IR) injury, among them mammalian target of rapamycin (mTOR) and related pathways have been examined in many recent studies. Present study evaluated the role of mTOR in remote ischemic preconditioning (RIPC) of hippocampus. Renal ischemia was induced (3 cycles of 5min occlusion and 5min reperfusion of unilateral renal artery) 24h before global brain ischemia (20min bilateral common carotid artery occlusion). Saline or rapamycin (mTOR inhibitor; 5mg/kg, i.p.) was injected 30min before RIPC. mTOR and phosphorylated mTOR (p-mTOR) expression, superoxide dismutase (SOD) activity and retention trial of passive avoidance test were determined 24h after global ischemia. Apoptosis and neuronal cell density were assessed 72h after hippocampal ischemia. RIPC decreased apoptosis (p0.05 vs. IR), improved memory (p0.05 vs. IR), and augmented p-mTOR expression and SOD activity after hippocampal ischemia (p0.05 vs. IR). Rapamycin abolished all protective effects of RIPC (p0.05 vs. RIPC+IR) suggesting a role for mTOR in RIPC induced hippocampal protection.

Stress predisposes the brain to various neuropathological disorders. Fibrates like gemfibrozil, commonly used for hyperlipidemia, have not yet been examined for their protective/deteriorative potential against restraint stress-induced disturbances. Pretreatment of rats with a range of gemfibrozil concentrations showed significant protection against stress consequences at 90 mg/kg of gemfibrozil, as it resulted in the highest level of antioxidant defense system potentiation among other doses. It also reduced plasma corticosterone compared with the stressed animals. Administration of gemfibrozil (90 mg/kg) before stress induction was able to significantly induce the protein levels of some protective factors including hemeoxygenase-1 (HO-1) and NAD(P)H dehydrogenase quinone-1 (NQO-1) in the antioxidant nuclear factor erythroid-derived 2-like 2 (Nrf-2) pathway, as well as mitochondrial pro-survival proteins, including peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and nuclear respiratory factor 1 (NRF-1). In parallel, the level of cleaved caspase-3 and apoptosis-inducing factor (AIF), two proteins involved in apoptotic cell death, and the number of damaged neurons detected in hematoxylin-eosin (H&E) stained hippocampus sections were suppressed in the presence of gemfibrozil. Herein, although gemfibrozil demonstrated protection against the restraint stress, considering its dose and context-dependent effects reported in the previous studies, as well as its common application in clinic, further investigations are essential to unravel its exact beneficial/deleterious effects in various neuronal contexts.

Paired box 3 (PAX3) is overexpressed in glioma tissues compared to normal brain tissues, however, the pathogenic role of PAX3 in human glioma cells remains to be elucidated. In this study, we selected the human glioma cell lines U251, U87, SHG-44, and the normal human astrocytes, 1800, which have differential PAX3 expression depending upon the person. SiRNA targeting PAX3 and PAX3 overexpression vectors were transfected into U87 and SHG-44 glioma cell lines, and cell proliferation, invasion, apoptosis, and differentiation were examined by CCK-8 assays, transwell chamber assays, tunnel staining, Annexin V/PI analysis, and Western blotting, respectively. In addition, we used subcutaneous tumor models to study the effect of PAX3 on the growth of glioma cells in vivo. We found that PAX3 was upregulated in the three glioma cell lines. PAX3 knockdown inhibited cell proliferation and invasion, and induced apoptosis in the U87MG glioblastoma cell line, whereas PAX3 upregulation promoted proliferation, inhibited apoptosis, and increased invasion in the SHG-44 glioma cell line. Moreover, we found that targeting PAX3 expression in glioma cell lines together with chemotherapeutic treatment could increase glioma cell susceptibility to the drug. In subcutaneous tumor models in nude mice using glioma cell lines U-87MG and SHG-44, inhibition of PAX3 expression in glioblastoma U-87MG cells suppressed tumorigenicity, and upregulation of PAX3 expression in glioma SHG-44 cells promoted tumor formation in vivo. These results indicate that PAX3 in glioma is essential for gliomagenesis; thus, targeting PAX3 or its downstream targets may lead to novel therapies for this disease.

To study the effects of 2,2',4,4',5,5'-hexa-brominated diphenyl ether (BDE-153) exposure during lactation on the learning and memory abilities, spontaneous behavior and brain cells of adult rats and to elicit basic information on PBDE's developmental neurotoxicity.Newborn male rat pups were randomly categorized into the following groups (15 pups per group), according to their weights and litters: a control group, and 1mg/kg, 5mg/kg and 10mg/kg BDE-153 groups. At postnatal day 10 (PND10), the pups in the BDE-153 groups were intraperitoneally injected once with BDE-153 plant oil solutions at 0.1ml/10g body weight, and the controls were injected with plant oil. Throughout the entire experiment, physiological measures were recorded, such as food and water consumption, body weight and clinical symptoms. At 1 month and 2 months after treatment, the learning and memory abilities of the rats were tested by the Morris water maze test, the step-down test, and the step-through test; spontaneous behavior was tested by the open-field test. After all tests were accomplished, rats were weighed and sacrificed, and the brain tissue was immediately isolated and divided into two parts. Sections were fabricated from one part, and changes in the morphology and ultrastructure in CA3 region of hippocampus were observed under an optical microscope and transmission electron microscope, along with the detection of apoptotic cells with the terminal-deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) method. The tissue of the second part was digested into single-cell suspension liquid, and the cell apoptosis was assayed with flow cytometry and the lactate dehydrogenase (LDH) leakage was detected with spectrophotometry.There was no obvious change in food and water consumption, body weight and the ratio of brain to body weight, or any overt clinical symptoms in the BDE-153-treated rats. Compared to the control group, rats' latency time in the test session (LT2) in the step-down test was significantly increased in the 10mg/kg BDE-153 group at 2 months after treatment (P0.05), and the BDE-153-treated rats' swimming times and distances in the target quadrant were significantly decreased at 1 month and 2 months after treatment (P0.05 or P0.01). These parameters were also significantly increased in the opposite quadrant at 1 month after treatment (P0.05 or P0.01). The spontaneous behavior was significantly reduced in the treated groups compared to the controls (P0.05 or P0.01). The severity of neurobehavioral dysfunction was dependent on the exposure dose of BDE-153, and worsened with age. Under an optical microscope, the treated rats' neurons in the CA3 region of the hippocampus were observed to be reduced and disarranged, and the cell junctions were loosened and the intercellular spaces were enlarged. Under a transmission electron microscope, the cell nucleus was observed to shrink; the chromatin was condensed and gathered near the nuclear membrane, the Nissl bodies and other organelles in the perikaryon were reduced, and the vacuole was observed to degenerate and even disappear. Moreover, compared to the controls, the cell apoptosis rates were significantly increased in the 5 and 10mg/kg BDE-153 groups (P0.05), and the LDH activity was significantly increased in the 10mg/kg BDE-153 groups (P0.01).Lactation exposure to BDE-153 damaged adult rats' learning and memory abilities, disrupted their spontaneous behavior (hypoactivity) and induced hippocampus neuron apoptosis.

After spinal cord injury (SCI), a series of complex pathophysiological processes follows the initial injury. Because inflammation plays a key role in this secondary pathology damage, anti-inflammatory drug treatment may reduce secondary damage and protect neurons after SCI. Though nordihydroguaiaretic acid (NDGA) can inhibit inflammatory responses, its potential roles in neuroprotection and anti- inflammation in an SCI model have not been studied. In this study, we investigated the anti-inflammatory effects of NDGA in SCI. First, histopathological alterations were evaluated with hematoxylin/eosin (HE) and Nissl staining, showing an increased number of neurons after NDGA administration. Additionally, the extent of secondary damage was assessed by TUNEL assay and measurement of astrocyte proliferation. The data showed that the numbers of apoptotic cells and the proliferative extent of astrocytes were significantly decreased by the use of NDGA. The anti-inflammatory effect of NDGA was evaluated by measuring myeloperoxidase (MPO) levels as an indicator of neutrophil activity, macrophage/microglia numbers, and expression of inflammatory cytokines including IL-1β and TNF-α. NDGA treatment significantly decreased the MPO level and the number of macrophages/microglia. In addition, NDGA also suppressed the expression of IL-1β and TNF-α after SCI. These data suggest that anti-inflammatory action by NDGA can reduce secondary damage after SCI.

Analgesics and sedatives are frequently used in the treatment of acute brain injury and subsequent brain swelling. Most agents act on specific receptors to modulate neuronal activity, which is normally involved in feedback loops that direct system building and maintenance. We investigated the neurodegenerative effects of midazolam and isoflurane in a rat model of controlled cortical impact injury (CCII). Two hours prior to CCII, four experimental groups were treated with different agents including a minimum alveolar concentration (MAC 1.0) of isoflurane. For additional sedation, isoflurane MAC 1.67, midazolam alone, or midazolam in combination with flumazenil was used. Blood pressure and blood gas analysis were monitored to investigate systemic side effects. Two days after treatment, relative apoptotic cell counts were determined by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method. With isoflurane and midazolam, electroencephalographic (EEG) recordings revealed a decrease in amplitude size and altered frequency distribution. Treatment using deep sedation with isoflurane MAC 1.67 or midazolam increased relative apoptotic cell count by 14.8% (95% CI 3.6 to 26.1, p

2Cl-C.OXT-A (COA-Cl) is a novel nucleic acid analog that enhances angiogenesis through extracellular signal-regulated kinase 1 or 2 (ERK1/2) activation. ERK1/2 is a well-known kinase that regulates cell survival, proliferation and differentiation in the central nervous system. We performed in vitro and in vivo experiments to investigate whether COA-Cl can attenuate neuronal damage and enhance recovery after brain ischemia. In primary cortical neuron cultures, COA-Cl prevented neuronal injury after 2h of oxygen-glucose deprivation. COA-Cl increased phospho-ERK levels in a dose-dependent manner and COA-Cl-induced neuroprotection and ERK1/2 activation was inhibited by suramin or PD98059. The effect of COA-Cl was evaluated in vivo with 60min of middle cerebral artery occlusion combined with bilateral common carotid artery occlusion. COA-Cl or saline was injected intracerebroventricularly 5min after reperfusion. COA-Cl significantly reduced infarct volume and improved neurological deficits upon injection of 15 or 30μg/kg COA-Cl. Moreover, COA-Cl reduced the number of TUNEL positive cells in ischemic boundary, while rCBF was not significantly changed by COA-Cl administration. We also evaluated the effect of delayed COA-Cl administration on recovery from brain ischemia by continuous administration of COA-Cl from 1 to 8 days after reperfusion. Delayed continuous COA-Cl administration also reduced infarct volume. Furthermore, COA-Cl enhanced peri-infarct angiogenesis and synaptogenesis, resulting in improved motor function recovery. Our findings demonstrate that COA-Cl exerts both neuroprotective and neurorestorative effects over a broad therapeutic time window, suggesting COA-Cl might be a novel and potent therapeutic agent for ischemic stroke.

Cerebellar Purkinje cells (PCs) die in humans leading to a variety of diseases including ataxia and essential tremor. The etiology underlying PC death is poorly understood. Shaker mutant rat is a unique animal model of progressive PC degeneration that is compartmentalized and of adult-onset. In shaker mutant rats, hereditary degeneration of at risk PCs occurs between 7 and 14 postnatal weeks of age as a natural phenotypic expression of the shaker mutation and at earlier or later ages depending upon experimental conditions in restricted anterior (ADC) and posterior (PDC) vermal degeneration compartments. Secure PCs in a flocculonodular survival compartment (FNSC) always survive. In this study, we investigated DNA fragmentation and active caspase-3 expression characteristic of apoptosis using immunofluorescence and fluorescence microscopy. We also sought to confirm the occurrence of apoptosis in at risk PCs using transmission electron microscope. Purkinje neurons were the only cerebellar cells labeled for TUNEL and immunoreactive to active caspase-3 in the shaker mutant. Active caspase-3 expression observed was spatially and temporally congruous with the pattern of calbindin immunolabeling of degenerating PCs that is characterized by dendritic atrophy, shrinkage of PC cell bodies and the appearance of PC axonal torpedoes. DNA fragmentation, detected by TUNEL, as well as ultrastructural morphological changes characteristic for apoptosis, provided additional evidence for the occurrence of apoptosis in at risk PCs.

We aimed to examine the protective effects of resveratrol against homocysteine induced oxidative stress, apoptosis and cognitive impairment. Rats were randomly divided into three groups. Control group received standard rat food; homocysteine group (Hcy group) received daily methionine at a dose of 1g/kg-body weight dissolved in drinking water for thirty days; third group (Hcy+Res group) received same amount of methionine plus 20mg/kg/day resveratrol intraperitoneally for thirty days. Cognitive performances of the animals were tested by Morris water maze test. Then all animals were sacrificed to study lipid peroxidation (LPO), DNA fragmentation and p53 mRNA expression in the rat brain. The aortas of the sacrificed rats were processed for histopathological examination. Apoptosis in the aortas was assessed by TUNEL staining. Resveratrol significantly decreased serum levels of homocysteine, reversed Hcy induced LPO increase, decreased DNA fragmentation and p53 mRNA expression in the rat brains, and improved homocysteine induced impairment of long term spatial memory. Resveratrol could inhibit homocysteine induced apoptosis and histopathological deterioration in the rat aortic sections. In conclusion, resveratrol is effective in preventing homocysteine induced vascular and neural defects. In hyperhomocysteinemic rat model, our findings consequently warrant in future studies to reveal the true improvement mechanism of resveratrol.

Recanalization and secondary prevention are the main therapeutic strategies for acute ischemic stroke. Neuroprotective therapies have also been investigated despite unsuccessful clinical results. Coenzyme Q10 (CoQ10), which is an essential cofactor for electron transport in mitochondria, is known to have an antioxidant effect. We investigated the protective effects of CoQ10 against hypoxia in neural stem cells (NSCs). We measured cell viability and levels of intracellular signaling proteins after treatment with several concentrations of CoQ10 under hypoxia-reperfusion. CoQ10 protected NSCs against hypoxia-reperfusion in a concentration-dependent manner by reducing growth inhibition and inhibiting free radical formation. It increased the expression of a number of survival-related proteins such as phosphorylated Akt (pAkt), phosphorylated glycogen synthase kinase 3-β (pGSK3-β), and B-cell lymphoma 2 (Bcl-2) in NSCs injured by hypoxia-reperfusion and reduced the expression of death-related proteins such as cleaved caspase-3. We conclude that CoQ10 has effects against hypoxia-reperfusion induced damage to NSCs by enhancing survival signals and decreasing death signals.

VEGF is the major angiogenic and vascular permeability factor in health and disease. Vascular development depends on function, and in sensory areas is experience-dependent. Our aim was to investigate, qualitatively and quantitatively, the effects of intracortical infusion and neutralisation of VEGF during the first days of the critical visual period, when peak levels of endogenous VEGF secretion are reached. VEGF was intracortically delivered into middle cortical layers of P18 Long-Evans rats. Another cohort received anti-VEGF. Vehicle (PBS)-infused and non-operated animals were used as controls. Various immunopathological analyses were performed: Endothelial Barrier Antigen (EBA) for the BBB integrity and GFAP for astroglial response. Vascular density was measured by Butyryl Cholinesterase Histochemistry, neuronal density by NeuN immunohistochemistry and apoptosis by TUNEL staining. VEGF levels were measured by Western Blot. Decreased vascular permeability was evoked in VEGF-infused rats whilst EBA expression remained constant, suggesting a preserved BBB function. When VEGF was blocked, tissue showed a higher degree of extravasation and a decreased number of EBA-positive vessels surrounding the injury. Lesion induced by cannula implantation annulled the normal increase in vascular density and the decrease in neuronal density during this time. VEGF rescued in part the vascular increase, and also prevented physiological and pathological neuronal death. VEGF blockade induced a higher amount of neural loss and lower astrocytic reaction. Our results support the role of VEGF as extending beyond vascularization, preventing physiological and pathological neuronal death, not only in the injured hemisphere but also in the intact one suggesting a process of transhemispheric diaschisis.

With fusion or fission, mitochondria alter their morphology in response to various physiological and pathological stimuli resulting in either elongated, tubular, interconnected or fragmented form. Immunohistochemistry and Western blot analyses were performed at 2, 7, 14 and 28 d after 90 min of transient middle cerebral artery occlusion (tMCAO) in mice. The present study showed that mitochondrial fission protein fission 1 (Fis1) and phosphorylated dynamin-related protein 1 (P-Drp1) both progressively increased with the peak at 14 d after tMCAO. Double immunofluorescent analysis showed the number of double positive cells with Fis1/Drp1 reduced between 2 and 28 d after 90 min of tMCAO, and also showed some double positive cells with Fis1/terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL) in the peri-infract regions at 2d after the reperfusion. The present study suggests a progressive activation of mitochondrial fission proteins Fis1 and P-Drp1 in relation to apoptotic process in neural cells of the peri-infract regions after tMCAO.

Remote ischemic postconditioning (RIPoC) attenuates ischemia/reperfusion (I/R) injury in the heart, lung and hind limb. RIPoC performed in the hind limb reduces brain injury following focal cerebral ischemia in rats. Whether RIPoC has a neuroprotective effect with respect to global cerebral I/R injury is, however, unknown, and the mechanism of neuroprotection needs further elucidation. Here we investigated whether RIPoC could reduce global cerebral I/R injury in rats and whether this neuroprotective effect was induced by up-regulating endothelial nitric oxide synthase (eNOS) through the phosphatidylinositol-3 kinase/Akt (PI3K/Akt) pathway. Global cerebral ischemia was performed via 8min of four-vessel occlusion. Neuronal density, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells and expression of Bcl-2 and Bax in the hippocampal CA1 region were assessed after reperfusion. Morris water maze task was used to quantify spatial learning and memory deficits after reperfusion. The expression of eNOS, phosphorylated eNOS (Ser1177), Akt and phosphorylated Akt (Ser473) in the CA1 region was measured after reperfusion. RIPoC significantly attenuated delayed neuronal death and reduced the spatial learning and memory deficits associated with global cerebral ischemia. Pre-administration of N(ω)-nitro-l-arginine methyl ester (a nonselective NOS inhibitor) significantly abolished the neuroprotective effect of RIPoC. Moreover, pre-administration of LY294002 (a highly selective inhibitor of PI3K) not only significantly reversed the neuroprotective effect of RIPoC, but also obviously inhibited the up-regulation of eNOS induced by RIPoC. Our findings suggest that RIPoC protects the brain against global cerebral I/R injury and that this neuroprotection is mediated by up-regulating eNOS through the PI3K/Akt pathway.

The present study examines whether human umbilical tissue-derived cells (hUTC) have a neuro-restorative effect and improve functional recovery after intracerebral hemorrhage (ICH) in rats.Primary ICH was induced in male Wistar rats by stereotactic injection of 100μL of autologous blood into the striatal region adjacent to the subventricular zone. Briefly, the rats were randomly divided into six groups, each group was intravenously injected either with 2mL phosphate-buffered saline (PBS) or 3million hUTC in PBS at 1, 3 or 7days after ICH (n=8/group). To evaluate neurological functional outcome, each animal was subjected to the modified neurological severity score (mNSS) and corner turn tests at different time points after ICH. At four weeks post treatment, each group was anesthetized intraperitoneally, sacrificed, and brain tissues were processed histologically. Immunohistochemistry was employed to measure vascularity (vWF), neurogenesis (BrdU TUJ1, DCX and NeuN), synaptogenesis (synaptophysin) and apoptosis (TUNEL).The hUTC-treated animals showed significantly improved neurological functional outcomes as assessed by mNSS and corner turn tests at 14, 21 and 28days post-injection in each treatment group (P0.05) as compared to the PBS controls. Animals treated with hUTC were seen to have significantly increased cell proliferation, vascularity and synaptogenesis, as well as reduced apoptosis in the hematoma rim compared to the corresponding control group (P0.05).Intravenously infused hUTC have a beneficial effect after experimental ICH by functional and histochemical measurements of neural cell proliferation and synaptogenesis in the ICH border zone. This brain region also shows correlative evidence of neuronal recovery with increased vascularity.

Progressive neurodegeneration following traumatic brain injury (TBI) involves the Fas and TNF-receptor1 protein systems which have been implicated in mediating delayed cell death. In this study, we used two approaches to assess whether inhibition of these pathways reduced secondary brain damage and neurological deficits after TBI. Firstly, we investigated whether the expression of non-functional Fas in lpr mice subjected to TBI altered tissue damage and neurological outcome. Compared to wild-type, lpr mice showed improved neurological deficit (p=0.0009), decreased lesion volume (p=0.017), number of TUNEL+ cells (p=0.011) and caspase-3+ cells (p=0.007). Changes in cellular inflammation and cytokine production were also compared between mouse strains. Accumulation of macrophages/microglia occurred earlier in lpr mice, likely due to enhanced production of the chemotactic mediators IL-12(p40) and MCP-1 (p

Paeonol(2′-hydroxy-4′-methoxyacetophenone;1-(2-hydroxy-4-methoxyphenyl)ethan-1-one) is a constituent of the bark of the Moutan Cortex (Paeonia suffruticosa). This bark has been used as a traditional Chinese medicine and is reputed to possess a broad range of therapeutic properties probably by virtue of its anti-inflammatory and free radical scavenging properties. The effects of paeonol on a variety of biochemical and behavioral parameters were studied in rat brain in rat brain after experimental animals had been subjected to an intra-hippocampal injection of amyloid peptide, Aβ1–42. Sprague–Dawley rats were randomly divided into groups: saline, sham operated, β-amyloid (Aβ)-injected (intended to model Alzheimer's disease, (AD), and a group receiving both injected amyloid peptide and paeonol. Forty days after intra-hippocampal injection, H&E staining revealed that the lesions in the paeonol-treated group were significantly less than the untreated group. Levels of cytochrome oxidase and α-actin, determined immunohistochemically, were elevated in the paeonol treated group relative to the group receiving amyloid peptide alone. TUNEL staining revealed more apoptotic cells in the walls of the cerebral vascular elements in the AD model group than in the paeonol group. The paeonol-treated group also showed improvement in behavioral indices of learning relative to the group receiving Aβ1–42 alone, as judged using a Y-type electric maze. Treatment with paeonol can protect against many of the alterations resulting from administration of Aβ1–42. in a rat model of AD. These include morphological, biochemical and behavioral changes. Paeonol is a possible therapeutic measure in slowing down the pathogenic processes associated with AD.

One of the major complications after subarachnoid hemorrhage (SAH) is angiographic vasospasm in the large arteries at the base of the brain. However, a clinical trial of clazosentan demonstrated a 65% relative risk reduction in angiographic vasospasm but no effect on mortality or clinical outcome, raising questions about the role of angiographic vasospasm played in outcome after SAH. The purpose of this study was to determine if reducing or reversing angiographic vasospasm with clazosentan reduced other secondary complications such as microthromboembolism, loss of long-term potentiation (LTP) and neuronal cell death in a rat model of SAH. SAH in rats was created by injection of 300 μl non-heparinized autologous blood into the pre-chiasmatic cistern. Clazosentan, 10mg/kg bolus, or vehicle control was administered 1h after SAH intravenously, followed by a continuous infusion (1mg/kg/h) into the jugular vein using an osmotic pump. Rats treated with clazosentan had less large-artery vasospsam compared to vehicle-treated controls. However, clazosentan did not prevent the formation of microthromboemboli, neuronal cell death and degeneration and loss of LTP, suggesting there is a dissociation between large-artery angiographic vasospasm and other secondary complications of SAH. This result suggests that alleviation of angiographic vasospasm alone may not be sufficient to prevent other secondary complications or that off-target drug effects after systemic administration of clazosentan counteract the beneficial effects on angiographic vasospasm.

We have designed a clinically relevant model of perinatal asphyxia providing intrapartum hypoxia in rats. On gestation day 22 SD rats were anesthetized and the uterine horns were exteriorized and placed in a water bath at 37 °C for up to 20 min. After this, pups were delivered from the uterus and manually stimulated to initiate breathing in an incubator at 37 °C for 1 h in air. Brains were harvested and stained with cresyl violet, caspase-3, and TUNEL to detect morphological and apoptotic changes on postnatal days (PND) 1, 3, and 7. Separate cohorts were maintained until PND 50 and tested for learning and memory using Morris water maze (WM). Survival rate was decreased with longer hypoxic time, and 100% mortality was noted when hypoxia time was beyond 18 min. Apoptosis was increased with the duration of hypoxia with neuronal loss and cell shrinkage in the CA1 of hippocampus. The time taken for the juveniles to locate the hidden platform during WM was increased in animals subjected to hypoxia. These data demonstrate that perinatal ischemic injury leads to neuronal death in the hippocampus and long-lasting cognitive dysfunction. This model mimics hypoxic ischemic encephalopathy in humans and may be appropriate for investigating therapeutic interventions.

Recently, it has been suggested that anesthetic agents may have neuroprotective potency. The notion that anesthetic agents can offer neuroprotection remains controversial. Propofol, which is a short-acting intravenous anesthetic agent, may have potential as a neuroprotective agent. In this study, we tried to determine whether propofol affected the viability of human neuroblastoma SH-SY5Y cells by using the MTT assay. Surprisingly, our results showed that propofol at a dose of 1–10 μM could improve cell proliferation. However, at higher doses (200 μM), propofol appears to be cytotoxic. On the other hand, propofol could up-regulate the expression of key proteins involved in neuroprotection including B-cell lymphoma 2 at a dose range of 1–10 μM, activation of phospho-serine/threonine protein kinase at a dose range of 0.5–10 μM, and activation of phospho-extracellular signal-regulated kinases at a dose range of 5–10 μM. Similarly, we demonstrate that propofol (10 μM) could elevate protein levels of heat shock protein 90 and heat shock protein 70. Therefore, we choose to utilize a 10 μM concentration of propofol to assess neuroprotective activities in our studies. In the following experiments, we used dynorphin A to generate cytotoxic effects on SH-SY5Y cells. Our data indicate that propofol (10 μM) could inhibit the cytotoxicity in SH-SY5Y cells induced by dynorphin A. Furthermore, propofol (10 μM) could decrease the expression of the p-P38 protein as well. These data together suggest that propofol may have the potential to act as a neuroprotective agent against various neurologic diseases. However, further delineation of the precise neuroprotective effects of propofol will need to be examined.

Cleaved caspase-3 (CC3) is well known as an executioner protease of apoptosis following brain ischemia. However, an increasing body of evidence suggests several non-apoptotic functions of CC3. To improve our understanding of the relation between cell death-related and non-adverse effects of postischemic caspase-3 activation, we examined the spatiotemporal distribution and identity of CC3-positive cells at days 2, 3 and 4 after permanent middle cerebral artery occlusion in rats. The lacking colocalization of CC3 and TUNEL staining indicated, that CC3 expression was predominantly non-apoptotic. Nuclear CC3 expression was frequently found to be colocalized with GFAP-positive astrocytes within the tissue adjacent to the infarct, whereas cytoplasmatic CC3 expression occurred solely in the lesion. Multiple fluorescence labeling revealed costaining of cytoplasmatic CC3 with markers directed against astrocytes, macrophages/microglia and supposedly pericytes. Our findings suggest that CC3 expression was predominantly associated with cellular responses to stroke such as reactive astrogliosis and the infiltration of macrophages.

Recent studies show helium may be one kind of neuroprotective gas. This study aimed to examine the short and long-term neuroprotective effects of helium preconditioning in an established neonatal cerebral hypoxia-ischemia (HI) model. Seven-day-old rat pups were subjected to left common carotid artery ligation and then 90 min of hypoxia (8% oxygen at 37°C). The preconditioning group inhaled 70% helium-30% oxygen for 5 min three times with an interval of 5 min 24h before HI insult. Pups were decapitated 24h after HI and brain morphological injury was assessed by 2,3,5-triphenyltetrazolium chloride (TTC) staining, Nissl and TUNEL staining. Caspase-3 activity in the brain was measured. Five weeks after HI, postural reflex testing and Morris water maze testing were conducted. Our results showed that helium preconditioning reduced the infarct ratio, increased the number of survival neurons, and inhibited apoptosis at the early stage of HI insult. Furthermore, the sensorimotor function and the cognitive function were improved significantly in rats with helium preconditioning. The results indicate that helium preconditioning attenuates HI induced brain injury.

Chitooligosaccharides (COSs), the biodegradation product of chitosan, possess a wide range of biological activities. In this study, we investigated the influences of COSs on primary cultured cortical neurons exposed to glucose deprivation (GD). The cell viability assessment by MTT assay, in couple with cell apoptosis analysis by Hoechst 33342 and TUNEL staining, indicated that GD-induced cell apoptosis in cultured cortical neurons was attenuated by COSs co-treatment in a dose-dependent manner. Light micrography following tetramethylrhodamine methyl ester staining revealed that COSs protected cultured cortical neurons from GD insult through the stabilization of mitochondrial membrane potentials. COSs co-treatment also led to the increase in Bcl-2/Bax protein ratio and the inhibition of caspase-3 activation in cultured cortical neurons exposed to GD insult. We further found that COSs were able to transiently cause the activation of Akt and ERK1/2 proteins, and anti-apoptotic effects of COSs could be blocked by chemical inhibition of PI3K and MEK. Taken together, the results suggest that COSs hold a promise to serve as a potential neuroprotective agent for treating cerebral ischemic stroke and neurodegenerative diseases.

Cytokinetics regulating cell cycle division can be modulated by several endogenous factors. EAE (experimental autoimmune encephalomyelitis) increases proliferation of progenitor cells in the subventricular zone (SVZ). Using cumulative and single S phase labeling with 5-bromo-2-deoxyuridine, we examined cell cycle kinetics of neural progenitor cells in the SVZ after EAE. 20% of the SVZ cell population was proliferating in adjuvant control rats. However, EAE significantly increased them up to 27% and these cells had a cell cycle length (TC) of 15.6h, significantly (P0.05) shorter than the 19 h TC in non EAE SVZ cells. Few TUNEL (+) cells were detected in the SVZ cells of adjuvant controls. EAE increased (P0.05) TUNEL (+) nuclei in SVZ suggesting early stage progenitor cell death. Cell cycle phase analysis revealed that EAE substantially shortened the length of the G1 phase (9.6h) compared with the G1 phase of 12.25 h in adjuvant control SVZ cells (P0.05). This reduction in G1 contributes to EAE-induced reduction of TC because no significant changes were detected on the length of S, G2 and M phases between the two groups. Our results show a surge in proliferating progenitor cells in the SVZ with concomitant increase in apoptotic cell death after EAE. Furthermore, increase in the SVZ proliferation contributes to EAE-induced neurogenesis and this increase is regulated by shortening the G1 phase. Our investigation suggests the activation of quiescent cells in SVZ to generate actively proliferating progenitors. Moreover, the increase in the cell death in proliferating population may contribute towards negative regulation of proliferative cell number and hence diminished regenerative capacity of CNS following EAE.

Endoplasmic reticulum (ER) stress has been implicated in the pathology of cerebral ischemia. During prolonged period of stress or when the adaptive response fails, apoptotic cell death ensues. Cerebral ischemic postconditioning (Postcond) has been shown to reduce cerebral ischemia/reperfusion (I/R) injury in both focal and global cerebral ischemia model. However, the mechanism remains to be understood. This study aimed to elucidate whether Postcond attenuates brain I/R damage by suppressing ER stress-induced apoptosis and if the phosphatidylinositol-3kinase/Akt (PI3K/Akt) pathway is involved. A focal cerebral ischemia rat model was used in the study. Rat brain infarct size and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) positive cells in ischemic penumbra were assessed after reperfusion of the brain. The expressions of C/EBP-homologous protein (CHOP), caspase-12, glucose-regulated protein 78 (GRP78) and the phosphorylation of Akt (Ser473) in ischemic penumbra were measured after reperfusion. Our results showed that Postcond significantly attenuated brain I/R injury, as shown by reduction in infarct size, cell apoptosis, CHOP expression, caspase-12 activation and increase in GRP78 expression. LY294002, a phosphoinositide 3-kinase inhibitor, increased the number of TUNEL-positive cells suppressed by Postcond in penumbra. In addition, LY294002 diminished the effect of Postcond on the activation of CHOP, caspase-12 and GRP78. These results suggest that Postcond protects brain from I/R injury by suppressing ER stress-induced apoptosis and PI3K/Akt pathway is involved.

Mesenchymal stem cells (MSCs) have been successfully used for the treatment of experimental stroke. However, the neurorestorative mechanisms by which MSCs improve neurological functional recovery are not fully understood. Endogenous cell proliferation in the subventricular zone (SVZ) after stroke is well known, but most of newly formed cells underwent apoptosis. In the present study, we tested the hypothesis that neurotrophic factors secreted by human bone marrow-derived MSCs (hBMSCs) promote endogenous neurogenesis, reduce apoptosis, and improve functional recovery. Adult rats subjected to 2-h middle cerebral artery occlusion (MCAO) were transplanted with hBMSCs or saline into the ipsilateral brain parenchyma at 3 days after ischemia. There was a significant recovery of behavior in the hBMSCs-treated rats beginning at 14 days after MCAO compared with the control animals. Higher levels of brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and vascular endothelial growth factor (VEGF) were detected in the hBMSCs-treated rat brain than the control. Human BMSCs treatment also enhanced endogenous cell proliferation both in the SVZ and in the subgranular zone (SGZ) of the hippocampus. In addition, more neuronal progenitor cells migrated from the SVZ to the ischemic boundary zone (IBZ) and differentiated into mature neurons with less apoptosis in rats treated with hBMSCs. Overall, these data suggest an essential role for hBMSCs in promoting endogenous neurogenesis, protecting newly formed cells, and improving functional recovery after ischemia in rats.

Changes in gene expression have been measured 24h after injury to mammalian spinal cords that can and cannot regenerate. In opossums there is a critical period of development when regeneration stops being possible: at 9 days postnatal cervical spinal cords regenerate, at 12 days they do not. By the use of marsupial cDNA microarrays, we detected 158 genes that respond differentially to injury at the two ages critical for regeneration. For selected candidates additional measurements were made by real-time PCR and sites of their expression were shown by immunostaining. Candidate genes have been classified so as to select those that promote or prevent regeneration. Up-regulated by injury at 8 days and/or down-regulated by injury at 13 days were genes known to promote growth, such as Mitogen-activated protein kinase kinase 1 or transcription factor TCF7L2. By contrast, at 13 days, up-regulation occurred of inhibitory molecules, including annexins, ephrins, and genes related to apoptosis and neurodegenerative diseases. Certain genes such as calmodulin 1 and NOGO, changed expression similarly in animals that could and could not regenerate without any additional changes in response to injury. These findings confirmed and extended changes of gene expression found in earlier screens on 9 and 12 ay preparations without lesions and provide a comprehensive list of genes that serve as a basis for testing how identified molecules, singly or in combination, promote and prevent central nervous system regeneration.

Although recent results suggest that GluR6 serine phosphorylation plays a prominent role in brain ischemia/reperfusion-mediated neuronal injury, little is known about the precise mechanisms regulating GluR6 receptor phosphorylation. Our present study shows that the assembly of the GluR6–PSD95–CaMKII signaling module induced by brain ischemia facilitates the serine phosphorylation of GluR6 and further induces the activation of c-Jun NH2-terminal kinase JNK. More important, a selective CaMKII inhibitor KN-93 suppressed the increase of the GluR6–PSD95–CaMKII signaling module assembly and GluR6 serine phosphorylation as well as JNK activation. Such effects were similar to be observed by NMDA receptor antagonist MK801 and L-type Ca2+ channel (L-VGCC) blocker Nifedipine. These results demonstrate that NMDA receptors and L-VGCCs depended-CaMKII functionally modulated the phosphorylation of GluR6 via the assembly of GluR6–PSD95–CaMKII signaling module in cerebral ischemia injury.

dl-3-n-Butylphthalide (NBP) has shown cytoprotective effects in animal models of stroke and has passed clinical trails as a therapeutic drug for stroke in China. Hence, as a potential clinical treatment for stroke, understanding the mechanism(s) of action of NBP is essential. This investigation aimed to delineate the cellular and molecular mechanism of NBP protection in neuronal cultures and in the ischemic brain. NBP (10 M) attenuated serum deprivation-induced neuronal apoptosis and the production of reactive oxygen species (ROS) in cortical neuronal cultures. Adult male 129 S2/sv mice were subjected to permanent occlusion of the middle cerebral artery (MCA). NBP (100 mg/kg, i.p.) administrated 2 hrs before or 1 hr after ischemia reduced ischemia-induced infarct formation, attenuated caspase-3 and caspase-9 activation in the ischemic brain. TUNEL-positive cells and mitochondrial release of cytochrome c and apoptosis-inducing-factor (AIF) in the penumbra region were reduced by NBP. The pro-apoptotic signaling mediated by phospho-JNK and p38 expression was down-regulated by NBP treatment in vitro and in vivo. It is suggested that NBP protects against ischemic damage via multiple mechanisms including mitochondria associated caspase-dependent and -independent apoptotic pathways. Previous and current studies and recent clinical trials encourage exploration of NBP as a neuroprotective drug for the treatment of ischemic stroke.

Monosialotetrahexosy-1 ganglioside (GM1) has been shown to reduce brain damage induced by cerebral ischemia. The objective of this study is to determine whether GM1 is able to ameliorate hyperglycemia-exacerbated ischemic brain damage in hyperglycemia-recruited areas such as the hippocampal CA3 sub regions and the cingulated cortex. Histologic stainings of Haematoxylin and Eosin, Nissl body, the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) and phospho-ERK1/2 were performed on brain sections that has been subjected to 15 minutes of forebrain ischemia with reperfusion of 0-, 1-, 3-, and 6- hours in normoglycemic, hyperglycemic and GM1-pretreated hyperglycemic groups. The results showed that GM1 ameliorated ischemic neuronal injuries in the CA3 area and cingulated cortex of the hyperglycemic animals after ischemia and reperfusion. Immunohistochemistry of phospho-ERK1/2 revealed that the neuroprotective effects of GM1 were associated with suppression of phospho-ERK1/2. The results suggest that GM1 attenuates diabetic-augmented ischemic neuronal injuries probably through suppression of ERK1/2 phosphorylation.

The study was aimed to investigate the protective effects of rosuvastatin on spinal cord ischemia in rats and to determine the effects of this agent on the expressions of nitric oxide synthase (NOS). Spinal cord ischemia was induced in male Sprague–Dawley rats by occluding the descending thoracic aorta. Experimental groups (n = 30 per group) were as follows: sham operation, control (receiving only normal saline), rosuvastatin (5 mg/kg/day for 10 days before occlusion), and rosuvastatin-mevalonate (5 mg/kg/day rosuvastatin and 5 mg/kg/day mevalonate for 10 days before occlusion). Neurological function was assessed at 6, 12, 24, 48, and 72 h after reperfusion. After 72 h reperfusion, spinal cords were harvested for 2,3,5,-triphenyltetrazolium chloride (TTC) staining, TUNEL staining, and nitric oxide (NO) assay. Immunohistochemistry, reverse transcription polymerase chain reaction and western blot were performed to determine the expressions of inducible, endothelial, and neuronal NOS (iNOS, eNOS, and nNOS) in rats with spinal cord ischemia. Spinal cord ischemia thus induced was marked by neurological dysfunction, spinal infarction, and neural cell apoptosis in animals. The results show that rosuvastatin significantly reduced the motor disturbance and the volume of infarctions and attenuated apoptotic neural cells death in the treated rats. Treatment with rosuvastatin remarkably decreased the NO level in spinal cord tissue. In addition, rosuvastatin inhibited iNOS mRNA and protein expression and increased eNOS mRNA and protein expression. However, rosuvastatin had no influence on nNOS mRNA and protein expression. Administrations of mevalonate completely reversed the changes caused by rosuvastatin. These results indicate that rosuvastatin can protect rat spinal cord against ischemia injury by modulation of NOS expressions.

Many experiments support the notion that augmentation of neurotrophic factors' (NTFs) activity, especially glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) could prevent or halt the progress of neurodegeneration in Parkinson's disease (PD). However, application of NTFs as therapeutic agents for PD is hampered by the difficulty in delivering them to specific brain regions safely and effectively. Another potential strategy is to stimulate the endogenous expression of NTFs. In this study, we investigated the effects of Echinacoside (ECH), a monomer extracted from herbs, on rescuing dopaminergic function in 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-lesioned mice. We found that oral administration of ECH (30 mg/kg/day for 14 days) to MPTP-treated mice, commencing after impairment of the nigrstriatal system, suppressed the reduction of nigral dopaminergic neurons, striatal fibers, dopamine and dopamine transporter to 134.24%, 203.17%, 147.25% and 154.72 of MPTP-lesioned animals respectively (p

Mesenchymal stem cell (MSC) transplantation has been reported to improve neurologic function after ischemic injury. However, the detailed mechanisms by which MSCs promote functional recovery are not fully understood. Interleukin-10 (IL-10) is a well-known anti-inflammatory cytokine with neuroprotective effects with respect to brain injury. In this study, a non-human primate ischemia model was used to test the hypothesis that transplanted human bone-marrow-derived MSCs (hBMSCs) exert a neuroprotective effects on cerebral ischemia and upregulate IL-10 expression. We also assessed neuronal apoptosis and astroglial activity in the area around the ischemic lesion and proliferating cells in the subventricular zone (SVZ). Results showed that hBMSC transplantation in ischemic tissues improved the neurological functions and induced an increase in IL-10 expression. In addition, neuronal apoptosis and astroglial activity in the peri-ischemic area decreased, and the number of proliferating cells in the SVZ increased. These results provide a novel therapeutic strategy for improving neurologic function after cerebral ischemia.

Neural changes occur in the dam during gestation, and brain size has been shown to decrease across pregnancy in humans as well as rodents. In this study, we monitored neuronal damage, cell proliferation and neuroblast differentiation in the hippocampal dentate gyrus (DG) at age-matched virgin control (17- to 18-week-old), gestation day (GD) 14.5, 16.5 and 18.5 (17- to 18-week-old dams), using NeuN for mature neurons, terminal deoxynucleotidyl dUTP nick-end labeling (TUNEL) and Fluoro-Jade B (F-J B) for neuronal death, Ki67 for cell proliferation and doublecortin (DCX) for neuroblast differentiation in C57BL/6 mice. There were no significant differences in NeuN-immunoreactive ((+)) neurons between the age-matched control and gestating groups. TUNEL or F-J B positive neurons were rarely detected in the DG in all the groups. Ki67(+) cell proliferation was significantly decreased in the subgranular zone of the dentate gyrus (SZDG) at GD16.5. In addition, DCX(+) neuroblasts with/without tertiary dendrites were decreased in the SZDG with gestation by GD16.5. However, in the GD18.5 group, the number of Ki67(+) nuclei and DCX(+) neuroblasts with/without tertiary dendrites was slightly increased compared to that observed at GD16.5. DCX protein levels were low at GD16.5, and thereafter slightly increased. These results suggest that cell proliferation and neuroblast differentiation in DG of the hippocampus is decreased during gestation.

This study investigated whether endoplasmic reticulum (ER) stress induced retinal ganglion cell (RGC) death in chronic ocular hypertension, one of the RGC death mechanisms, using an experimental glaucoma rat model. Glaucoma was induced in adult male Sprague-Dawley rats by cauterizing three episcleral veins. The intraocular pressure (IOP) remained elevated in the cauterized eyes for the 8-week experiment, whereas it was not elevated in the contralateral control eyes. The average number of RGCs decreased significantly, and TUNEL-positive cells were detected in the ganglion cell layer. In western blotting, Bip, the phosphorylated form of PKR (p-PERK), and C/EBP-homologous protein (CHOP) were significantly expressed at 1 or 2 weeks, and this persisted throughout the 8-week experiment. Phosphorylated eukaryotic initiation factor 2 (p-eIF2alpha) began to increase at 1 week, was sustained through 4 weeks, and decreased slightly at 8 weeks. In cauterized eyes, strong p-PERK and CHOP immunoreactivity was observed in ganglion cells after 8 weeks of IOP elevation. Taken together, in the experimental chronic glaucoma model, ER stress is involved in RGC death, and the PERK-p-eIF2alpha-CHOP pathway plays a role in the RGC apoptosis associated with ER stress. This might be a good therapeutic target to protect RGCs from ER stress injury in glaucoma.

Recent studies revealed the neuroprotective effects of epigallocatechin gallate (EGCG) on a variety of neural injury .The purpose of this study was to determine the effects of EGCG on the tissue protection and behavioral improvement after spinal cord injury (SCI). Rats were randomly divided into four groups of 18 rats each as follows: sham-operated group, trauma group, and EGCG treatment groups (50 mg/kg, i.p., immediately and 1 hour after SCI). Spinal cord samples were taken 24 hours after injury and studied for determination of malodialdehyde (MDA) levels, immunohistochemistry of Bax and Bcl-2, and TUNEL reaction. Behavioral testing was performed weekly up to 6 weeks post-injury. Then, the rats were euthanized for histopathological assessment. The results showed that MDA levels were significantly decreased in EGCG treatment groups. Greater Bcl-2 and attenuated Bax expression could be detected in the EGCG-treated rats. EGCG significantly reduced TUNEL-positive rate. Also, EGCG significantly reduced the percentage of lesion area and improved behavioral function than the trauma group. On the basis of these findings, we propose that EGCG may be effective in protecting rat spinal cord from secondary injury.

Although intravenous delivery of mesenchymal stem cells (MSCs) prepared from adult bone marrow reduces infarction size and ameliorates functional deficits in rat middle cerebral artery occlusion models, there are few reports of MSC treatment in global cerebral ischemia. We utilized a global cerebral ischemia model induced by arresting the heart with a combination of hypovolemia and intracardiac injections of a cold potassium chloride solution in order to study the potential therapeutic benefits of human mesenchymal stem cells (hMSCs) on global cerebral ischemia. hMSCs were intravenously injected into the rats 3 h after resuscitation from cardiac arrest. The effects on structural and functional outcome of hMSC were assessed at 5 h and 1, 3, and 7 days using magnetic resonance spectroscopy (MRS), histology, and cognitive functional analysis. Intravenous delivery of hMSCs reduced the Lac/Cr ratios, nuclear DNA fragmentation, neuronal loss, and elicited functional improvement compared with the control sham group. Enzyme-linked immunosorbent assay (ELISA) of the hippocampus revealed an increase in BDNF in hMSC-treated group. These data suggest that intravenous delivery of hMSC may have a therapeutic effect in global cerebral ischemia.