Science.gov

Sample records for cerebral neuron apoptosis

  1. Tocilizumab inhibits neuronal cell apoptosis and activates STAT3 in cerebral infarction rat model.

    PubMed

    Wang, Shaojun; Zhou, Jun; Kang, Weijie; Dong, Zhaoni; Wang, Hezuo

    2016-01-15

    Cerebral infarction is a severe hypoxic ischemic necrosis with accelerated neuronal cell apoptosis in the brain. As a monoclonal antibody against interleukin 6, tocilizumab (TCZ) is widely used in immune diseases, whose function in cerebral infarction has not been studied. This study aims to reveal the role of TCZ in regulating neuronal cell apoptosis in cerebral infarction. The cerebral infarction rat model was constructed by middle cerebral artery occlusion and treated with TCZ. Cell apoptosis in hippocampus and cortex of the brain was examined with TUNEL method. Rat neuronal cells cultured in oxygen-glucose deprivation (OGD) conditions and treated with TCZ were used to compare cell viability and apoptosis. Apoptosis-related factors including B-cell lymphoma extra large (Bcl-xL) and Caspase 3, as well as the phosphorylated signal transducer and activator of transcription 3 (p-STAT3) in brain cortex were analyzed from the protein level. Results indicated that TCZ treatment could significantly prevent the promoted cell apoptosis caused by cerebral infarction or OGD (P < 0.05 or P < 0.01). In brain cortex of the rat model, TCZ up-regulated Bcl-xL and down-regulated Caspase 3, consistent with the inhibited cell apoptosis. It also promoted tyrosine 705 phosphorylation of STAT3, which might be the potential regulatory mechanism of TCZ in neuronal cells. This study provided evidence for the protective role of TCZ against neuronal cell apoptosis in cerebral infarction. Based on these fundamental data, TCZ is a promising option for treating cerebral infarction, but further investigations on related mechanisms are still necessary.

  2. Tocilizumab inhibits neuronal cell apoptosis and activates STAT3 in cerebral infarction rat model

    PubMed Central

    Wang, Shaojun; Zhou, Jun; Kang, Weijie; Dong, Zhaoni; Wang, Hezuo

    2016-01-01

    Cerebral infarction is a severe hypoxic ischemic necrosis with accelerated neuronal cell apoptosis in the brain. As a monoclonal antibody against interleukin 6, tocilizumab (TCZ) is widely used in immune diseases, whose function in cerebral infarction has not been studied. This study aims to reveal the role of TCZ in regulating neuronal cell apoptosis in cerebral infarction. The cerebral infarction rat model was constructed by middle cerebral artery occlusion and treated with TCZ. Cell apoptosis in hippocampus and cortex of the brain was examined with TUNEL method. Rat neuronal cells cultured in oxygen-glucose deprivation (OGD) conditions and treated with TCZ were used to compare cell viability and apoptosis. Apoptosis-related factors including B-cell lymphoma extra large (Bcl-xL) and Caspase 3, as well as the phosphorylated signal transducer and activator of transcription 3 (p-STAT3) in brain cortex were analyzed from the protein level. Results indicated that TCZ treatment could significantly prevent the promoted cell apoptosis caused by cerebral infarction or OGD (P < 0.05 or P < 0.01). In brain cortex of the rat model, TCZ up-regulated Bcl-xL and down-regulated Caspase 3, consistent with the inhibited cell apoptosis. It also promoted tyrosine 705 phosphorylation of STAT3, which might be the potential regulatory mechanism of TCZ in neuronal cells. This study provided evidence for the protective role of TCZ against neuronal cell apoptosis in cerebral infarction. Based on these fundamental data, TCZ is a promising option for treating cerebral infarction, but further investigations on related mechanisms are still necessary. PMID:26773188

  3. Tanshinone inhibits neuronal cell apoptosis and inflammatory response in cerebral infarction rat model.

    PubMed

    Zhou, Liang; Zhang, Jie; Wang, Chao; Sun, Qiangsan

    2017-06-01

    We aimed to investigate the effect and mechanisms of tanshinone (TSN) IIA in cerebral infarction. The cerebral infarction rat model was established by middle cerebral artery occlusion (MCAO). After pretreatment with TSN, cerebral infarct volume, cerebral edema, and neurological deficits score were evaluated, as well as cell apoptosis in hippocampus and cortex of the brain was examined with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and the levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) were determined by Enzyme-Linked Immunosorbent Assay (ELISA). In addition, rat primary neuronal cells were isolated and cultured in oxygen-glucose deprivation (OGD) conditions. After pretreatment with TSN, cell viability and apoptosis were observed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry analysis, respectively. The expressions of Bax and B-cell lymphoma 2 (Bcl-2) were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blotting. Compared with untreated cerebral infarction rat, TSN treatment significantly reduced cerebral infarct volume, cerebral edema, and neurological deficits score ( P < 0.05). Cell apoptosis as well as the levels of IL-6, TNF-α, and CRP in hippocampus and cortex of cerebral infarction rat were inhibited after pretreatment with TSN ( P < 0.05). Furthermore, TSN remarkably increased cell viability and inhibited cell apoptosis ratio ( P < 0.05) in OGD-induced rat neuronal cells. Besides, TSN significantly downregulated the expression of Bax and upregulated Bcl-2 ( P < 0.05). TSN IIA has a preventive effect on cerebral infarction by inhibiting neuronal cell apoptosis and inflammatory response in vitro and in vivo.

  4. Effect of isoflurane on neuronal apoptosis in rats subjected to focal cerebral ischemia.

    PubMed

    Kawaguchi, Masahiko; Drummond, John C; Cole, Daniel J; Kelly, Paul J; Spurlock, Mark P; Patel, Piyush M

    2004-03-01

    Although isoflurane can reduce ischemic neuronal injury after short postischemic recovery intervals, this neuroprotective efficacy is not sustained. Neuronal apoptosis can contribute to the gradual increase in infarct size after ischemia. This suggests that isoflurane, although capable of reducing early neuronal death, may not inhibit ischemia-induced apoptosis. We investigated the effects of isoflurane on markers of apoptosis in rats subjected to focal ischemia. Fasted Wistar-Kyoto rats were anesthetized with isoflurane and randomly allocated to awake (n = 40) or isoflurane (n = 40) groups. Animals in both groups were subjected to focal ischemia by filament occlusion of the middle cerebral artery for 70 min. Pericranial temperature was servo-controlled at 37 degrees C +/- 0.2 degrees C throughout the experiment. In the awake group, isoflurane was discontinued and the animals were allowed to awaken. In the isoflurane group, isoflurane anesthesia was maintained at 1.5 MAC (minimum alveolar anesthetic concentration). Animals were killed 7 h, 1 day, 4 days, or 7 days after reperfusion (n = 10/group/time point). The area of cerebral infarction was measured by image analysis in a hematoxylin and eosin stained section. In three adjacent sections, apoptotic neurons were identified by TUNEL staining and immunostaining for active caspase-9 and caspase-3. Infarct size was smaller in the isoflurane group than the awake group 7 h, 1 day, and 4 days after reperfusion (P < 0.05). However, this difference was absent 7 days after reperfusion. The number of apoptotic (TUNEL, caspase-3, and caspase-9 positive) cells 1 day after ischemia was significantly more in the awake versus isoflurane group. After a recovery period of 4 or 7 days, the number of apoptotic cells in the isoflurane group was more than in the awake group. After 7 days, the number of caspase-3 and -9 positive neurons was more in the isoflurane group (P < 0.05). The data indicate that isoflurane delays but does not

  5. Exercise inhibits neuronal apoptosis and improves cerebral function following rat traumatic brain injury.

    PubMed

    Itoh, Tatsuki; Imano, Motohiro; Nishida, Shozo; Tsubaki, Masahiro; Hashimoto, Shigeo; Ito, Akihiko; Satou, Takao

    2011-09-01

    Exercise is reported to inhibit neuronal apoptotic cell death in the hippocampus and improve learning and memory. However, the effect of exercise on inhibition of neuronal apoptosis surrounding the area of damage after traumatic brain injury (TBI) and the improvement of cerebral dysfunction following TBI are unknown. Here, we investigate the effect of exercise on morphology and cerebral function following TBI in rats. Wistar rats received TBI by a pneumatic controlled injury device were randomly divided into two groups: (1) non-exercise group and (2) exercise group. The exercise group ran on a treadmill for 30 min/day at 22 m/min for seven consecutive days. Immunohistochemical and behavioral studies were performed following TBI. The number of single-stranded DNA (ssDNA)-positive cells around the damaged area early after TBI was significantly reduced in the exercise group compared with the non-exercise group (P < 0.05). Furthermore, most ssDNA-positive cells in the non-exercise group co-localized with neuronal cells. However, in the exercise group, a few ssDNA-positive cells co-localized with neurons. In addition, there was a significant increase in neuronal cell number and improvement in cerebral dysfunction after TBI in the exercise group compared with the non-exercise group (P < 0.05). These results indicate that exercise following TBI inhibits neuronal degeneration and apoptotic cell death around the damaged area, which results in improvement of cerebral dysfunction. In summary, treadmill running improved cerebral dysfunction following TBI, indicating its potential as an effective clinical therapy. Therefore, exercise therapy (rehabilitation) in the early phase following TBI is important for recuperation from cerebral dysfunction.

  6. Azadirachta indica ethanolic extract protects neurons from apoptosis and mitigates brain swelling in experimental cerebral malaria

    PubMed Central

    2013-01-01

    Background Cerebral malaria is a rapidly developing encephalopathy caused by the apicomplexan parasite Plasmodium falciparum. Drugs currently in use are associated with poor outcome in an increasing number of cases and new drugs are urgently needed. The potential of the medicinal plant Azadirachta indica (Neem) for the treatment of experimental cerebral malaria was evaluated in mice. Methods Experimental cerebral malaria was induced in mice by infection with Plasmodium berghei ANKA. Infected mice were administered with Azadirachta indica ethanolic extract at doses of 300, 500, or 1000 mg/kg intraperitoneally (i.p.) in experimental groups, or with the anti-malarial drugs chloroquine (12 mg/kg, i.p.) or artemether (1.6 mg/kg, i.p.), in the positive control groups. Treatment was initiated at the onset of signs of brain involvement and pursued for five days on a daily basis. Mice brains were dissected out and processed for the study of the effects of the extract on pyramidal cells’ fate and on markers of neuroinflammation and apoptosis, in the medial temporal lobe. Results Azadirachta indica ethanolic extract mitigated neuroinflammation, decreased the severity of brain oedema, and protected pyramidal neurons from apoptosis, particularly at the highest dose used, comparable to chloroquine and artemether. Conclusions The present findings suggest that Azadirachta indica ethanolic extract has protective effects on neuronal populations in the inflamed central nervous system, and justify at least in part its use in African and Asian folk medicine and practices. PMID:23984986

  7. Azadirachta indica ethanolic extract protects neurons from apoptosis and mitigates brain swelling in experimental cerebral malaria.

    PubMed

    Bedri, Selma; Khalil, Eltahir A; Khalid, Sami A; Alzohairy, Mohammad A; Mohieldein, Abdlmarouf; Aldebasi, Yousef H; Seke Etet, Paul Faustin; Farahna, Mohammed

    2013-08-29

    Cerebral malaria is a rapidly developing encephalopathy caused by the apicomplexan parasite Plasmodium falciparum. Drugs currently in use are associated with poor outcome in an increasing number of cases and new drugs are urgently needed. The potential of the medicinal plant Azadirachta indica (Neem) for the treatment of experimental cerebral malaria was evaluated in mice. Experimental cerebral malaria was induced in mice by infection with Plasmodium berghei ANKA. Infected mice were administered with Azadirachta indica ethanolic extract at doses of 300, 500, or 1000 mg/kg intraperitoneally (i.p.) in experimental groups, or with the anti-malarial drugs chloroquine (12 mg/kg, i.p.) or artemether (1.6 mg/kg, i.p.), in the positive control groups. Treatment was initiated at the onset of signs of brain involvement and pursued for five days on a daily basis. Mice brains were dissected out and processed for the study of the effects of the extract on pyramidal cells' fate and on markers of neuroinflammation and apoptosis, in the medial temporal lobe. Azadirachta indica ethanolic extract mitigated neuroinflammation, decreased the severity of brain oedema, and protected pyramidal neurons from apoptosis, particularly at the highest dose used, comparable to chloroquine and artemether. The present findings suggest that Azadirachta indica ethanolic extract has protective effects on neuronal populations in the inflamed central nervous system, and justify at least in part its use in African and Asian folk medicine and practices.

  8. Recombinant human erythropoietin increases survival and reduces neuronal apoptosis in a murine model of cerebral malaria

    PubMed Central

    Wiese, Lothar; Hempel, Casper; Penkowa, Milena; Kirkby, Nikolai; Kurtzhals, Jørgen AL

    2008-01-01

    Background Cerebral malaria (CM) is an acute encephalopathy with increased pro-inflammatory cytokines, sequestration of parasitized erythrocytes and localized ischaemia. In children CM induces cognitive impairment in about 10% of the survivors. Erythropoietin (Epo) has – besides of its well known haematopoietic properties – significant anti-inflammatory, antioxidant and anti-apoptotic effects in various brain disorders. The neurobiological responses to exogenously injected Epo during murine CM were examined. Methods Female C57BL/6j mice (4–6 weeks), infected with Plasmodium berghei ANKA, were treated with recombinant human Epo (rhEpo; 50–5000 U/kg/OD, i.p.) at different time points. The effect on survival was measured. Brain pathology was investigated by TUNEL (Terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP)-digoxigenin nick end labelling), as a marker of apoptosis. Gene expression in brain tissue was measured by real time PCR. Results Treatment with rhEpo increased survival in mice with CM in a dose- and time-dependent manner and reduced apoptotic cell death of neurons as well as the expression of pro-inflammatory cytokines in the brain. This neuroprotective effect appeared to be independent of the haematopoietic effect. Conclusion These results and its excellent safety profile in humans makes rhEpo a potential candidate for adjunct treatment of CM. PMID:18179698

  9. Gadd45b prevents autophagy and apoptosis against rat cerebral neuron oxygen-glucose deprivation/reperfusion injury.

    PubMed

    He, Guoqian; Xu, Wenming; Tong, Linyan; Li, Shuaishuai; Su, Shiceng; Tan, Xiaodan; Li, Changqing

    2016-04-01

    Autophagic (type II) cell death has been suggested to play pathogenetic roles in cerebral ischemia. Growth arrest and DNA damage response 45b (Gadd45b) has been shown to protect against rat brain ischemia injury through inhibiting apoptosis. However, the relationship between Gadd45b and autophagy in cerebral ischemia/reperfusion (I/R) injury remains uncertain. The aim of this study is to investigate the effect of Gadd45b on autophagy. We adopt the oxygen-glucose deprivation and reperfusion (OGD/R) model of rat primary cortex neurons, and lentivirus interference used to silence Gadd45b expression. Cell viability and injury assay were performed using CCK-8 and LDH kit. Autophagy activation was monitored by expression of ATG5, LC3, Beclin-1, ATG7 and ATG3. Neuron apoptosis was monitored by expression of Bcl-2, Bax, cleaved caspase3, p53 and TUNEL assay. Neuron neurites were assayed by double immunofluorescent labeling with Tuj1 and LC3B. Here, we demonstrated that the expression of Gadd45b was strongly up-regulated at 24 h after 3 h OGD treatment. ShRNA-Gadd45b increased the expression of autophagy related proteins, aggravated OGD/R-induced neuron cell apoptosis and neurites injury. ShRNA-Gadd45b co-treatment with autophagy inhibitor 3-methyladenine (3-MA) or Wortmannin partly inhibited the ratio of LC3II/LC3I, and slightly ameliorated neuron cell apoptosis under OGD/R. Furthermore, shRNA-Gadd45b inhibited the p-p38 level involved in autophagy, but increased the p-JNK level involved in apoptosis. ShRNA-Gadd45b co-treatment with p38 inhibitor obviously induced autophagy. ShRNA-Gadd45b co-treatment with JNK inhibitor alleviated neuron cell apoptosis. In conclusion, our data suggested that Gadd45b inhibited autophagy and apoptosis under OGD/R. Gadd45b may be a common regulatory protein to control autophagy and apoptosis.

  10. YiQiFuMai Powder Injection Ameliorates Cerebral Ischemia by Inhibiting Endoplasmic Reticulum Stress-Mediated Neuronal Apoptosis

    PubMed Central

    Hu, Yang

    2016-01-01

    YiQiFuMai (YQFM) powder injection as a modern preparation derived from Sheng Mai San, a traditional Chinese medicine, has been widely used in the treatment of cardiovascular and cerebrovascular diseases. However, its neuroprotective effect and underlying mechanism in cerebral ischemia remain to be explored. The present study was designed to investigate the neuroprotective effect of YQFM on endoplasmic reticulum (ER) stress-mediated neuronal apoptosis in the permanent middle cerebral artery occlusion- (MCAO-) injured mice and the oxygen-glucose deprivation- (OGD-) induced pheochromocytoma (PC12) cells. The results showed that single administration of YQFM (1.342 g/kg, i.p.) could reduce the brain infarction and improve the neurological deficits and the cerebral blood flow (CBF) after MCAO for 24 h in mice. Moreover, incubation with YQFM (100, 200, and 400 μg/mL) could increase the cell viability, decrease the caspase-3 activity, and inhibit the cell apoptosis in OGD-induced PC12 cells for 12 h. In addition, YQFM treatment could significantly modulate cleaved caspase-3 and Bcl-2 expressions and inhibit the expressions of ER stress-related marker proteins and signaling pathways in vivo and in vitro. In conclusion, our findings provide the first evidence that YQFM ameliorates cerebral ischemic injury linked with modulating ER stress-related signaling pathways, which provided some new insights for its prevention and treatment of cerebral ischemia diseases. PMID:27087890

  11. Cadmium-Induced Apoptosis in Primary Rat Cerebral Cortical Neurons Culture Is Mediated by a Calcium Signaling Pathway

    PubMed Central

    Xu, Hui; Sun, Ya; Hu, Fei-fei; Bian, Jian-chun; Liu, Xue-zhong; Gu, Jian-hong; Liu, Zong-ping

    2013-01-01

    Cadmium (Cd) is an extremely toxic metal, capable of severely damaging several organs, including the brain. Studies have shown that Cd disrupts intracellular free calcium ([Ca2+]i) homeostasis, leading to apoptosis in a variety of cells including primary murine neurons. Calcium is a ubiquitous intracellular ion which acts as a signaling mediator in numerous cellular processes including cell proliferation, differentiation, and survival/death. However, little is known about the role of calcium signaling in Cd-induced apoptosis in neuronal cells. Thus we investigated the role of calcium signaling in Cd-induced apoptosis in primary rat cerebral cortical neurons. Consistent with known toxic properties of Cd, exposure of cerebral cortical neurons to Cd caused morphological changes indicative of apoptosis and cell death. It also induced elevation of [Ca2+]i and inhibition of Na+/K+-ATPase and Ca2+/Mg2+-ATPase activities. This Cd-induced elevation of [Ca2+]i was suppressed by an IP3R inhibitor, 2-APB, suggesting that ER-regulated Ca2+ is involved. In addition, we observed elevation of reactive oxygen species (ROS) levels, dysfunction of cytochrome oxidase subunits (COX-I/II/III), depletion of mitochondrial membrane potential (ΔΨm), and cleavage of caspase-9, caspase-3 and poly (ADP-ribose) polymerase (PARP) during Cd exposure. Z-VAD-fmk, a pan caspase inhibitor, partially prevented Cd-induced apoptosis and cell death. Interestingly, apoptosis, cell death and these cellular events induced by Cd were blocked by BAPTA-AM, a specific intracellular Ca2+ chelator. Furthermore, western blot analysis revealed an up-regulated expression of Bcl-2 and down-regulated expression of Bax. However, these were not blocked by BAPTA-AM. Thus Cd toxicity is in part due to its disruption of intracellular Ca2+ homeostasis, by compromising ATPases activities and ER-regulated Ca2+, and this elevation in Ca2+ triggers the activation of the Ca2+-mitochondria apoptotic signaling pathway. This

  12. Netrin-1 rescues neuron loss by attenuating secondary apoptosis in ipsilateral thalamic nucleus following focal cerebral infarction in hypertensive rats.

    PubMed

    Liao, S-J; Gong, Q; Chen, X-R; Ye, L-X; Ding, Q; Zeng, J-S; Yu, J

    2013-02-12

    Neurological deficit following cerebral infarction correlates with not only primary injury, but also secondary neuronal apoptosis in remote loci connected to the infarction. Netrin-1 is crucial for axonal guidance by interacting with its receptors, deleted in colorectal cancer (DCC) and uncoordinated gene 5H (UNC5H). DCC and UNC5H are also dependence receptors inducing cell apoptosis when unbound by netrin-1. The present study is to investigate the role of netrin-1 and its receptors in ipsilateral ventroposterior thalamic nucleus (VPN) injury secondary to stroke in hypertensive rats. Renovascular hypertensive Sprague-Dawley rats underwent middle cerebral artery occlusion (MCAO). Continuous intracerebroventricular infusion of netrin-1 (600 ng/d for 7 days) or vehicle (IgG/Fc) was given 24h after MCAO. Neurological function was evaluated by postural reflex 8 and 14 days after MCAO. Then, immunoreactivity was determined in the ipsilateral VPN for NeuN, glial fibrillary acidic protein, netrin-1 and its receptors (DCC and UNC5H2), apoptosis was detected with Terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP-biotin nick-end labeling (TUNEL) assay, and the expressions of caspase-3, netrin-1, DCC, and UNC5H2 were quantified by western blot analysis. MCAO resulted in the impaired postural reflex after 8 and 14 days, with decreased NeuN marked neurons and increased TUNEL-positive cells, as well as an up-regulation in the levels of cleaved caspase-3 and UNC5H2 protein in the ipsilateral VPN, without significant change in DCC or netrin-1 expression. By exogenous netrin-1 infusion, the number of neurons was increased in the ipsilateral VPN, and both TUNEL-positive cell number and caspase-3 protein level were reduced, while UNC5H2 expression remained unaffected, simultaneously, the impairment of postural reflex was improved. Taken together, the present study indicates that exogenous netrin-1 could rescue neuron loss by attenuating secondary apoptosis in the

  13. Effects of Nigella sativa on apoptosis and GABAA receptor density in cerebral cortical and hippocampal neurons in pentylenetetrazol induced kindling in rats.

    PubMed

    Meral, I; Esrefoglu, M; Dar, K A; Ustunova, S; Aydin, M S; Demirtas, M; Arifoglu, Y

    2016-11-01

    We investigated the effects of Nigella sativa on apoptosis and gamma-aminobutyric acid (GABAA) receptor density in cerebral cortical and hippocampal neurons in a pentylenetetrazol (PTZ)-induced kindling model in rats. The PTZ kindling model was produced by injecting PTZ in subconvulsive doses to rats on days 1, 3, 5, 8, 10, 12, 15, 17, 19, 22 and 24 of the study into animals of PTZ treated (PTZ) and PTZ + N. sativa treated (PTZ + NS) groups. Clonic and tonic seizures were induced by injecting a convulsive dose of PTZ on day 26 of the study. Rats in the PTZ + NS group were treated also with a 10 mg/kg methanolic extract of N. sativa 2 h before each PTZ injection. Rats in the control group were treated with 4 ml/kg saline. The number of neurons that expressed GABAA receptors in the hippocampus and cerebral cortex of rats in the PTZ and PTZ + NS groups increased significantly. There was no significant difference in the number of GABAA receptors between the PTZ and PTZ + NS groups. GABAA receptor density of the neurons in the cerebral cortex, but not hippocampus, was increased in PTZ group compared to controls. We observed a significant increase in the number of apoptotic neurons in the cerebral cortex of rats of both the PTZ and PTZ + NS groups compared to controls. We observed a significant decrease in the number of the apoptotic neurons in the cerebral cortex of rats in the PTZ + NS group compared to the PTZ group. N. sativa treatment ameliorated the PTZ induced neurodegeneration in the cerebral cortex as reflected by neuronal apoptosis and neuronal GABAA receptor frequency.

  14. Neurofibromin and Neuronal Apoptosis

    DTIC Science & Technology

    2006-07-01

    role of familial pheochromocytoma genes, including succinate dehydrogenase (SDH) and Nf1, in modulating neuronal apoptosis following neurotrophin...gene products, in Nf1-/- sensory and sympathetic neurons; this work will also have relevance to the biology of familial pheochromocytoma . "So what...Schlisio, S. (2005). Neuronal apoptosis linked to EglN3 prolyl hydroxylase and familial pheochromocytoma genes: Developmental culling and cancer. Cancer

  15. Effects of the TLR4 signaling pathway on apoptosis of neuronal cells in diabetes mellitus complicated with cerebral infarction in a rat model

    PubMed Central

    Li, Chao; Che, Li-He; Ji, Tie-Feng; Shi, Lei; Yu, Jin-Lu

    2017-01-01

    This study aims to explore the effects of the TLR4 signaling pathway on the apoptosis of neuronal cells in rats with diabetes mellitus complicated with cerebral infarction (DMCI). A DMCI model was established with 40 Sprague Dawley rats, which were assigned into blank, sham, DM + middle cerebral artery occlusion (MCAO) and DM + MCAO + TAK242 groups. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were measured. A TUNEL assay was applied for detecting cell apoptosis, and Western blotting was used for detecting the expression of TLR4, TNF-α, IL-1β and apoptosis-related proteins. Compared with the blank and sham groups, there was an increase in cell apoptosis, expression of Bcl-2, Bax, cleaved caspase-3, TNF-α, IL-1β and TLR4 proteins and MDA content and a decrease in SOD activity in the DM + MCAO and DM + MCAO + TAK242 groups. Compared with those in the DM + MCAO group, rats in the DM + MCAO + TAK242 group exhibited an increase in SOD activity and a decrease in cell apoptosis, expression of Bcl-2, Bax, cleaved caspase-3, TNF-α, IL-1β and TLR4 proteins and MDA content. Inhibition of the TLR4 signaling pathway reduces neuronal cell apoptosis and nerve injury to protect the brain. PMID:28272417

  16. [Effect of N(G)-nitro-L-arginine on inflammatory factor and neuronal apoptosis after focal cerebral ischemic injury in rats].

    PubMed

    Zhang, Jian-xin; Li, Lan-fang; Zhang, Hui-xin; Li, Yong-hui

    2007-11-01

    To evaluate the effect of NG-nitro-L-arginine (L-NA) on inflammatory factor and neuronal apoptosis after focal cerebral ischemic injury in rats and the possible mechanism of protective effect of L-NA against cerebral ischemic injury. Thirty male SD rats weighing 250-280 g were randomly divided into three groups (n=10): (1) Sham operated group (SH), (2) Ischemic group (IS), (3) L-NA group. In L-NA group L-NA 20 mg/kg was given intraperitoneally twice a day for 3 consecutive days. In IS group normal saline was given instead of L-NA. Focal cerebral ischemia was produced by middle cerebral artery occlusion (MCAO) for 12 h. A nylon thread with rounded tip which was inserted into left internal carotid artery cranially until resistance was felt. The distance from bifurcation of common carotid artery to the tip of the thread was about 18-19 mm. Focal cerebral ischemia was confirmed by left Horner's syndrome and right side hemiplegia. In SH group the carotid artery was exposed but no thread was inserted. The expression of TNF-alpha was determined by immunochemistry and the content of IL-1beta was measured by radio immunity. The Bcl-2 and Bax protein expression were detected by flow cytometry. The expression of TNF-alpha and the content of IL-1 beta were markedly increased after MCAO. Significantly increased DNA fragmentation indication of apoptosis was detected after MCAO. The expression of TNF-alpha and the content of IL-1 beta was significantly lower in L-NA group than in IS group. The percentage of apoptosis cells and expression of Bax protein were markedly lower in L-NA group than in IS group but still significantly higher than in SH group. The expression of Bcl-2 protein was markedly higher in L-NA group than in IS group. There was no significant difference in the expression of Bcl-2 protein between IS and SH group. L-NA could inhibit the increase in the expression of TNF-alpha and the content of IL-1beta, and protect neurons from apoptosis induced by focal cerebral

  17. Ligand-activated PPAR-γ protects against ischemic cerebral infarction and neuronal apoptosis by 14-3-3ε upregulation

    PubMed Central

    Wu, Jui-Sheng; Cheung, Wai-Mui; Tsai, Yau-Sheng; Chen, Yi-Tong; Fong, Wen-Hsuan; Tsai, Hsin-Da; Chen, Yu-Chang; Liou, Jun-Yang; Shyue, Song-Kun; Chen, Jin-Jer; Chen, Y. Eugene; Maeda, Nobuyo; Wu, Kenneth K.; Lin, Teng-Nan

    2014-01-01

    Background Thiazolidinediones (TZD) were reported to protect against ischemia-reperfusion (I/R) injury. Their protective actions are considered to be PPAR-γ (peroxisome proliferator-activated receptor γ)-dependent. However, it is unclear how PPAR-γ activation confers resistance to I/R. Methods and Results We evaluated the effects of rosiglitazone or PPAR-γ overexpression on cerebral infarction in a rat model and investigated the anti-apoptotic actions in N2-A neuroblastoma cell model. Rosiglitazone or PPAR-γ overexpression significantly reduced infarct volume. The protective effect was abrogated by PPAR-γ siRNA. In mice with knockin of a PPAR-γ domain negative mutant, infarct volume was enhanced. Proteomic analysis reveals that brain 14-3-3ε was highly upregulated in rats treated with rosiglitazone. 14-3-3ε upregulation was abrogated by PPAR-γ siRNA or antagonist. Promoter analysis and chromatin immunoprecipitation reveal that rosiglitazone induced PPAR-γ binding to specific regulatory elements on 14-3-3ε promoter and thereby increased 14-3-3ε transcription. 14-3-3ε siRNA abrogated the anti-apoptotic actions of rosiglitazone or PPAR-γ overexpression while 14-3-3ε recombinant proteins rescued brain tissues and N2-A cells from ischemia-induced damage and apoptosis. Elevated 14-3-3ε enhanced binding of phosphorylated Bad, and protected mitochondrial membrane potential. Conclusions Ligand-activated PPAR-γ confers resistance to neuronal apoptosis and cerebral infarction by driving 14-3-3ε transcription. 14-3-3ε upregulation enhances sequestration of phosphorylated Bad and thereby suppresses apoptosis. PMID:19221220

  18. L-carnosine inhibits neuronal cell apoptosis through signal transducer and activator of transcription 3 signaling pathway after acute focal cerebral ischemia.

    PubMed

    Wang, Jian-Ping; Yang, Zhi-Tang; Liu, Cong; He, Yuan-Hong; Zhao, Shan-Shan

    2013-04-24

    Considerable studies have showed that L-carnosine provides anti-oxidative and anti-apoptotic roles in the animal models of global or focal cerebral ischemia. However, the anti-apoptotic mechanisms of L-carnosine in the focal cerebral ischemia model have yet to be elucidated. To investigate the molecular mechanisms, rat models of permanent middle cerebral artery occlusion (pMCAO) and sham operation were first established and then pMCAO and sham-operated rats were treated with L-carnosine or vehicle alone. After this treatment, neurological deficits were evaluated at 12, 24 and 72 h after operation and the infarct volume was measured at 72 h after treatment. In addition, we also detected the mRNA expression of signal transducer and activator of transcription 3 (STAT3) and Pim-1 and the protein expression of phosphorylated STAT3, Pim-1, bcl-2 and cleaved caspase-3 at 12, 24 and 72 h post-pMCAO. Our results showed that the L-carnosine-treated rats had milder neurological deficits and smaller infarct volume and showed up-regulated expression in mRNA levels of STAT3 and Pim-1 than vehicle-treated rats at 72 h after treatment. Meanwhile, compared with vehicle-treated rats, the L-carnosine-treated rats exhibited higher protein expressions of pSTAT3, Pim-1 and bcl-2 but lower expression of cleaved caspase-3 protein at 72 h following operation. These results indicate that L-carnosine plays an important role in inhibiting neuronal cell apoptosis through STAT3 signaling pathway after acute cerebral ischemia.

  19. Neurofibromin and Neuronal Apoptosis

    DTIC Science & Technology

    2005-07-01

    for these differences in the response of Nfl-/- neurons. "So What" Section. The learning disabilities associated with NF I constitute a highly variable...and +/+ neurons appear to become more significant with age. Our results may have implications for two areas: 1) the pathogenesis of learning ... disabilities in children with NF I, and 2) therapeutic strategies or targets for prolonging neuron survival, or for increasing neuronal response to protective

  20. Lateral intracerebroventricular injection of Apelin-13 inhibits apoptosis after cerebral ischemia/reperfusion injury.

    PubMed

    Yan, Xiao-Ge; Cheng, Bao-Hua; Wang, Xin; Ding, Liang-Cai; Liu, Hai-Qing; Chen, Jing; Bai, Bo

    2015-05-01

    Apelin-13 inhibits neuronal apoptosis caused by hydrogen peroxide, yet apoptosis following cerebral ischemia-reperfusion injury has rarely been studied. In this study, Apelin-13 (0.1 μg/g) was injected into the lateral ventricle of middle cerebral artery occlusion model rats. TTC, TUNEL, and immunohistochemical staining showed that compared with the cerebral ischemia/reperfusion group, infarct volume and apoptotic cell number at the ischemic penumbra region were decreased in the Apelin-13 treatment group. Additionally, Apelin-13 treatment increased Bcl-2 immunoreactivity and decreased caspase-3 immunoreactivity. Our findings suggest that Apelin-13 is neuroprotective against cerebral ischemia/reperfusion injury through inhibition of neuronal apoptosis.

  1. Transient cerebral ischemia. Association of apoptosis induction with hypoperfusion.

    PubMed Central

    Vexler, Z S; Roberts, T P; Bollen, A W; Derugin, N; Arieff, A I

    1997-01-01

    Apoptosis is thought to be important in the pathogenesis of cerebral ischemia. The mechanism of apoptosis induction remains unclear but several studies suggest that it is preferentially triggered by mild/moderate microcirculatory disturbances. We examined in cats whether induction of apoptosis after 2.5 h of unilateral middle cerebral artery occlusion plus 10 h of reperfusion is influenced by the degree of cerebral microcirculatory disturbance. Quantitative monitoring over time of the disturbances of cerebral microcirculation in ischemic brain areas and evaluation of cytotoxic edema associated with perfusion deficits was achieved by using two noninvasive magnetic resonance imaging techniques: (a) high-speed echo planar imaging combined with a bolus of magnetic susceptibility contrast agent; and (b) diffusion-weighted imaging. Apoptosis-positive cells were counted in anatomic areas with different severity of ischemic injury characterized by magnetic resonance imaging, triphenyltetrazolium chloride, and hemotoxylin and eosin staining. The number of apoptosis-positive cells was significantly higher in anatomic areas with severe perfusion deficits during occlusion and detectable histologic changes 10 h after reperfusion. In contrast, in areas where perfusion was reduced but maintained during occlusion there were no detectable histological changes and significantly fewer apoptosis-positive cells. A similar number of cells that undergo apoptosis were shown in regions with transient or prolonged subtotal perfusion deficits. These results suggest that the apoptotic process is induced in the ischemic core and contributes significantly in the degeneration of neurons associated with transient ischemia. PMID:9077555

  2. [Effects of adipose-derived stem cells transplantation on the neuronal apoptosis and the expression of Bcl-2 and caspase-12 in the brain post focal cerebral ischemia in rats].

    PubMed

    Lin, Xiao-hui; Liu, Nan; Xiao, Ying-chun; Chen, Rong-hua; DU, Hou-wei; Wang, Jie-hua; Zhang, Yi-xian; Liu, De-shan

    2011-01-01

    To investigate the effects of adipose-derived stem cells (ADSCs) transplantation on neuronal apoptosis in the brain after focal cerebral ischemia in rats. 72 male adult Sprague-Dawley rats were randomly divided into 4 groups: Sham-operated group , Middle cerebral artery occlusion (MCAO) group, Vehicle group and ADSC-treated group (n=18). MCAO model was established with the modified Longa's method. One day after right MCAO, 30 μL of cell suspension containing 1×10(6); cells were injected into the lateral ventricle of ADSC-treated group and the same dose of PBS was given to the vehicle group. At 4 d, 7 d and 14 d after MCAO, the apoptosis of neuron was detected by terminal deoxynucleotidyl transferase-mediated DNA nick-end labeling (TUNEL) method and the expression of Bcl-2 and caspase-12 in ischemic region was detected by immunohistochemistry and RT-PCR. TUNEL-positive cells in ischemic region of ADSC-treated group were less than that in MCAO group and Vehicle group at 4 d, 7 d and 14 d post MCAO (P<0.05). Compared with MCAO group and Vehicle group, the expression of Bcl-2 significantly up-regulated while caspase-12 expression significantly decreased in ADSC-treated group at any time point post MCAO (P<0.05). The transplantation of ADSCs can reduce neuronal apoptosis of rats with cerebral ischemic injury partly by promoting the expression of Bcl-2 which participates in apoptotic signals after mitochondrial damage and inhibiting the expression of caspase-12 which mediates endoplasmic reticulum (ER) stress-induced apoptosis.

  3. Semaphorins as mediators of neuronal apoptosis.

    PubMed

    Shirvan, A; Ziv, I; Fleminger, G; Shina, R; He, Z; Brudo, I; Melamed, E; Barzilai, A

    1999-09-01

    Shrinkage and collapse of the neuritic network are often observed during the process of neuronal apoptosis. However, the molecular and biochemical basis for the axonal damage associated with neuronal cell death is still unclear. We present evidence for the involvement of axon guidance molecules with repulsive cues in neuronal cell death. Using the differential display approach, an up-regulation of collapsin response mediator protein was detected in sympathetic neurons undergoing dopamine-induced apoptosis. A synchronized induction of mRNA of the secreted collapsin-1 and the intracellular collapsin response mediator protein that preceded commitment of neurons to apoptosis was detected. Antibodies directed against a conserved collapsin-derived peptide provided marked and prolonged protection of several neuronal cell types from dopamine-induced apoptosis. Moreover, neuronal apoptosis was inhibited by antibodies against neuropilin-1, a putative component of the semaphorin III/collapsin-1 receptor. Induction of neuronal apoptosis was also caused by exposure of neurons to semaphorin III-alkaline phosphatase secreted from 293EBNA cells. Anti-collapsin-1 antibodies were effective in blocking the semaphorin III-induced death process. We therefore suggest that, before their death, apoptosis-destined neurons may produce and secrete destructive axon guidance molecules that can affect their neighboring cells and thus transfer a "death signal" across specific and susceptible neuronal populations.

  4. Ecdysterone protects gerbil brain from temporal global cerebral ischemia/reperfusion injury via preventing neuron apoptosis and deactivating astrocytes and microglia cells.

    PubMed

    Wang, Wei; Wang, Tao; Feng, Wan-Yu; Wang, Zhan-You; Cheng, Mao-Sheng; Wang, Yun-Jie

    2014-01-01

    Ecdysterone (EDS), a common derivative of ecdysteroid, has shown its effects on alleviating cognitive impairment and improving the cognition and memory. However, the mechanisms remain unknown. Using temporal global forebrain ischemia and reperfusion-induced brain injury as a model system, we investigated the roles of EDS in improving cognitive impairment in gerbil. Our results demonstrated that intraperitoneal injection of EDS obviously increased the number of surviving neuron cells by Nissl and neuronal nuclei (NeuN) staining. Indeed, the protecting effects of EDS are because of its ability to prevent the apoptosis of neuron cells as evidenced by TUNEL staining and caspase-3 deactivation in the brain of temporal global forebrain ischemia/reperfusion-treated gerbil. Moreover, EDS administration suppressed the ischemia stimulated activity of astrocytes and microglia cells by inhibiting the production of tumor necrosis alpha (TNF-α) in the brain of gerbil. More importantly, these actions of neurons and astrocytes/microglia cells in response to EDS treatment played pivotal roles in ameliorating the cognitive impairment in the ischemia/reperfusion-injured gerbil. In view of these observations, we not only decipher the mechanisms of EDS in reducing the syndrome of ischemia, but also provide novel perspectives to combat ischemic stroke.

  5. Apoptosis and in vitro Alzheimer disease neuronal models

    PubMed Central

    Calissano, P; Matrone, C

    2009-01-01

    Alzheimer disease (AD) is a human neurodegenerative disease characterized by co-existence of extracellular senile plaques (SP) and neurofibrillary tangles (NFT) associated with an extensive neuronal loss, primarily in the cerebral cortex and hippocampus. Several studies suggest that caspase(s)-mediated neuronal death occurs in cellular and animal AD models as well as in human brains of affected patients, although an etiologic role of apoptosis in such neurodegenerative disorder is still debated. This review summarizes the experimental evidences corroborating the possible involvement of apoptosis in AD pathogenesis and discusses the usefulness of ad hoc devised in vitro approaches to study how caspase(s), amyloidogenic processing and tau metabolism might reciprocally interact leading to neuronal death. PMID:19513272

  6. Lateral intracerebroventricular injection of Apelin-13 inhibits apoptosis after cerebral ischemia/reperfusion injury

    PubMed Central

    Yan, Xiao-ge; Cheng, Bao-hua; Wang, Xin; Ding, Liang-cai; Liu, Hai-qing; Chen, Jing; Bai, Bo

    2015-01-01

    Apelin-13 inhibits neuronal apoptosis caused by hydrogen peroxide, yet apoptosis following cerebral ischemia-reperfusion injury has rarely been studied. In this study, Apelin-13 (0.1 μg/g) was injected into the lateral ventricle of middle cerebral artery occlusion model rats. TTC, TUNEL, and immunohistochemical staining showed that compared with the cerebral ischemia/reperfusion group, infarct volume and apoptotic cell number at the ischemic penumbra region were decreased in the Apelin-13 treatment group. Additionally, Apelin-13 treatment increased Bcl-2 immunoreactivity and decreased caspase-3 immunoreactivity. Our findings suggest that Apelin-13 is neuroprotective against cerebral ischemia/reperfusion injury through inhibition of neuronal apoptosis. PMID:26109951

  7. Generation of complement component C5a by ischemic neurons promotes neuronal apoptosis.

    PubMed

    Pavlovski, Dale; Thundyil, John; Monk, Peter N; Wetsel, Rick A; Taylor, Stephen M; Woodruff, Trent M

    2012-09-01

    C5a receptors are found in the central nervous system (CNS), on both neurons and glia. However, the origin of the C5a, which activates these receptors, is unclear. In the present study, we show that primary cultured mouse cortical neurons constitutively express C5, the precursor of C5a, and express the classical receptor for C5a, CD88. With cell ischemia caused by 12 h glucose deprivation, or oxygen-glucose deprivation (OGD), neurons demonstrated increased apoptosis, up-regulation of CD88, and increased levels of C5a in the media. Exogenous murine C5a (100 nM) added to the neuronal cultures resulted in apoptosis, without affecting cell necrosis. Pretreatment of the cells with the specific CD88 receptor antagonist PMX53 (100 nM) significantly blocked ischemia-induced apoptosis (∼50%), and neurons from CD88(-/-) mice were similarly protected. In a murine model of stroke, using middle cerebral artery occlusion (MCAO), we found that C5a levels in the brain increased; this also occurred in cerebral slice cultures exposed to OGD. CD88(-/-) mice subjected to MCAO had significantly reduced infarct volumes and improved neurological scores. Taken together, our results demonstrate that neurons in the CNS have the capability to generate C5a following ischemic stress, and this has the potential to activate their C5a receptors, with deleterious consequences.

  8. Neuronal apoptosis in the neonates born to preeclamptic mothers.

    PubMed

    Cosar, Hese; Ozer, Erdener; Topel, Hande; Kahramaner, Zelal; Turkoglu, Ebru; Erdemir, Aydin; Sutcuoglu, Sumer; Bagriyanik, Alper; Ozer, Esra Arun

    2013-07-01

    Preeclampsia may result in uteroplacental insufficiency and chronic intrauterine fetal distress. The aim of this study is to address this issue investigating neuronal apoptosis in an experimental model of preeclampsia and to evaluate the neurological outcome of the perinatal asphyxia in the neonates born to preeclamptic mother. Two out of four pregnant Sprague-Dawley rats (preeclamptic group) were given water containing 1.8% NaCl on gestation day 15 and 22 in order to establish the model of preeclampsia whereas other two (non-preeclamptic group) received normal diet. A model of perinatal asphyxia was established on the postnatal 7th day to one preeclamptic and one non-preeclamptic dam. Overall 23 pups born to overall four dams were decapitated to assess neuronal apoptosis by the TUNEL assay. The number of apoptotic neuronal cells was significantly higher in the preeclampsia groups in comparison with the control group (p = 0.006 and p = 0.006, respectively). It was also significantly higher in the asphyctic/non-preeclamptic group than the count in the control group (p = 0.01). There was also significant difference between both asphyctic groups (p = 0.003). We conclude that preeclampsia causes small babies for the gestational age and cerebral hypoplasia. Both preeclampsia and perinatal asphyxia can cause increased neuronal apoptosis in the neonatal brains. However, the prognosis for neurological outcome is much worse when the perinatal asphyxia occurs in newborns born to preeclamptic mothers.

  9. The Age of Human Cerebral Cortex Neurons

    SciTech Connect

    Bhardwaj, R D; Curtis, M A; Spalding, K L; Buchholz, B A; Fink, D; Bjork-Eriksson, T; Nordborg, C; Gage, F H; Druid, H; Eriksson, P S; Frisen, J

    2006-04-06

    The traditional static view of the adult mammalian brain has been challenged by the realization of continuous generation of neurons from stem cells. Based mainly on studies in experimental animals, adult neurogenesis may contribute to recovery after brain insults and decreased neurogenesis has been implicated in the pathogenesis of neurological and psychiatric diseases in man. The extent of neurogenesis in the adult human brain has, however, been difficult to establish. We have taken advantage of the integration of {sup 14}C, generated by nuclear bomb tests during the Cold War, in DNA to establish the age of neurons in the major areas of the human cerebral cortex. Together with the analysis of the cortex from patients who received BrdU, which integrates in the DNA of dividing cells, our results demonstrate that whereas non-neuronal cells turn over, neurons in the human cerebral cortex are not generated postnatally at detectable levels, but are as old as the individual.

  10. Excitotoxins in neuronal apoptosis and necrosis.

    PubMed

    Nicotera, P; Lipton, S A

    1999-06-01

    Neuronal loss is common to many neurodegenerative diseases. Although necrosis is a common histopathologic feature observed in neuropathologic conditions, evidence is increasing that apoptosis can significantly contribute to neuronal demise. The prevalence of either type of cell death, apoptosis or necrosis, and the relevance for the progression of disease is still unclear. The debate on the occurrence and prevalence of one or the other type of death in pathologic conditions such as stroke or neurotoxic injury may in part be resolved by the proposal that different types of cell death within a tissue reflect either partial or complete execution of a common death program. Apoptosis is an active process of cell destruction, characterized morphologically by cell shrinkage, chromatin aggregation with extensive genomic fragmentation, and nuclear pyknosis. In contrast, necrosis is characterized by cell swelling, linked to rapid energy loss, and generalized disruption of ionic and internal homeostasis. This swiftly leads to membrane lysis, release of intracellular constituents that evoke a local inflammatory reaction, edema, and injury to the surrounding tissue. During the past few years, our laboratories have studied the signals and mechanisms responsible for induction or prevention of apoptosis/necrosis in neuronal injury and this is the subject of this review.

  11. Intermittent fasting is neuroprotective in focal cerebral ischemia by minimizing autophagic flux disturbance and inhibiting apoptosis.

    PubMed

    Jeong, Ji Heun; Yu, Kwang Sik; Bak, Dong Ho; Lee, Je Hun; Lee, Nam Seob; Jeong, Young Gil; Kim, Dong Kwan; Kim, Jwa-Jin; Han, Seung-Yun

    2016-11-01

    Previous studies have demonstrated that autophagy induced by caloric restriction (CR) is neuroprotective against cerebral ischemia. However, it has not been determined whether intermittent fasting (IF), a variation of CR, can exert autophagy-related neuroprotection against cerebral ischemia. Therefore, the neuroprotective effect of IF was evaluated over the course of two weeks in a rat model of focal cerebral ischemia, which was induced by middle cerebral artery occlusion and reperfusion (MCAO/R). Specifically, the role of autophagy modulation as a potential underlying mechanism for this phenomenon was investigated. It was demonstrated that IF reduced infarct volume and brain edema, improved neurobehavioral deficits, and rescued neuronal loss after MCAO/R. Furthermore, neuronal apoptosis was decreased by IF in the rat cortex. An increase in the number of autophagosomes (APs) was demonstrated in the cortices of IF-treated rats, using immunofluorescence staining and transmission electron microscopy. Using immunoblots, an IF-induced increase was detected in microtubule-associated protein 1 light chain 3 (LC3)-II, Rab7, and cathepsin D protein levels, which corroborated previous morphological studies. Notably, IF reduced the accumulation of APs and p62, demonstrating that IF attenuated the MCAO/R-induced disturbance of autophagic flux in neurons. The findings of the present study suggest that IF-induced neuroprotection in focal cerebral ischemia is due, at least in part, to the minimization of autophagic flux disturbance and inhibition of apoptosis.

  12. Intermittent fasting is neuroprotective in focal cerebral ischemia by minimizing autophagic flux disturbance and inhibiting apoptosis

    PubMed Central

    Jeong, Ji Heun; Yu, Kwang Sik; Bak, Dong Ho; Lee, Je Hun; Lee, Nam Seob; Jeong, Young Gil; Kim, Dong Kwan; Kim, Jwa-Jin; Han, Seung-Yun

    2016-01-01

    Previous studies have demonstrated that autophagy induced by caloric restriction (CR) is neuroprotective against cerebral ischemia. However, it has not been determined whether intermittent fasting (IF), a variation of CR, can exert autophagy-related neuroprotection against cerebral ischemia. Therefore, the neuroprotective effect of IF was evaluated over the course of two weeks in a rat model of focal cerebral ischemia, which was induced by middle cerebral artery occlusion and reperfusion (MCAO/R). Specifically, the role of autophagy modulation as a potential underlying mechanism for this phenomenon was investigated. It was demonstrated that IF reduced infarct volume and brain edema, improved neurobehavioral deficits, and rescued neuronal loss after MCAO/R. Furthermore, neuronal apoptosis was decreased by IF in the rat cortex. An increase in the number of autophagosomes (APs) was demonstrated in the cortices of IF-treated rats, using immunofluorescence staining and transmission electron microscopy. Using immunoblots, an IF-induced increase was detected in microtubule-associated protein 1 light chain 3 (LC3)-II, Rab7, and cathepsin D protein levels, which corroborated previous morphological studies. Notably, IF reduced the accumulation of APs and p62, demonstrating that IF attenuated the MCAO/R-induced disturbance of autophagic flux in neurons. The findings of the present study suggest that IF-induced neuroprotection in focal cerebral ischemia is due, at least in part, to the minimization of autophagic flux disturbance and inhibition of apoptosis. PMID:27882110

  13. Pharmacologic preconditioning with berberine attenuating ischemia-induced apoptosis and promoting autophagy in neuron

    PubMed Central

    Zhang, Qichun; Bian, Huimin; Guo, Liwei; Zhu, Huaxu

    2016-01-01

    Pharmacologic preconditioning is an intriguing and emerging approach adopted to prevent injury of ischemia/reperfusion. Neuroprotection is the cardinal effect of these pleiotropic actions of berberine. Here we investigated that whether berberine could acts as a preconditioning stimuli contributing to attenuate hypoxia-induced neurons death as well. Male Sprague-Dawley rats of middle cerebral artery occlusion (MCAO) and rat primary cortical neurons undergoing oxygen and glucose deprivation (OGD) were preconditioned with berberine (40 mg/kg, for 24 h in vivo, and 10-6 mol/L, for 2 h in vitro, respectively). The neurological deficits and cerebral water contents of MCAO rats were evaluated. The autophagy and apoptosis were further determined in primary neurons in vitro. Berberine preconditioning (BP) was then shown to ameliorate the neurological deficits, decrease cerebral water content and promote neurogenesis of MCAO rats. Decreased LDH release from OGD-treated neurons was observed via BP, which was blocked by LY294002 (20 µmol/L), GSK690693 (10 µmol/L), or YC-1 (25 µmol/L). Furthermore, BP stimulated autophagy and inhibited apoptosis via modulated the autophagy-associated proteins LC 3, Beclin-1 and p62, and apoptosis-modulating proteins caspase 3, caspase 8, caspase 9, PARP and BCL-2/Bax. In conclusion, berberine acts as a stimulus of preconditioning that exhibits neuroprotection via promoting autophagy and decreasing anoxia-induced apoptosis. PMID:27158406

  14. Lithium protects ethanol-induced neuronal apoptosis

    SciTech Connect

    Zhong Jin . E-mail: jizhong@iupui.edu; Yang Xianlin; Yao Weiguo; Lee Weihua

    2006-12-01

    Lithium is widely used for the treatment of bipolar disorder. Recent studies have demonstrated its neuroprotective effect. Ethanol is a potent neurotoxin that is particularly harmful to the developing nervous system. In this study, we evaluated lithium's neuroprotection against ethanol-induced apoptosis. Transient exposure of infant mice to ethanol caused apoptotic cell death in brain, which was prevented significantly by administering a low dose of lithium 15 min later. In cultured cerebellar granule neurons, ethanol-induced apoptosis and activation of caspase-3/9, both of which were prevented by lithium. However, lithium's protection is not mediated by its commonly known inhibition of glycogen synthase3{beta}, because neither ethanol nor lithium has significant effects on the phosphorylation of Akt (ser473) or GSK3{beta} (ser9). In addition, the selective GSK-3{beta} inhibitor SB-415286 was unable to prevent ethanol-induced apoptosis. These data suggest lithium may be used as a potential preventive measure for ethanol-induced neurological deficits.

  15. Amyloid β-42 induces neuronal apoptosis by targeting mitochondria.

    PubMed

    Han, Xiao-Jian; Hu, Yang-Yang; Yang, Zhang-Jian; Jiang, Li-Ping; Shi, Sheng-Lan; Li, Ye-Ru; Guo, Miao-Yu; Wu, Hong-Li; Wan, Yu-Ying

    2017-10-01

    Alzheimer's disease (AD), with a typical pathological hallmark of amyloid‑beta (Aβ)‑containing plaques and neurofibrillary tangles, is one of the most common types of chronic neurodegenerative diseases. Aβ oligomers serve a crucial role in the pathogenesis of AD, and lead to neuronal loss. However, the precise mechanism of Aβ oligomers in AD remains to be elucidated. The present study demonstrated that 10 µM Aβ‑42 activated the caspase signaling pathway, and induced significant apoptosis in primary cultured mouse cerebral cortical neurons. The results of reverse transcription‑quantitative polymerase chain reaction and western blotting demonstrated that Aβ‑42 (10 µM) also significantly upregulated the transcription and expression of the mitochondrial fission protein dynamin‑related protein 1 (Drp1), and downregulated the transcription and expression of mitochondrial fusion proteins, including mitofusin 1/2 (Mfn1/2) and mitochondrial dynamin like GTPase (OPA‑1). Neurons were transfected with pDsRed2‑Mito for mitochondrial imaging, which revealed that 10 µM Aβ‑42 induced mitochondrial fission in cortical neurons. In addition, 2',7'‑dichlorodihydrofluorescein diacetate and tetramethylrhodamine ethyl ester staining indicated that Aβ‑42 increased the reactive oxygen species (ROS) level and reduced mitochondrial membrane potential in neurons. Inhibition of Drp1 activity by Mdivi‑1 efficiently prevented Aβ‑42‑induced ROS production and disruption of mitochondrial membrane potential. Loss of mitochondrial membrane potential may activate PTEN‑induced putative kinase 1 (Pink1), the prominent sensor for mitochondrial damage, and trigger the process of mitophagy to remove the damaged mitochondria. In the present study, western blotting revealed that the levels of autophagy marker microtubule‑associated proteins 1A/1B light chain 3B (LC3B) and Pink1 were upregulated after Aβ‑42 stimulation. In conclusion, these data indicated that

  16. Role of PUMA in methamphetamine-induced neuronal apoptosis.

    PubMed

    Chen, Chuanxiang; Qincao, Litao; Xu, Jingtao; Du, Sihao; Huang, Enping; Liu, Chao; Lin, Zhoumeng; Xie, Wei-Bing; Wang, Huijun

    2016-01-05

    Exposure to methamphetamine (METH), a widely used illicit drug, has been shown to cause neuron apoptosis. p53 upregulated modulator of apoptosis (PUMA) is a key mediator in neuronal apoptosis. This study aimed to examine the effects of PUMA in METH-induced neuronal apoptosis. We determined PUMA protein expression in PC12 cells and SH-SY5Y cells after METH exposure using western blot. We also observed the effect of METH on neuronal apoptosis after silencing PUMA expression with siRNA using TUNEL staining and flow cytometry. Additionally, to investigate possible mechanisms of METH-induced PUMA-mediated neuronal apoptosis, we measured the protein expression of apoptotic markers, including cleaved caspase-3, cleaved PARP, Bax, B-cell leukemia/lymphoma-2 (Bcl-2) and cytochrome c (cyto c), after METH treatment with or without PUMA knockdown. Results showed that METH exposure induced cell apoptosis, increased PUMA protein levels, activated caspase-3 and PARP, elevated Bax and reduced Bcl-2 expression, as well as increased the release of cyto c from mitochondria to the cytoplasm in both PC12 and SH-SY5Y cells. All these effects were attenuated or reversed after silencing PUMA. A schematic depicting the role of PUMA in METH-induced mitochondrial apoptotic pathway was proposed. Our results suggest that PUMA plays an important role in METH-triggered apoptosis and it may be a potential target for ameliorating neuronal injury and apoptosis caused by METH.

  17. Antioxidants Prevent Ethanol-Associated Apoptosis in Fetal Rhombencephalic Neurons

    PubMed Central

    Antonio, Angeline M.; Druse, Mary J.

    2008-01-01

    It is well known that ethanol damages the developing nervous system by augmenting apoptosis. Previously, this laboratory reported that ethanol augments apoptosis in fetal rhombencephalic neurons, and that the increased apoptosis is associated with reduced activity of the phosphatidylinositol 3’kinase pathway and downstream expression of pro-survival genes. Other laboratories have shown that another mechanism by which ethanol induces apoptosis in developing neurons is through the generation of reactive oxygen species (ROS) and the associated oxidative stress. The present study used an in vitro model to investigate the potential neuroprotective effects of several antioxidants against ethanol-associated apoptosis in fetal rhombencephalic neurons. The investigated antioxidants included three phenolics: (-)-epigallocatechin-3-gallate (EGCG), a flavanoid polyphenol found in green tea; curcumin, found in tumeric; and resveratrol (3,5,4’-trihydroxystilbene), a component of red wine. Additional antioxidants, including melatonin, a naturally occurring indole, and α-lipoic acid, a naturally occurring dithiol, were also investigated. These studies demonstrated that a 24-hour treatment of fetal rhombencephalic neurons with 75 mM ethanol caused a 3-fold increase in the percentage of apoptotic neurons. However, co-treatment of these cultures with any of the five different antioxidants prevented ethanol-associated apoptosis. Antioxidant treatment did not alter the extent of apoptosis in control neurons, i.e., those cultured in the absence of ethanol. These studies showed that several classes of antioxidants can exert neuroprotection against ethanol-associated apoptosis in fetal rhombencephalic neurons. PMID:18329634

  18. O-GlcNAcylation regulates ischemia-induced neuronal apoptosis through AKT signaling

    PubMed Central

    Shi, Jianhua; Gu, Jin-hua; Dai, Chun-ling; Gu, Jianlan; Jin, Xiaoxia; Sun, Jianming; Iqbal, Khalid; Liu, Fei; Gong, Cheng-Xin

    2015-01-01

    Apoptosis plays an important role in neural development and neurological disorders. In this study, we found that O-GlcNAcylation, a unique protein posttranslational modification with O-linked β-N-acetylglucosamine (GlcNAc), promoted apoptosis through attenuating phosphorylation/activation of AKT and Bad. By using co-immunoprecipitation and mutagenesis techniques, we identified O-GlcNAc modification at both Thr308 and Ser473 of AKT. O-GlcNAcylation-induced apoptosis was attenuated by over-expression of AKT. We also found a dynamic elevation of protein O-GlcNAcylation during the first four hours of cerebral ischemia, followed by continuous decline after middle cerebral artery occlusion (MCAO) in the mouse brain. The elevation of O-GlcNAcylation coincided with activation of cell apoptosis. Finally, we found a negative correlation between AKT phosphorylation and O-GlcNAcylation in ischemic brain tissue. These results indicate that cerebral ischemia induces a rapid increase of O-GlcNAcylation that promotes apoptosis through down-regulation of AKT activity. These findings provide a novel mechanism through which O-GlcNAcylation regulates ischemia-induced neuronal apoptosis through AKT signaling. PMID:26412745

  19. Inhibition of cerebral ischemia/reperfusion injury-induced apoptosis: nicotiflorin and JAK2/STAT3 pathway

    PubMed Central

    Hu, Guang-qiang; Du, Xi; Li, Yong-jie; Gao, Xiao-qing; Chen, Bi-qiong; Yu, Lu

    2017-01-01

    Nicotiflorin is a flavonoid extracted from Carthamus tinctorius. Previous studies have shown its cerebral protective effect, but the mechanism is undefined. In this study, we aimed to determine whether nicotiflorin protects against cerebral ischemia/reperfusion injury-induced apoptosis through the JAK2/STAT3 pathway. The cerebral ischemia/reperfusion injury model was established by middle cerebral artery occlusion/reperfusion. Nicotiflorin (10 mg/kg) was administered by tail vein injection. Cell apoptosis in the ischemic cerebral cortex was examined by hematoxylin-eosin staining and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Bcl-2 and Bax expression levels in ischemic cerebral cortex were examined by immunohistochemial staining. Additionally, p-JAK2, p-STAT3, Bcl-2, Bax, and caspase-3 levels in ischemic cerebral cortex were examined by western blot assay. Nicotiflorin altered the shape and structure of injured neurons, decreased the number of apoptotic cells, down-regulates expression of p-JAK2, p-STAT3, caspase-3, and Bax, decreased Bax immunoredactivity, and increased Bcl-2 protein expression and immunoreactivity. These results suggest that nicotiflorin protects against cerebral ischemia/reperfusion injury-induced apoptosis via the JAK2/STAT3 pathway. PMID:28250754

  20. L-3-n-Butylphthalide Activates Akt/mTOR Signaling, Inhibits Neuronal Apoptosis and Autophagy and Improves Cognitive Impairment in Mice with Repeated Cerebral Ischemia-Reperfusion Injury.

    PubMed

    Xu, Jing; Huai, Yaping; Meng, Nan; Dong, Yanhong; Liu, Zhijuan; Qi, Qianqian; Hu, Ming; Fan, Mingyue; Jin, Wei; Lv, Peiyuan

    2017-06-15

    L-3-n-Butylphthalide (L-NBP) exerts neuroprotective effects in animal models of cerebral ischemia, but its potential benefits in repeated cerebral ischemia-reperfusion (RCIR) injury remain unknown. We investigated the effect of L-NBP on cognitive impairment induced by RCIR in mice. Male C57Bl/6 mice received sham surgery or bilateral common carotid artery occlusion (3 times, 20 min each) and were orally administered preoperative L-NBP (30 mg/kg/day, 7 days), postoperative L-NBP (30 or 60 mg/kg/day, 28 days) or postoperative vehicle (28 days). Learning and memory were assessed by the Morris water maze task and step-down passive avoidance test. Nissl staining was used to identify pathologic changes in the hippocampal CA1 region. The expressions of proteins associated with signaling, apoptosis and autophagy were assessed by quantitative PCR and western blot. RCIR induced deficits in learning and memory that were alleviated by preoperative or postoperative L-NBP administration. Pathologic lesions in the hippocampal CA1 region induced by RCIR were less severe in mice treated with L-NBP. Preoperative or postoperative L-NBP administration in mice receiving RCIR promoted hippocampal expression of phospho-Akt and phospho-mTOR (suggesting activation of Akt/mTOR signaling), increased the Bcl-2/Bax ratio (indicating suppression of apoptosis) and reduced the LC3-II/LC3-I ratio (implying inhibition of autophagy). Preoperative or postoperative L-NBP administration also depressed hippocampal levels of beclin-1 mRNA (indicating suppression of autophagy). These findings suggest that the effect of L-NBP to alleviate learning and memory deficits in mice following RCIR may involve activation of Akt/mTOR signaling and regulation of the expressions of proteins related to apoptosis and autophagy.

  1. Multimodal MRI Imaging of Apoptosis-Triggered Microstructural Alterations in the Postnatal Cerebral Cortex.

    PubMed

    Petrenko, Volodymyr; van de Looij, Yohan; Mihhailova, Jevgenia; Salmon, Patrick; Hüppi, Petra S; Sizonenko, Stéphane V; Kiss, Jozsef Z

    2017-02-03

    Prematurely born children often develop neurodevelopmental delay that has been correlated with reduced growth and microstructural alterations in the cerebral cortex. Much research has focused on apoptotic neuronal cell death as a key neuropathological features following preterm brain injuries. How scattered apoptotic death of neurons may contribute to microstructural alterations remains unknown. The present study investigated in a rat model the effects of targeted neuronal apoptosis on cortical microstructure using in vivo MRI imaging combined with neuronal reconstruction and histological analysis. We describe that mild, targeted death of layer IV neurons in the developing rat cortex induces MRI-defined metabolic and microstructural alterations including increased cortical fractional anisotropy. Delayed architectural modifications in cortical gray matter and myelin abnormalities in the subcortical white matter such as hypomyelination and microglia activation follow the acute phase of neuronal death and axonal degeneration. These results establish the link between mild cortical apoptosis and MRI-defined microstructure changes that are reminiscent to those previously observed in preterm babies. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Human group IIA secretory phospholipase A2 induces neuronal cell death via apoptosis.

    PubMed

    Yagami, Tatsurou; Ueda, Keiichi; Asakura, Kenji; Hata, Satoshi; Kuroda, Takayuki; Sakaeda, Toshiyuki; Takasu, Nobuo; Tanaka, Kazushige; Gemba, Takefumi; Hori, Yozo

    2002-01-01

    Expression of group IIA secretory phospholipase A2 (sPLA2-IIA) is documented in the cerebral cortex (CTX) after ischemia, suggesting that sPLA2-IIA is associated with neurodegeneration. However, how sPLA2-IIA is involved in the neurodegeneration remains obscure. To clarify the pathologic role of sPLA2-IIA, we examined its neurotoxicity in rats that had the middle cerebral artery occluded and in primary cultures of cortical neurons. After occlusion, sPLA2 activity was increased in the CTX. An sPLA2 inhibitor, indoxam, significantly ameliorated not only the elevated activity of the sPLA2 but also the neurodegeneration in the CTX. The neuroprotective effect of indoxam was observed even when it was administered after occlusion. In primary cultures, sPLA2-IIA caused marked neuronal cell death. Morphologic and ultrastructural characteristics of neuronal cell death by sPLA2-IIA were apoptotic, as evidenced by condensed chromatin and fragmented DNA. Before apoptosis, sPLA2-IIA liberated arachidonic acid (AA) and generated prostaglandin D2 (PGD2), an AA metabolite, from neurons. Indoxam significantly suppressed not only AA release, but also PGD2 generation. Indoxam prevented neurons from sPLA2-IIA-induced neuronal cell death. The neuroprotective effect of indoxam was observed even when it was administered after sPLA2-IIA treatment. Furthermore, a cyclooxygenase-2 inhibitor significantly prevented neurons from sPLA2-IIA-induced PGD2 generation and neuronal cell death. In conclusion, sPLA2-IIA induces neuronal cell death via apoptosis, which might be associated with AA metabolites, especially PGD2. Furthermore, sPLA2 contributes to neurodegeneration in the ischemic brain, highlighting the therapeutic potential of sPLA2-IIA inhibitors for stroke.

  3. Mature neurons dynamically restrict apoptosis via redundant premitochondrial brakes.

    PubMed

    Annis, Ryan P; Swahari, Vijay; Nakamura, Ayumi; Xie, Alison X; Hammond, Scott M; Deshmukh, Mohanish

    2016-12-01

    Apoptotic cell death is critical for the early development of the nervous system, but once the nervous system is established, the apoptotic pathway becomes highly restricted in mature neurons. However, the mechanisms underlying this increased resistance to apoptosis in these mature neurons are not completely understood. We have previously found that members of the miR-29 family of microRNAs (miRNAs) are induced with neuronal maturation and that overexpression of miR-29 was sufficient to restrict apoptosis in neurons. To determine whether endogenous miR-29 alone was responsible for the inhibition of cytochrome c release in mature neurons, we examined the status of the apoptotic pathway in sympathetic neurons deficient for all three miR-29 family members. Unexpectedly, we found that the apoptotic pathway remained largely restricted in miR-29-deficient mature neurons. We therefore probed for additional mechanisms by which mature neurons resist apoptosis. We identify miR-24 as another miRNA that is upregulated in the maturing cerebellum and sympathetic neurons that can act redundantly with miR-29 by targeting a similar repertoire of prodeath BH3-only genes. Overall, our results reveal that mature neurons engage multiple redundant brakes to restrict the apoptotic pathway and ensure their long-term survival. © 2016 Federation of European Biochemical Societies.

  4. Neuronal remodeling and apoptosis require VCP-dependent degradation of the apoptosis inhibitor DIAP1

    PubMed Central

    Rumpf, Sebastian; Lee, Sung Bae; Jan, Lily Yeh; Jan, Yuh Nung

    2011-01-01

    The regulated degeneration of axons or dendrites (pruning) and neuronal apoptosis are widely used during development to determine the specificity of neuronal connections. Pruning and apoptosis often share similar mechanisms; for example, developmental dendrite pruning of Drosophila class IV dendritic arborization (da) neurons is induced by local caspase activation triggered by ubiquitin-mediated degradation of the caspase inhibitor DIAP1. Here, we examined the function of Valosin-containing protein (VCP), a ubiquitin-selective AAA chaperone involved in endoplasmic reticulum-associated degradation, autophagy and neurodegenerative disease, in Drosophila da neurons. Strong VCP inhibition is cell lethal, but milder inhibition interferes with dendrite pruning and developmental apoptosis. These defects are associated with impaired caspase activation and high DIAP1 levels. In cultured cells, VCP binds to DIAP1 in a ubiquitin- and BIR domain-dependent manner and facilitates its degradation. Our results establish a new link between ubiquitin, dendrite pruning and the apoptosis machinery. PMID:21343367

  5. RTN1-C mediates cerebral ischemia/reperfusion injury via ER stress and mitochondria-associated apoptosis pathways.

    PubMed

    Gong, Lingli; Tang, Yuewen; An, Ran; Lin, Muya; Chen, Lijian; Du, Jian

    2017-10-05

    The reticulon family has been found to induce apoptosis, inhibit axon regeneration and regulate protein trafficking. However, little is known about the mechanisms of how reticulon proteins are involved in neuronal death-promoting processes during ischemia. Here, we report that the expression of Reticulon Protein 1-C (RTN1-C) was associated with the progression of cerebral ischemia/reperfusion (I/R) injury. Using a combination of rat middle cerebral artery occlusion (MCAO) stroke and oxygen-glucose deprivation followed by reoxygenation (OGD/R) models, we determined that the expression of RTN1-C was significantly increased during cerebral ischemic/reperfusion. RTN1-C overexpression induced apoptosis and increased the cell vulnerability to ischemic injury, whereas RTN1-C knockdown reversed ischemia-induced apoptosis and attenuated the vulnerability of OGD/R-treated neural cells. Mechanistically, we demonstrated that RTN1-C mediated OGD/R-induced apoptosis through ER stress and mitochondria-associated pathways. RTN1-C interacted with Bcl-xL and increased its localization in the ER, thus reducing the anti-apoptotic activity of Bcl-xL. Most importantly, knockdown of Rtn1-c expression in vivo attenuated apoptosis in MCAO rats and reduced the extent of I/R-induced brain injury, as assessed by infarct volume and neurological score. Collectively, these data support for the first time that RTN1-C may represent a novel candidate for therapies against cerebral ischemia/reperfusion injury.

  6. Cerebral ischemia produces laddered DNA fragments distinct from cardiac ischemia and archetypal apoptosis.

    PubMed

    MacManus, J P; Fliss, H; Preston, E; Rasquinha, I; Tuor, U

    1999-05-01

    The electrophoretic pattern of laddered DNA fragments which has been observed after cerebral ischemia is considered to indicate that neurons are dying by apoptosis. Herein the authors directly demonstrate using ligation-mediated polymerase chain reaction methods that 99% of the DNA fragments produced after either global or focal ischemia in adult rats, or produced after hypoxia-ischemia in neonatal rats, have staggered ends with a 3' recess of approximately 8 to 10 nucleotides. This is in contrast to archetypal apoptosis in which the DNA fragments are blunt ended as seen during developmental programmed cell death in dying cortical neurons, neuroblastoma, or thymic lymphocytes. It is not simply ischemia that results in staggered ends in DNA fragments because ischemic myocardium is similar to archetypal apoptosis with a vast majority of blunt-ended fragments. It is concluded that the endonucleases that produce this staggered fragmentation of the DNA backbone in ischemic brain must be different than those of classic or type I apoptosis.

  7. Neuronal polarization in the developing cerebral cortex

    PubMed Central

    Sakakibara, Akira; Hatanaka, Yumiko

    2015-01-01

    Cortical neurons consist of excitatory projection neurons and inhibitory GABAergic interneurons, whose connections construct highly organized neuronal circuits that control higher order information processing. Recent progress in live imaging has allowed us to examine how these neurons differentiate during development in vivo or in in vivo-like conditions. These analyses have revealed how the initial steps of polarization, in which neurons establish an axon, occur. Interestingly, both excitatory and inhibitory cortical neurons establish neuronal polarity de novo by undergoing a multipolar stage reminiscent of the manner in which polarity formation occurs in hippocampal neurons in dissociated culture. In this review, we focus on polarity formation in cortical neurons and describe their typical morphology and dynamic behavior during the polarization period. We also discuss cellular and molecular mechanisms underlying polarization, with reference to polarity formation in dissociated hippocampal neurons in vitro. PMID:25904841

  8. Neuroprotective effects of active ingredients isolated from Pegasus laternarius on cultured cerebral neurons.

    PubMed

    Li, Mengtao; Chen, Minhui; Huang, Hai; Tao, Wucheng; Cui, Jihong; Xiang, Hui

    2011-01-01

    Seamoth (Pegasus laternarius Cuvier) is extensively used to treat various diseases on the coastland of Guangdong Province in China, such as scrofula, cough, and diarrhea. The total extract of Pegasus laternarius (EP) was subjected to column chromatography to acquire three different constituents (EPC1, EPC2, and EPC3). Cerebral neuron injury was induced by glutamate, H₂O₂, and serum deprivation. After treating with or without different extracts, cell viability was assessed with the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, and cell apoptosis was analyzed with Hoechst 33258 staining and agarose gel electrophoresis. We also determined the levels of lactate dehydrogenase (LDH), maleic dialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). The results showed that both EP and EPC2 promoted the outgrowth of cultural neurons, increased antioxidant enzyme activity, and protected neurons from neuronal injury or apoptosis induced by glutamate, H₂O₂, and serum deprivation. EPC1 and EPC3 had little or no effect on neurons. These results suggest that the active ingredients obtained from Pegasus laternarius have potential neuroprotective effects on injured neurons by promoting the outgrowth of cultured neurons, increasing the activity of intracellular antioxidants, and exerting antiapoptotic effects. This neuroprotection may be attributable to specific active ingredients, such as taurine, novel ceramide, and cholesterol.

  9. TGF-β1/Smad3 Signaling Pathway Suppresses Cell Apoptosis in Cerebral Ischemic Stroke Rats

    PubMed Central

    Zhu, Haiping; Gui, Qunfeng; Hui, Xiaobo; Wang, Xiaodong; Jiang, Jian; Ding, Lianshu; Sun, Xiaoyang; Wang, Yanping; Chen, Huaqun

    2017-01-01

    Background We desired to observe the changes of transforming growth factor-β1/drosophila mothers against decapentaplegic protein (TGF-β1/Smad3) signaling pathway in the hippocampus region of cerebral ischemic stroke rats so that the effects of this pathway on nerve cells can be investigated. Material/Methods The ischemic stroke models were built by middle cerebral artery occlusion (MCAO) in vivo and oxygen-glucose deprivation (OGD) in vitro. TGF-β1 and TGF-β1 inhibitors were injected into rat models while TGF-β1, TGF-β1 siRNA, Smad3, and Smad3 siRNA were transfected into cells. Infarct sizes were measured using triphenyltetrazolium chloride (TTC) staining, while the apoptosis rate of cells were calculated by Annexin V-fluorescein isothiocyanate/propidium iodide (Annexin V-FITC/PI) staining. Levels of TGF-β1, Smad3, and Bcl-2 were examined by real-time polymerase chain reaction (RT-PCR), immunohistochemical, and Western blot analysis. Results The expressions of TGF-β1/Smad3 signal pathway were significantly increased in both model rats and BV2 cells, whereas the expression of Bcl-2 was down-regulated (P<0.05). The TGF-β1/Smad3 signal pathway exhibited protective effects, including the down-regulation of infarction size in cerebral tissues and the down-regulation of apoptosis rate of BV2 cells by increasing the expression of Bcl-2 (P<0.05). In addition, these effects could be antagonized by the corresponding inhibitors and siRNA (P<0.05). Conclusions The TGF-β1/Smad3 signaling pathway was up-regulated once cerebral ischemic stroke was simulated. TGF-β1 may activate the expression of Bcl-2 via Smad3 to suppress the apoptosis of neurons. PMID:28110342

  10. Cold-inducible RNA-binding protein inhibits neuron apoptosis through the suppression of mitochondrial apoptosis.

    PubMed

    Zhang, Hai-Tao; Xue, Jing-Hui; Zhang, Zhi-Wen; Kong, Hai-Bo; Liu, Ai-Jun; Li, Shou-Chun; Xu, Dong-Gang

    2015-10-05

    Cold-inducible RNA-binding protein (CIRP) is induced by mild hypothermia in several mammals, but the precise mechanism by which CIRP mediates hypothermia-induced neuroprotection remains unknown. We aimed to investigate the molecular mechanisms by which CIRP protects the nervous system during mild hypothermia. Rat cortical neurons were isolated and cultured in vitro under mild hypothermia (32°C). Apoptosis was measured by annexin V and propidium iodide staining, visualized by flow cytometry. Neuron ultrastructure was visualized by transmission electron microscopy. CIRP overexpression and knockdown were achieved via infection with pL/IRES/GFP-CIRP and pL/shRNA/F-CIRP-A lentivirus. RT(2) Profiler PCR Array Pathway Analysis and western blotting were used to evaluate the effects of CIRP overexpresion/knockdown on the neurons׳ transcriptome. Neuron late apoptosis was significantly reduced at day 7 of culture by 12h hypothermia, but neuron ultrastructure remained relatively intact. RT(2) Profiler PCR Array Pathway Analysis of 84 apoptosis pathway-associated factors revealed that mild hypothermia and CIRP overexpression induce similar gene expression profiles, specifically alterations of genes implicated in the mitochondrial apoptosis pathway. Mild hypothermia-treated neurons up-regulated 12 and down-regulated 38 apoptosis pathway-associated genes. CIRP-overexpressing neurons up-regulated 15 and down-regulated 46 genes. CIRP-knocked-down hypothermia-treated cells up-regulated 9 and down-regulated 40 genes. Similar results were obtained at the protein level. In conclusion, CIRP may inhibit neuron apoptosis through the suppression of the mitochondria apoptosis pathway during mild hypothermia.

  11. Pink1 protects cortical neurons from thapsigargin-induced oxidative stress and neuronal apoptosis

    PubMed Central

    Li, Lin; Hu, Guo-ku

    2015-01-01

    Apoptosis mediates the precise and programmed natural death of neurons and is a physiologically important process in neurogenesis during maturation of the central nervous system. However, premature apoptosis and/or an aberration in apoptosis regulation are implicated in the pathogenesis of neurodegeneration. Thus, it is important to identify neuronal pathways/factors controlling apoptosis. Pink1 [phosphatase and tensin homologue (PTEN)-induced kinase 1] is a ubiquitously expressed gene and has been reported to have a physiological role in mitochondrial maintenance, suppressing mitochondrial oxidative stress, fission and autophagy. However, how Pink1 is involved in neuronal survival against oxidative stress remains not well understood. In the present paper, we demonstrate that thapsigargin, a specific irreversible inhibitor of endoplasmic reticulum (ER) calcium-ATPase, could lead to dramatic oxidative stress and neuronal apoptosis by ectopic calcium entry. Importantly, the neuronal toxicity of thapsigargin inhibits antioxidant gene Pink1 expression. Although Pink1 knockdown enhances the neuronal apoptosis by thapsigargin, its overexpression restores it. Our findings have established the neuronal protective role of Pink1 against oxidative stress and afford rationale for developing new strategy to the therapy of neurodegenerative diseases. PMID:25608948

  12. Effects of Maternal Antenatal Glucocorticoid Treatment on Apoptosis in the Ovine Fetal Cerebral Cortex

    PubMed Central

    Malaeb, Shadi N.; Hovanesian, Virginia; Sarasin, Matthew D.; Hartmann, Silvia M.; Sadowska, Grazyna B.; Stonestreet, Barbara S.

    2009-01-01

    We examined the effects of single and multiple maternal glucocorticoid courses on apoptosis in the cerebral cortices of ovine fetuses (CC). Ewes received single dexamethasone or placebo courses at 104–106 or 133–135 days or multiple courses between 76–78 and 104–106 days gestation. In the single-course groups, ewes received four 6 mg dexamethasone or placebo injections every 12 hr for 48 hr. Multiple-course groups received the same treatment once per week for 5 weeks. Neuronal and nonneuronal apoptotic cell numbers per square millimeter were determined with TUNEL and NeuN staining and with caspase-3 enzyme activity on CC tissues harvested at 106–108 (70%) or 135–137 (90%) days of gestation. Apoptotic cell numbers and caspase-3 activity were 50% lower (P < 0.02) after single placebo courses at 90% than 70% gestation; 90% of apoptotic cells were (P < 0.01) nonneuronal at both ages. Nonneuronal apoptotic cells and caspase-3 activity were 40% and 20% lower (P < 0.02) after single dexamethasone than placebo courses at 70%, but not 90%, gestation. Caspase-3 activity was 20% lower (P < 0.01) after multiple dexamethasone than placebo courses, but apoptotic cell number did not differ. We conclude that nonneuronal apoptosis represents the major form of apoptosis in the CC at both 70% and 90% of gestation. Apoptosis in nonneuronal cells decreases with maturity and after a single course of dexamethasone at 70%, but not at 90%, gestation and not after multiple courses at 70% gestation. We speculate that a single course of glucocorticoids exerts maturational changes on the rate of apoptosis in the cerebral cortex of preterm ovine fetuses. PMID:18711727

  13. Neurotrophin signalling pathways regulating neuronal apoptosis.

    PubMed

    Miller, F D; Kaplan, D R

    2001-07-01

    Recent evidence indicates that naturally occurring neuronal death in mammals is regulated by the interplay between receptor-mediated prosurvival and proapoptotic signals. The neurotrophins, a family of growth factors best known for their positive effects on neuronal biology, have now been shown to mediate both positive and negative survival signals, by signalling through the Trk and p75 neurotrophin receptors, respectively. The mechanisms whereby these two neurotrophin receptors interact to determine neuronal survival have been difficult to decipher, largely because both can signal independently or coincidentally, depending upon the cell or developmental context. Nonetheless, the past several years have seen significant advances in our understanding of this receptor signalling system. In this review, we focus on the proapoptotic actions of the p75 neurotrophin receptor (p75NTR), and on the interplay between Trk and p75NTR that determines neuronal survival.

  14. Cocaine induces apoptosis in cerebral vascular muscle cells: potential roles in strokes and brain damage.

    PubMed

    Su, Jialin; Li, Jianfeng; Li, Wenyan; Altura, Bella T; Altura, Burton M

    2003-12-15

    Cocaine abuse is known to induce different types of brain-microvascular damage and many adverse cerebrovascular effects, including cerebral vasculitis, intracranial hemorrhage, cerebral infarction and stroke. A major physiological event leading to these pathophysiological actions of cocaine could be apoptosis. Whether cocaine can cause brain-microvascular pathology and vascular toxicity by inducing apoptosis of cerebral vascular smooth muscle cells is not known. This study, using several different methods to discern apoptosis, was designed to investigate if primary cultured canine cerebral vascular smooth muscle cells can undergo apoptosis when treated with cocaine. After treatment with cocaine (10(-6)-10(-3) M) for 12-24 h, the death rates of cerebral vascular smooth muscle cells increased in a concentration-dependent manner compared with controls. Morphological analysis of cerebral vascular smooth muscle cells using confocal fluoresence microscopy showed that the percentage of apoptotic cerebral vascular smooth muscle cells increased after cocaine (10(-6)-10(-3) M) treatment in a concentration-dependent manner. TUNEL assays also showed positive results for cerebral vascular smooth muscle cells treated with cocaine. These results clearly demonstrate that cerebral vascular smooth muscle cells can undergo rapid apoptosis in response to cocaine in a concentration-dependent manner. Cocaine-induced apoptosis may thus play a major role in brain-microvascular damage, cerebral vascular toxicity and strokes.

  15. Strategies for analyzing neuronal progenitor development and neuronal migration in the developing cerebral cortex.

    PubMed

    Higginbotham, Holden; Yokota, Yukako; Anton, E S

    2011-07-01

    The emergence of functional neuronal connectivity in the developing cerebral cortex depends on 1) neural progenitor differentiation, which leads to the generation of appropriate number and types of neurons, and 2) neuronal migration, which enables the appropriate positioning of neurons so that the correct patterns of functional synaptic connectivity between neurons can emerge. In this review, we discuss 1) currently available methods to study neural progenitor development and differentiation in the developing cerebral cortex and emerging technologies in this regard, 2) assays to study the migration of descendents of progenitors (i.e., neurons) in vitro and in vivo, and 3) the use of these assays to probe the molecular control of these events in the developing brain and evaluation of gene functions disrupted in human neurodevelopmental disorders.

  16. Lower motor neuron facial palsy in cerebral venous sinus thrombosis

    PubMed Central

    Kulkarni, Girish Baburao; Ravi, Yadav; Nagaraja, Dindigur; Veerendrakumar, Mustare

    2013-01-01

    With advances in the neuro-imaging modalities, diverse manifestations of the cerebral venous sinus thrombosis (CVT) are being recognized. There are very few reports of isolated cranial nerve palsies in CVT. In this case report, we describe a patient of lower motor neuron facial palsy with CVT who was successfully treated with anticoagulation, highlighting the atypical manifestation of the disease. PMID:23914113

  17. Neonatal neuronal apoptosis after betamethasone administration in pregnant Wistar rats.

    PubMed

    França, Marcelo Santucci; Moron, Antonio Fernandes; Araujo Júnior, Edward; Avedissian, Marcelo; Pares, David Baptista Silva; Nardozza, Luciano Marcondes Marchado; Jaqueta, Carolina Barros; Mello, Luiz Eugênio Araujo Moraes

    2016-01-01

    To analyze the apoptosis of cortical and hippocampal neurons in newborn following the intramuscular administration of betamethasone in pregnant Wistar rats. Betamethasone or placebo was administered to 10 pregnant rats. Subsequently, 98 newborns were analyzed in three different groups: therapeutic dose (TD, 20 mg/kg), triple therapeutic dose (3TD, 60 mg/kg), and nine times TD (9TD, 180 mg/kg). Forty-four newborns were injected with placebo (control subjects--CTR). Neuronal apoptosis was measured by immunofluorescence using the TUNEL assay. The one-way analysis of variance, Tukey-Kramer (parametric) test and Kruskal-Wallis (non-parametric) test were used for statistical analysis. The CA1 area of the hippocampus of TD and 3TD groups showed significant differences from that of the CTR group (p < 0.001). Compared to the CTR group, there was increased neuronal apoptosis in the dentate gyrus (DG) of animals in TD and 3TD groups (p < 0.0001). There were no significant differences in CA2 and CA3 regions as well as in amygdala and cortex. Prenatal administration of betamethasone leads to significant changes in neuronal apoptosis in CA1 and DG regions.

  18. Calcium-sensing receptor antagonist NPS2390 attenuates neuronal apoptosis though intrinsic pathway following traumatic brain injury in rats.

    PubMed

    Xue, Zhaoliang; Song, Zhengfei; Wan, Yingfeng; Wang, Kun; Mo, Lianjie; Wang, Yirong

    2017-03-20

    Traumatic brain injury (TBI) initiates a complex cascade of neurochemical and signaling changes that leads to neuronal apoptosis, which contributes to poor outcomes for patients with TBI. Previous study indicates that calcium-sensing receptor (CaSR) activation contributes to neuron death in focal cerebral ischemia-reperfusion mice, however, its role in neuronal apoptosis after TBI is not well-established. Using a controlled cortical impact model in rats, the present study was designed to determine the effect of CaSR inhibitor NPS2390 upon neuronal apoptosis after TBI. Rats were randomly distributed into three groups undergoing the sham surgery or TBI procedure, and NPS2390 (1.5 mg/kg) was infused subcutaneously at 30 min and 120 min after TBI. All rats were sacrificed at 24 h after TBI. Our data indicated that NPS2390 significantly reduced the brain edema and improved the neurological function after TBI. In addition, NPS2390 decreased caspase-3 levels and the number of apoptotic neurons. Furthermore, NPS2390 up-regulated anti-apoptotic protein Bcl-2 expression and down-regulated pro-apoptotic protein Bax, and reduced subsequent release of cytochrome c into the cytosol. In summary, this study indicated that inhibition of CaSR by NPS2390 attenuates neuronal apoptosis after TBI, in part, through modulating intrinsic apoptotic pathway.

  19. Matrine attenuates focal cerebral ischemic injury by improving antioxidant activity and inhibiting apoptosis in mice

    PubMed Central

    ZHAO, PENG; ZHOU, RU; ZHU, XIAO-YUN; HAO, YIN-JU; LI, NAN; WANG, JIE; NIU, YANG; SUN, TAO; LI, YU-XIANG; YU, JIAN-QIANG

    2015-01-01

    Matrine, an active constituent of the Chinese herb, Sophora flavescens Ait., and it is known for its antioxidant, anti-inflammatory and antitumor activities. It has been demonstrated that matrine exerts protective effects against heart failure by decreasing the expression of caspase-3 and Bax, and increasing Bcl-2 levels. In this study, we aimed to determine whether these protective effects of matrine can be applied to cerebral ischemia. Following 7 successive days of treatment with matrine (7.5, 15 and 30 mg/kg) and nimodipine (1 mg/kg) by intraperitoneal injection, male Institute of Cancer Research (ICR) mice were subjected to middle cerebral artery occlusion (MCAO). Following reperfusion, the neurobehavioral score and brain infarct volume were estimated, and morphological changes were analyzed by hematoxylin and eosin (H&E) staining and electron microscopy. The percentage of apoptotic neurons was determined by flow cytometry. The levels of oxidative stress were assessed by measuring the levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), and the total antioxidant capacity (T-AOC). Western blot analysis and immunofluorescence staining were used to examine the expression of the apoptosis-related proteins, caspase-3, Bax and Bcl-2. Our results revealed that pre-treatment with matrine significantly decreased the infarct volume and improved the neurological scores. Matrine also reduced the percentage of apoptotic neurons and relieved neuronal morphological damage. Furthermore, matrine markedly decreased the MDA levels, and increased SOD, GSH-Px and CAT activity, and T-AOC. Western blot analysis and immunofluorescence staining revealed a marked decrease in caspase-3 expression and an increase in the Bcl-2/Bax ratio in the group pre-treated with matrine (30 mg/kg) as compared with the vehicle-treated group. The findings of the present study demonstrate that matrine exerts neuroprotective effects against

  20. Mechanisms of Neuronal Apoptosis In Vivo

    DTIC Science & Technology

    2004-02-01

    typically regarded as selectively vulnerable to ischemia (Martin et al., 2000). For example, subsets of granule cells in the dentate gyrus, subsets of... granule cells in the cerebellar cortex, and certain neurons in thalamic nuclear groups appear apoptotic. In addition, prominent apoptotic death of white...Jr (1997) Bax deletion Kermer P., Kl6cker N., Labes M. and Blhr M. (1998) Inhibition of further orders the cell death pathway in cerebellar granule

  1. Effects of caffeine on neuronal apoptosis in neonatal hypoxic-ischemic brain injury.

    PubMed

    Kilicdag, Hasan; Daglioglu, Yusuf Kenan; Erdogan, Seyda; Zorludemir, Suzan

    2014-09-01

    Hypoxia-ischemia (HI) in rat pups leads to strong activation of apoptosis, and apoptosis contributes significantly to cerebral damage in the perinatal period. Caffeine displays a broad array of actions on the brain. The aim of this study was to investigate the effects of caffeine on neuronal apoptosis in a hypoxic-ischemic neonatal model. Twenty-four seven-day-old Wistar rat pups were subjected to right common carotid artery ligation and hypoxia for 2 h. Sham group (n = 8) had a median neck incision, but the rats were not subjected to ligation or hypoxia. The pups were treated with 20 mg/kg/day caffeine citrate (n = 8) or saline (n = 8) immediately before HI and at 0, 24, 48 and 72 h post-hypoxia. Neuronal apoptosis was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) and caspase-3 in the hippocampus and parietal cortex of both hemispheres. The numbers of apoptotic cells in the hippocampus and parietal cortex were significantly higher in the saline group than they were in the sham group (p < 0.0001). The number of apoptotic cells in the hippocampus (p < 0.0001) and parietal cortex (p < 0.0001, TUNEL and p = 0.001, caspase-3) were higher in the caffeine-treated group than they were in the sham group, but the number of apoptotic cells decreased significantly in the caffeine-treated group compared with the saline group in the hippocampus (p < 0.0001, TUNEL and p = 0.001, caspase-3) and parietal cortex (p = 0.001, TUNEL and p = 0.002, caspase-3). We show that caffeine administration in hypoxic-ischemic brain injury reduces neuronal apoptosis in the developing brain. We suggest that caffeine may be effective in reducing brain injury.

  2. GnRH analogue attenuated apoptosis of rat hippocampal neuron after ischemia-reperfusion injury.

    PubMed

    Chu, Chenyu; Xu, Bainan; Huang, Weiquan

    2010-12-01

    The expression and new functions of reproductive hormones in organs beyond hypothalamus-pituitary-gonad axis have been reported. So far, there is no report about the protective effects of GnRH analogue to hippocampal neurons suffering from ischemia-reperfusion injury. Middle cerebral artery occlusion model together with TUNEL staining were made in vivo and oxygen-glucose deprivation model together with double staining of Annexin V/PI with flow cytometer were made in vitro to observe the anti-apoptotic effects of GnRH analogue to hippocampal neurons after ischemia-reperfusion injury. The results found that the number of TUNEL positive pyramidal neurons in CA1 region in GnRH analogue experiment group was less than that in control group in vivo; the percentage of apoptotic neurons in GnRH analogue experiment group was less than that in control group in vitro. These findings suggested that pretreatment with certain concentration of GnRH analogue could attenuate apoptosis of hippocampal neurons. GnRH analogue has the protective effects to neurons.

  3. Prenatal cerebral ischemia triggers dysmaturation of caudate projection neurons

    PubMed Central

    McClendon, Evelyn; Chen, Kevin; Gong, Xi; Sharifnia, Elica; Hagen, Matthew; Cai, Victor; Shaver, Daniel C.; Riddle, Art; Dean, Justin M.; Gunn, Alistair J.; Mohr, Claudia; Kaplan, Joshua S.; Rossi, David J.; Kroenke, Christopher D.; Hohimer, A. Roger; Back, Stephen A.

    2014-01-01

    Objective Recently we reported that the neocortex displays impaired growth after transient cerebral hypoxia-ischemia (HI) at preterm gestation that is unrelated to neuronal death but is associated with decreased dendritic arbor complexity of cortical projection neurons. We hypothesized that these morphological changes constituted part of a more widespread neuronal dysmaturation response to HI in the caudate nucleus (CN), which contributes to motor and cognitive disability in preterm survivors. Methods Ex vivo magnetic resonance imaging (MRI), immunohistochemistry and Golgi staining defined CN growth, cell death, proliferation and dendritic maturation in preterm fetal sheep four weeks after HI. Patch-clamping recording was used to analyze glutamatergic synaptic currents in CN neurons. Results MRI-defined growth of the CN was reduced after ischemia compared to controls. However, no significant acute or delayed neuronal death was seen in the CN or white matter. Neither was there significant loss of calbindin-positive medium spiny projection neurons (MSNs) or CN interneurons expressing somatostatin, calretinin, parvalbumin, or tyrosine hydroxylase. Morphologically, ischemic MSNs showed a markedly immature dendritic arbor, with fewer dendritic branches, nodes, endings and spines. The magnitude and kinetics of synaptic currents, and the relative contribution of glutamate receptor subtypes in the CN were significantly altered. Interpretation The marked MSN dendritic and functional abnormalities after preterm cerebral HI, despite the marked resistance of immature CN neurons to cell death, are consistent with widespread susceptibility of projection neurons to HI-induced dysmaturation. These global disturbances in dendritic maturation and glutamatergic synaptic transmission suggest a new mechanism for long-term motor and behavioral disabilities in preterm survivors via widespread disruption of neuronal connectivity. PMID:24395459

  4. Activation of autophagy at cerebral cortex and apoptosis at brainstem are differential responses to 835 MHz RF-EMF exposure.

    PubMed

    Kim, Ju Hwan; Yu, Da-Hyeon; Kim, Hak Rim

    2017-03-01

    With the explosive increase in exposure to radiofrequency electromagnetic fields (RF-EMF) emitted by mobile phones, public concerns have grown over the last few decades with regard to the potential effects of EMF exposure on the nervous system in the brain. Many researchers have suggested that RF-EMFs can effect diverse neuronal alterations in the brain, thereby affecting neuronal functions as well as behavior. Previously, we showed that long-term exposure to 835 MHz RF-EMF induces autophagy in the mice brain. In this study, we explore whether short-term exposure to RF-EMF leads to the autophagy pathway in the cerebral cortex and brainstem at 835 MHz with a specific absorption rate (SAR) of 4.0 W/kg for 4 weeks. Increased levels of autophagy genes and proteins such as LC3B-II and Beclin1 were demonstrated and the accumulation of autophagosomes and autolysosomes was observed in cortical neurons whereas apoptosis pathways were up-regulated in the brainstem but not in the cortex following 4 weeks of RF exposure. Taken together, the present study indicates that monthly exposure to RF-EMF induces autophagy in the cerebral cortex and suggests that autophagic degradation in cortical neurons against a stress of 835 MHz RF during 4 weeks could correspond to adaptation to the RF stress environment. However, activation of apoptosis rather than autophagy in the brainstem is suggesting the differential responses to the RF-EMF stresses in the brain system.

  5. Activation of autophagy at cerebral cortex and apoptosis at brainstem are differential responses to 835 MHz RF-EMF exposure

    PubMed Central

    Kim, Ju Hwan; Yu, Da-Hyeon

    2017-01-01

    With the explosive increase in exposure to radiofrequency electromagnetic fields (RF-EMF) emitted by mobile phones, public concerns have grown over the last few decades with regard to the potential effects of EMF exposure on the nervous system in the brain. Many researchers have suggested that RF-EMFs can effect diverse neuronal alterations in the brain, thereby affecting neuronal functions as well as behavior. Previously, we showed that long-term exposure to 835 MHz RF-EMF induces autophagy in the mice brain. In this study, we explore whether short-term exposure to RF-EMF leads to the autophagy pathway in the cerebral cortex and brainstem at 835 MHz with a specific absorption rate (SAR) of 4.0 W/kg for 4 weeks. Increased levels of autophagy genes and proteins such as LC3B-II and Beclin1 were demonstrated and the accumulation of autophagosomes and autolysosomes was observed in cortical neurons whereas apoptosis pathways were up-regulated in the brainstem but not in the cortex following 4 weeks of RF exposure. Taken together, the present study indicates that monthly exposure to RF-EMF induces autophagy in the cerebral cortex and suggests that autophagic degradation in cortical neurons against a stress of 835 MHz RF during 4 weeks could correspond to adaptation to the RF stress environment. However, activation of apoptosis rather than autophagy in the brainstem is suggesting the differential responses to the RF-EMF stresses in the brain system. PMID:28280411

  6. Retinoblastoma protein controls growth, survival and neuronal migration in human cerebral organoids.

    PubMed

    Matsui, Takeshi; Nieto-Estévez, Vanesa; Kyrychenko, Sergii; Schneider, Jay W; Hsieh, Jenny

    2017-03-15

    The tumor suppressor retinoblastoma protein (RB) regulates S-phase cell cycle entry via E2F transcription factors. Knockout (KO) mice have shown that RB plays roles in cell migration, differentiation and apoptosis, in developing and adult brain. In addition, the RB family is required for self-renewal and survival of human embryonic stem cells (hESCs). Since little is known about the role of RB in human brain development, we investigated its function in cerebral organoids differentiated from gene-edited hESCs lacking RB. We show that RB is abundantly expressed in neural stem and progenitor cells in organoids at 15 and 28 days of culture. RB loss promoted S-phase entry in DCX(+) cells and increased apoptosis in Sox2(+) neural stem and progenitor cells, and in DCX(+) and Tuj1(+) neurons. Associated with these cell cycle and pro-apoptotic effects, we observed increased CCNA2 and BAX gene expression, respectively. Moreover, we observed aberrant Tuj1(+) neuronal migration in RB-KO organoids and upregulation of the gene encoding VLDLR, a receptor important in reelin signaling. Corroborating the results in RB-KO organoids in vitro, we observed ectopically localized Tuj1(+) cells in RB-KO teratomas grown in vivo Taken together, these results identify crucial functions for RB in the cerebral organoid model of human brain development. © 2017. Published by The Company of Biologists Ltd.

  7. Motor neuron disease: biomarker development for an expanding cerebral syndrome.

    PubMed

    Turner, Martin R

    2016-12-01

    Descriptions of motor neuron disease (MND) documented more than a century ago remain instantly recognisable to the physician. The muscle weakness, typically with signs of upper and lower motor neuron dysfunction, is uniquely relentless. Over the last 30 years, a wider cerebral pathology has emerged, despite the lack of overt cognitive impairment in the majority of patients. From the initial linkage of a small number of cases to mutations in SOD1, diverse cellular pathways have been implicated in pathogenesis. An increasingly complex clinical heterogeneity has emerged around a significant variability in survival. Defining a cellular signature of aggregated TDP-43 common to nearly all MND and a large proportion of frontotemporal dementia (FTD), has placed MND alongside more traditional cerebral neurodegeneration. With new genetic causes, most notably a hexanucleotide expansion in C9orf72 associated with both MND and FTD, the development of biomarkers against which to test therapeutic candidates is a priority.

  8. Neuronal apoptosis and gray matter heterotopia in microcephaly produced by cytosine arabinoside in mice.

    PubMed

    Takano, Tomoyuki; Akahori, Shie; Takeuchi, Yoshihiro; Ohno, Masaki

    2006-05-17

    Primary microcephaly can be accompanied by numerous migration anomalies. This experiment was undertaken to examine the pathogenesis of gray matter heterotopia and microcephaly that is produced after administering cytosine arabinoside (Ara-C) to mice. Pregnant mice were intraperitoneally injected with Ara-C at 30 mg/kg body weight on days 13.5 and 14.5 of gestation, and then their offspring were examined. On embryonic day 15.5, in the ventricular zone of the cingulate cortex, the neuroepithelial cells lacked BrdU immunoreactivity. Nestin-immunoreactive radial glial fibers and calretinin-positive subplate fibers were disrupted. TUNEL reaction was remarkable throughout the cerebral hemisphere. Subcortical heterotopia in the cingulate cortex and subependymal nodular heterotopia in the dorsolateral part of the lateral ventricles became detectable by the first day after birth. Thirty-two days after birth, microcephaly was apparent; subcortical heterotopia was observed to have increased in size while it was still located in the frontal and cingulate cortices. This experiment demonstrated that Ara-C induces neuronal apoptosis throughout the cerebral hemisphere. The immunohistochemical characteristics in the gray matter heterotopia suggest that both the subcortical and the subependymal heterotopias were formed by neurons originally committed to the neocortex. We conclude that the gray matter heterotopia that accompanies the microcephaly was produced by a disturbance of radial, tangential, and interkinetic neuronal migrations due to the toxicity of Ara-C in the immature developing brain.

  9. Ketamine-induced apoptosis in cultured rat cortical neurons

    SciTech Connect

    Takadera, Tsuneo . E-mail: t-takadera@hokuriku-u.ac.jp; Ishida, Akira; Ohyashiki, Takao

    2006-01-15

    Recent data suggest that anesthetic drugs cause neurodegeneration during development. Ketamine is frequently used in infants and toddlers for elective surgeries. The purpose of this study is to determine whether glycogen synthase kinase-3 (GSK-3) is involved in ketamine-induced apoptosis. Ketamine increased apoptotic cell death with morphological changes which were characterized by cell shrinkage, nuclear condensation or fragmentation. In addition, insulin growth factor-1 completely blocked the ketamine-induced apoptotic cell death. Ketamine decreased Akt phosphorylation. GSK-3 is known as a downstream target of Akt. The selective inhibitors of GSK-3 prevented the ketamine-induced apoptosis. Moreover, caspase-3 activation was accompanied by the ketamine-induced cell death and inhibited by the GSK-3 inhibitors. These results suggest that activation of GSK-3 is involved in ketamine-induced apoptosis in rat cortical neurons.

  10. Transport of L-carnitine in isolated cerebral cortex neurons.

    PubMed

    Wawrzeńczyk, A; Sacher, A; Mac, M; Nałecz, M J; Nałecz, K A

    2001-04-01

    The accumulation of carnitine was measured in cerebral cortex neurons isolated from adult rat brain. This process was found to be lowered by 40% after preincubation with ouabain and with SH-group reagents (N-ethylmaleimide and mersalyl). The initial velocity of carnitine transport was found to be inhibited by 4-aminobutyrate (GABA) in a competitive way (Ki = 20.9 +/- 2.4 mM). However, of various inhibitors of GABA transporters, only nipecotic acid and very high concentrations of 1-[2-([(diphenylmethylene)amino]oxy)ethyl]-1,2,5,6-tetrahydro-3-pyridinecarboxylic acid hydrochloride (NO-711) acid decreased carnitine accumulation while betaine, taurine and beta-alanine had no effect. The GABA transporters expressed in Xenopus laevis oocytes did not transport carnitine. Moreover, carnitine was not observed to diminish the accumulation of GABA in cerebral cortex neurons, which further excluded a possible involvement of the GABA transporter GAT1 in the process of carnitine accumulation, despite the expression of this protein in the cells under study. The absence of carnitine transporter OCTN2 in rat cerebral cortex neurons (K. A. Nałecz, D. Dymna, J. E. Mroczkowska, A. Broër, S. Broër, M. J. Nałecz and R. Cecchelli, unpublished results), together with the insensitivity of carnitine accumulation towards betaines, implies that a novel transporting protein is present in these cells.

  11. PUMA is invovled in ischemia/reperfusion-induced apoptosis of mouse cerebral astrocytes.

    PubMed

    Chen, H; Tian, M; Jin, L; Jia, H; Jin, Y

    2015-01-22

    PUMA (p53-upregulated modulator of apoptosis), a BH3-only member of the Bcl-2 protein family, is required for p53-dependent and p53-independent forms of apoptosis. PUMA has been invovled in the onset and progress of several diseases, including cancer, acquired immunodeficiency syndrome, and ischemic brain disease. Although many studies have shown that ischemia and reperfusion (I/R) can induce the apoptosis of astrocytes, the role of PUMA in I/R-mediated apoptosis of cerebral astrocyte apoptosis remains unclear. To mimic in vivo I/R conditions, primary mouse cerebral astrocytes were incubated in a combinational cultural condition of oxygen, glucose, and serum deprivation (OSGD) for 1 h followed by reperfusion (OSGD/R). Cell death determination assays and cell viability assays indicated that OSGD and OSGD/R induce the apoptosis of primary cerebral astrocytes. The expression of PUMA was significantly elevated in primary cerebral astrocytes during OSGD/R. Moreover, targeted down-regulation of PUMA by siRNA transfection significantly decreased the OSGD/R-induced apoptosis of primary cerebral astrocytes. We also found that OSGD and OSGD/R triggered the release of cytochrome c in astrocytes, indicating the dependence on a mitochondrial apoptotic pathway. Reactive oxygen species (ROS) was extremely generated during OSGD and OSGD/R, and the elimination of ROS by treated with N-acetyl-L-cysteine (NAC) remarkably inhibited the expression of PUMA and the apoptosis of primary cerebral astrocytes. The activation of Caspase 3 and Caspase 9 was extremely elevated in primary cerebral astrocytes during OSGD. In addition, we found that knockdown of PUMA led to the depressed expression of Bax, cleaved caspase-9 and caspase-3 during OSGD/R. These results indicate that PUMA is invovled in the apoptosis of cerebral astrocytes upon I/R injury.

  12. Pipoxolan Ameliorates Cerebral Ischemia via Inhibition of Neuronal Apoptosis and Intimal Hyperplasia through Attenuation of VSMC Migration and Modulation of Matrix Metalloproteinase-2/9 and Ras/MEK/ERK Signaling Pathways

    PubMed Central

    Chen, Yuh-Fung; Tsai, Huei-Yann; Wu, Kuo-Jen; Siao, Lian-Ru; Wood, W. Gibson

    2013-01-01

    Pipoxolan (PIPO) has anti-spasmodic effects, and it is used clinically to relieve smooth muscle spasms. Cerebrovascular disease is one of the leading causes of disability and death worldwide. The main aim of this study was to investigate the effects of PIPO on cerebral ischemia and vascular smooth muscle cell (VSMC) migration in vivo and in vitro. Cerebral infarction area, ratio of intima to media area (I/M ratio) and PCNA antibody staining of the carotid artery in vivo were measured. Cell viability of A7r5 cells, PDGF-BB-stimulated cell migration, and potential mechanisms of PIPO were evaluated by wound healing, transwell and Western blotting. PIPO (10 and 30 mg/kg p.o.) reduced: the cerebral infarction area; neurological deficit; TUNEL-positive cells; cleaved caspase 3-positive cells; intimal hyperplasia; and inhibited proliferating cell nuclear antigen (PCNA)-positive cells in rodents. PIPO (5, 10 and 15 µM) significantly inhibited PDGF-BB-stimulated VSMC migration and reduced Ras, MEK, and p-ERK levels. Moreover, PIPO decreased levels of matrix metalloproteinases -2 and -9 in PDGF-BB-stimulated A7r5 cells. In summary, PIPO is protective in models of ischemia/reperfusion-induced cerebral infarction, carotid artery ligation-induced intimal hyperplasia and VSMC migration both in vivo and in vitro. PIPO could be potentially efficacious in preventing cerebrovascular and vascular diseases. PMID:24086601

  13. Pipoxolan ameliorates cerebral ischemia via inhibition of neuronal apoptosis and intimal hyperplasia through attenuation of VSMC migration and modulation of matrix metalloproteinase-2/9 and Ras/MEK/ERK signaling pathways.

    PubMed

    Chen, Yuh-Fung; Tsai, Huei-Yann; Wu, Kuo-Jen; Siao, Lian-Ru; Wood, W Gibson

    2013-01-01

    Pipoxolan (PIPO) has anti-spasmodic effects, and it is used clinically to relieve smooth muscle spasms. Cerebrovascular disease is one of the leading causes of disability and death worldwide. The main aim of this study was to investigate the effects of PIPO on cerebral ischemia and vascular smooth muscle cell (VSMC) migration in vivo and in vitro. Cerebral infarction area, ratio of intima to media area (I/M ratio) and PCNA antibody staining of the carotid artery in vivo were measured. Cell viability of A7r5 cells, PDGF-BB-stimulated cell migration, and potential mechanisms of PIPO were evaluated by wound healing, transwell and Western blotting. PIPO (10 and 30 mg/kg p.o.) reduced: the cerebral infarction area; neurological deficit; TUNEL-positive cells; cleaved caspase 3-positive cells; intimal hyperplasia; and inhibited proliferating cell nuclear antigen (PCNA)-positive cells in rodents. PIPO (5, 10 and 15 µM) significantly inhibited PDGF-BB-stimulated VSMC migration and reduced Ras, MEK, and p-ERK levels. Moreover, PIPO decreased levels of matrix metalloproteinases -2 and -9 in PDGF-BB-stimulated A7r5 cells. In summary, PIPO is protective in models of ischemia/reperfusion-induced cerebral infarction, carotid artery ligation-induced intimal hyperplasia and VSMC migration both in vivo and in vitro. PIPO could be potentially efficacious in preventing cerebrovascular and vascular diseases.

  14. Thrombin-induced apoptosis in neurons through activation of c-Jun-N-terminal kinase.

    PubMed

    Bao, Lei; Zu, Jie; He, Qianqian; Zhao, Hui; Zhou, Su; Ye, Xinchun; Yang, Xinxin; Zan, Kun; Zhang, Zuohui; Shi, Hongjuan; Cui, Guiyun

    2017-01-01

    Studies have shown that thrombin activation played a central role in cell injuries associated with intracerebral hemorrhage (ICH). Here, our study investigated the cytotoxicity of thrombin on neurons, and determined the involvement of JNK pathways in thrombin-induced neuronal apoptosis. Primary cultured neurons were treated with different doses of thrombin. Some neurons were given either SP600125 or vehicle. LDH release assay and flow cytometry were used to measure neuronal apoptosis caused by thrombin. The activation of JNK and capases-3 were measured by Western blot. Our results showed large doses of thrombin that increased the LDH release, the level of cleaved caspase-3 and apoptosis rate of neurons. JNK was activated by thrombin in a time-dependent manner. Administration of SP600125 protects neurons from thrombin-induced apoptosis. These data indicate that the activation of JNK is crucial for thrombin-induced neuronal apoptosis, and inhibition of JNK may be a potential therapeutic target for ICH.

  15. Neurotrophin 3 rescues neuronal precursors from apoptosis and promotes neuronal differentiation in the embryonic metanephric kidney.

    PubMed Central

    Karavanov, A; Sainio, K; Palgi, J; Saarma, M; Saxen, L; Sariola, H

    1995-01-01

    We analyzed the developmental regulation and role of the neurotrophins during metanephric kidney morphogenesis. RNase protection assay revealed the presence of nerve growth factor, neurotrophin 3 (NT-3), and brain-derived neurotrophic factor mRNAs and the regulation of their expression during embryonic development of rat metanephros. NT-3 induced differentiation (neurite outgrowth) and survival (inhibition of apoptosis) of the neuronal precursors in cultured nephrogenic mesenchymes and neuronal differentiation in cultured whole kidneys, whereas NT-4/5, brain-derived neurotrophic factor, and nerve growth factor were without effect. The neurotrophins did not trigger tubular differentiation of isolated nephrogenic cells, which underwent apoptosis when cultured with or without the neurotrophins. NT-3 is thus an inducer of differentiation and a survival factor for renal neuronal cells, but none of the neurotrophins is a morphogen in kidney tubule induction. Images Fig. 1 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:7479979

  16. Protective effect of nicotinamide adenine dinucleotide (NAD(+)) against spinal cord ischemia-reperfusion injury via reducing oxidative stress-induced neuronal apoptosis.

    PubMed

    Xie, Lei; Wang, Zhenfei; Li, Changwei; Yang, Kai; Liang, Yu

    2017-02-01

    As previous studies demonstrate that oxidative stress and apoptosis play crucial roles in ischemic pathogenesis and nicotinamide adenine dinucleotide (NAD(+)) treatment attenuates oxidative stress-induced cell death among primary neurons and astrocytes as well as significantly reduce cerebral ischemic injury in rats. We used a spinal cord ischemia injury (SCII) model in rats to verify our hypothesis that NAD(+) could ameliorate oxidative stress-induced neuronal apoptosis. Adult male rats were subjected to transient spinal cord ischemia for 60min, and different doses of NAD(+) were administered intraperitoneally immediately after the start of reperfusion. Neurological function was determined by Basso, Beattie, Bresnahan (BBB) scores. The oxidative stress level was assessed by superoxide dismutase (SOD) activity and malondialdehyde (MDA) content. The degree of apoptosis was analyzed by deoxyuridinetriphosphate nick-end labeling (TUNEL) staining and protein levels of cleaved caspase-3 and AIF (apoptosis inducing factor). The results showed that NAD(+) at 50 or 100mg/kg significantly decreased the oxidative stress level and neuronal apoptosis in the spinal cord of ischemia-reperfusion rats compared with saline, as accompanied with the decreased oxidative stress, NAD(+) administration significantly restrained the neuronal apoptosis after ischemia injury while improved the neurological and motor function. These findings suggested that NAD(+) might protect against spinal cord ischemia-reperfusion via reducing oxidative stress-induced neuronal apoptosis.

  17. Neuroprotective Effects of Sevoflurane against Electromagnetic Pulse-Induced Brain Injury through Inhibition of Neuronal Oxidative Stress and Apoptosis

    PubMed Central

    Wang, Jin; Han, Li-Chun; Li, Li-Ya; Wu, Guang-Li; Hou, Yan-Ning; Guo, Guo-Zhen; Wang, Qiang; Sang, Han-Fei; Xu, Li-Xian

    2014-01-01

    Electromagnetic pulse (EMP) causes central nervous system damage and neurobehavioral disorders, and sevoflurane protects the brain from ischemic injury. We investigated the effects of sevoflurane on EMP-induced brain injury. Rats were exposed to EMP and immediately treated with sevoflurane. The protective effects of sevoflurane were assessed by Nissl staining, Fluoro-Jade C staining and electron microscopy. The neurobehavioral effects were assessed using the open-field test and the Morris water maze. Finally, primary cerebral cortical neurons were exposed to EMP and incubated with different concentration of sevoflurane. The cellular viability, lactate dehydrogenase (LDH) release, superoxide dismutase (SOD) activity and malondialdehyde (MDA) level were assayed. TUNEL staining was performed, and the expression of apoptotic markers was determined. The cerebral cortexes of EMP-exposed rats presented neuronal abnormalities. Sevoflurane alleviated these effects, as well as the learning and memory deficits caused by EMP exposure. In vitro, cell viability was reduced and LDH release was increased after EMP exposure; treatment with sevoflurane ameliorated these effects. Additionally, sevoflurane increased SOD activity, decreased MDA levels and alleviated neuronal apoptosis by regulating the expression of cleaved caspase-3, Bax and Bcl-2. These findings demonstrate that Sevoflurane conferred neuroprotective effects against EMP radiation-induced brain damage by inhibiting neuronal oxidative stress and apoptosis. PMID:24614080

  18. Neuroprotective effects of sevoflurane against electromagnetic pulse-induced brain injury through inhibition of neuronal oxidative stress and apoptosis.

    PubMed

    Deng, Bin; Xu, Hao; Zhang, Jin; Wang, Jin; Han, Li-Chun; Li, Li-Ya; Wu, Guang-Li; Hou, Yan-Ning; Guo, Guo-Zhen; Wang, Qiang; Sang, Han-Fei; Xu, Li-Xian

    2014-01-01

    Electromagnetic pulse (EMP) causes central nervous system damage and neurobehavioral disorders, and sevoflurane protects the brain from ischemic injury. We investigated the effects of sevoflurane on EMP-induced brain injury. Rats were exposed to EMP and immediately treated with sevoflurane. The protective effects of sevoflurane were assessed by Nissl staining, Fluoro-Jade C staining and electron microscopy. The neurobehavioral effects were assessed using the open-field test and the Morris water maze. Finally, primary cerebral cortical neurons were exposed to EMP and incubated with different concentration of sevoflurane. The cellular viability, lactate dehydrogenase (LDH) release, superoxide dismutase (SOD) activity and malondialdehyde (MDA) level were assayed. TUNEL staining was performed, and the expression of apoptotic markers was determined. The cerebral cortexes of EMP-exposed rats presented neuronal abnormalities. Sevoflurane alleviated these effects, as well as the learning and memory deficits caused by EMP exposure. In vitro, cell viability was reduced and LDH release was increased after EMP exposure; treatment with sevoflurane ameliorated these effects. Additionally, sevoflurane increased SOD activity, decreased MDA levels and alleviated neuronal apoptosis by regulating the expression of cleaved caspase-3, Bax and Bcl-2. These findings demonstrate that Sevoflurane conferred neuroprotective effects against EMP radiation-induced brain damage by inhibiting neuronal oxidative stress and apoptosis.

  19. Overexpression of Nrf2 Protects Cerebral Cortical Neurons from Ethanol-Induced Apoptotic DeathS⃞

    PubMed Central

    Narasimhan, Madhusudhanan; Mahimainathan, Lenin; Rathinam, Mary Latha; Riar, Amanjot Kaur

    2011-01-01

    Ethanol (ETOH) can cause apoptotic death of neurons by depleting GSH with an associated increase in oxidative stress. The current study illustrates a means to overcome this ETOH-induced neurotoxicity by enhancing GSH through boosting Nrf2, a transcription factor that controls GSH homeostasis. ETOH treatment caused a significant increase in Nrf2 protein, transcript expression, Nrf2-DNA binding activity, and expression of its transcriptional target, NQO1, in primary cortical neuron (PCNs). However, this increase in Nrf2 did not maintain GSH levels in response to ETOH, and apoptotic death still occurred. To elucidate this phenomenon, we silenced Nrf2 in neurons and found that ETOH-induced GSH depletion and the increase in superoxide levels were exacerbated. Furthermore, Nrf2 knockdown resulted in significantly increased (P < 0.05) caspase 3 activity and apoptosis. Adenovirus-mediated overexpression of Nrf2 prevented ETOH-induced depletion of GSH from the medium and high GSH subpopulations and prevented ETOH-related apoptotic death. These studies illustrate the importance of Nrf2-dependent maintenance of GSH homeostasis in cerebral cortical neurons in the defense against oxidative stress and apoptotic death elicited by ETOH exposure. PMID:21873460

  20. Acute upregulation of neuronal mitochondrial type-1 cannabinoid receptor and it's role in metabolic defects and neuronal apoptosis after TBI.

    PubMed

    Xu, Zhen; Lv, Xiao-Ai; Dai, Qun; Ge, Yu-Qing; Xu, Jie

    2016-08-02

    Metabolic defects and neuronal apoptosis initiated by traumatic brain injury (TBI) contribute to subsequent neurodegeneration. They are all regulated by mechanisms centered around mitochondrion. Type-1 cannabinoid receptor (CB1) is a G-protein coupled receptor (GPCR) enriched on neuronal plasma membrane. Recent evidences point to the substantial presence of CB1 receptors on neuronal mitochondrial outer membranes (mtCB1) and the activation of mtCB1 influences aerobic respiration via inhibiting mitochondrial cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/complex I pathway. The expression and role of neuronal mtCB1 under TBI are unknown. Using TBI models of cultured neurons, wild type and CB1 knockout mice, we found mtCB1 quickly upregulated after TBI. Activation of mtCB1 promoted metabolic defects accompanied with ATP shortage but protected neurons from apoptosis. Selective activation of plasma membrane CB1 showed no effects on neuronal metabolism and apoptosis. Activation of mtCB1 receptors inhibited mitochondrial cAMP/PKA/complex I and resulted in exacerbated metabolic defects accompanied with a higher ratio of ATP reduction to oxygen consumption decrease as well as neuronal apoptosis. Further research found the remarkable accumulation of protein kinase B (AKT) on neuronal mitochondria following TBI and the activation of mtCB1 upregulated mitochondrial AKT/complex V activity. Upregulation of mitochondrial AKT/complex V activity showed anti-apoptosis effects and alleviated ATP shortage in metabolic defects. Taken together, we have identified mtCB1 quickly upregulate after TBI and a dual role the mtCB1 might play in metabolic defects and neuronal apoptosis initiated by TBI: the inhibition of mitochondrial cAMP/PKA/complex I aggravates metabolic defects, energy insufficiency as well as neuronal apoptosis, but the coactivation of mitochondrial AKT/complex V mitigates energy insufficiency and neuronal apoptosis.

  1. Erythropoietin reduces apoptosis of brain tissue cells in rats after cerebral ischemia/reperfusion injury: a characteristic analysis using magnetic resonance imaging.

    PubMed

    Jiang, Chun-Juan; Wang, Zhong-Juan; Zhao, Yan-Jun; Zhang, Zhui-Yang; Tao, Jing-Jing; Ma, Jian-Yong

    2016-09-01

    Some in vitro experiments have shown that erythropoietin (EPO) increases resistance to apoptosis and facilitates neuronal survival following cerebral ischemia. However, results from in vivo studies are rarely reported. Perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) have been applied successfully to distinguish acute cerebral ischemic necrosis and penumbra in living animals; therefore, we hypothesized that PWI and DWI could be used to provide imaging evidence in vivo for the conclusion that EPO could reduce apoptosis in brain areas injured by cerebral ischemia/reperfusion. To validate this hypothesis, we established a rat model of focal cerebral ischemia/reperfusion injury, and treated with intra-cerebroventricular injection of EPO (5,000 U/kg) 20 minutes before injury. Brain tissue in the ischemic injury zone was sampled using MRI-guided localization. The relative area of abnormal tissue, changes in PWI and DWI in the ischemic injury zone, and the number of apoptotic cells based on TdT-mediated dUTP-biotin nick end-labeling (TUNEL) were assessed. Our findings demonstrate that EPO reduces the relative area of abnormally high signal in PWI and DWI, increases cerebral blood volume, and decreases the number of apoptotic cells positive for TUNEL in the area injured by cerebral ischemia/reperfusion. The experiment provides imaging evidence in vivo for EPO treating cerebral ischemia/reperfusion injury.

  2. Erythropoietin reduces apoptosis of brain tissue cells in rats after cerebral ischemia/reperfusion injury: a characteristic analysis using magnetic resonance imaging

    PubMed Central

    Jiang, Chun-juan; Wang, Zhong-juan; Zhao, Yan-jun; Zhang, Zhui-yang; Tao, Jing-jing; Ma, Jian-yong

    2016-01-01

    Some in vitro experiments have shown that erythropoietin (EPO) increases resistance to apoptosis and facilitates neuronal survival following cerebral ischemia. However, results from in vivo studies are rarely reported. Perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) have been applied successfully to distinguish acute cerebral ischemic necrosis and penumbra in living animals; therefore, we hypothesized that PWI and DWI could be used to provide imaging evidence in vivo for the conclusion that EPO could reduce apoptosis in brain areas injured by cerebral ischemia/reperfusion. To validate this hypothesis, we established a rat model of focal cerebral ischemia/reperfusion injury, and treated with intra-cerebroventricular injection of EPO (5,000 U/kg) 20 minutes before injury. Brain tissue in the ischemic injury zone was sampled using MRI-guided localization. The relative area of abnormal tissue, changes in PWI and DWI in the ischemic injury zone, and the number of apoptotic cells based on TdT-mediated dUTP-biotin nick end-labeling (TUNEL) were assessed. Our findings demonstrate that EPO reduces the relative area of abnormally high signal in PWI and DWI, increases cerebral blood volume, and decreases the number of apoptotic cells positive for TUNEL in the area injured by cerebral ischemia/reperfusion. The experiment provides imaging evidence in vivo for EPO treating cerebral ischemia/reperfusion injury. PMID:27857749

  3. Effects of the duration of hyperlipidemia on cerebral lipids, vessels and neurons in rats.

    PubMed

    Yang, Weichun; Shi, He; Zhang, Jianfen; Shen, Ziyi; Zhou, Guangyu; Hu, Minyu

    2017-01-31

    The present study was designed to investigate the effects of hyperlipidemia on the cerebral lipids, vessels and neurons of rats, and to provide experimental evidence for subsequent intervention. One hundred adult SD rats, half of which were male and half of which were female, were randomly divided into five groups on the basis of serum total cholesterol (TC) levels. Four groups were fed a hypercholesterolemic diet (rat chow supplemented with 4% cholesterol, 1% cholic acid and 0.5% thiouracil - this is also called a CCT diet) for periods of 1 week, 2 weeks, 3 weeks and 4 weeks, respectively. A control group was included. The levels of serum lipids, cerebral lipids, free fatty acids (FFA), interleukin-6 (IL-6), interleukin-1 (IL-1), tumor necrosis factor alpha (TNF-α), vascular endothelial growth factor (VEGF), oxidized low density lipoprotein (ox-LDL), A-beta precursor proteins (APP), amyloid beta (Aβ), glial fibrillary acidic protein (GFAP) and tight junction protein Claudin-5 were measured after the experiment. The pathologic changes and apoptosis of the rat brains were evaluated. Compared with the control group, after 1 week of a CCT diet, the levels of serum total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C) and brain triglycerides had increased by 2.40, 1.29 and 1.75 and 0.3 times, respectively. The serum high density lipoprotein cholesterol (HDL-C) had decreased by 0.74 times (P < 0.05) and the expression of IL-1, TNF-α and GFAP in the brains had increased (P < 0.05). In the second week, the expression of FFA and APP in the brains, and the amount of apoptotic neurons, had increased (P < 0.05). In the third week, the levels of VEGF, Ox-LDL and Aβ had increased, and the expression of Claudin-5 had decreased in the brains (P < 0.05). In the fourth week, the levels of TC, LDL-C and the amount of apoptotic neurons had increased (P < 0.05). The correlation analysis showed a positive correlation among

  4. Activation of the calcium-sensing receptor promotes apoptosis by modulating the JNK/p38 MAPK pathway in focal cerebral ischemia-reperfusion in mice

    PubMed Central

    Zhen, Yilan; Ding, Caijuan; Sun, Jiaqiang; Wang, Yanan; Li, Sheng; Dong, Liuyi

    2016-01-01

    Exact mechanism of cerebral ischemic stroke remains unclear. The calcium-sensing receptor (CaSR), a G-protein coupled receptor, has been reported to participate in the pathology of myocardial ischemia-reperfusion (I/R) injury and myocardial hypertrophy. Nevertheless, only a limited number of studies have been conducted to investigate the role of CaSR in cerebral ischemic stroke. This study was to investigate the effect of CaSR activation on cerebral ischemic stroke. Male adult Kunming mice were subjected to 2-h focal cerebral ischemia followed by 22-h reperfusion. Then, the brain was collected, and the expression of CaSR, JNK, p38, Bcl-2, and Bax was detected by Western blot assay. The morphology of neurons in the brain was evaluated by HE staining. Neurological function was scored, and the infarct volume was determined by TTC (triphenyltetrazolium chloride) staining. Results showed that ischemia/reperfusion (I/R) increased CaSR expression and induced neuronal apoptosis in the brain. Gadolinium trichloride (GdCl3), an agonist of CaSR, further deteriorated neurological dysfunction, increased infarct volume, enhanced CaSR expression, and promoted neuronal apoptosis. In addition, GdCl3 unregulated expression of Bax, p-JNK, and p-p38, and down-regulated Bcl-2 expression during I/R, which were attenuated by NPS2390, an inhibitor of CaSR. In conclusion, the CaSR activation promotes apoptosis in focal cerebral I/R in mice, which may be related to the activation of JNK/p38 MAPK signalling pathway. Targeting CaSR may be a novel strategy for the prevention and treatment of cerebral ischemic stroke. PMID:27158378

  5. Sodium influx through cerebral sodium-glucose transporter type 1 exacerbates the development of cerebral ischemic neuronal damage.

    PubMed

    Yamazaki, Yui; Harada, Shinichi; Wada, Tetsuyuki; Hagiwara, Teruki; Yoshida, Shigeru; Tokuyama, Shogo

    2017-03-15

    We recently reported that cerebral sodium-glucose transporter type 1 (SGLT-1) plays a role in exacerbation of cerebral ischemia. However, the mechanism by which cerebral SGLT-1 acts remains unclear. Here we demonstrated that sodium influx through cerebral SGLT-1 exacerbates cerebral ischemic neuronal damage. SGLT-specific sodium ion influx was induced using α-methyl-D-glucopyranoside (α-MG). Intracellular sodium concentrations in primary cortical neurons were estimated using sodium-binding benzofuran isophthalate fluorescence. SGLT-1 knockdown in primary cortical neurons and mice was achieved using SGLT-1 siRNA. The survival rates of primary cultured cortical neurons were assessed using biochemical assays 1 day after treatment. Middle cerebral artery occlusion (MCAO) was used to generate a focal cerebral ischemic model in SGLT-1 knockdown mice. The change in fasting blood glucose levels, infarction development, and behavioral abnormalities were assessed 1 day after MCAO. Treatment with 200mM α-MG induced a continuous increase in the intracellular sodium concentration, and this increase was normalized after α-MG removal. Neuronal SGLT-1 knockdown had no effect on 100µM H2O2-induced neuronal cell death; however, the knockdown prevented the neuronal cell death induced by 17.5mM glucose and the co-treatment of 100µM H2O2/8.75mM glucose. Neuronal SGLT-1 knockdown also suppressed the cell death induced by α-MG alone and the co-treatment of 100µM H2O2/0.01mM α-MG. Our in vivo results showed that the exacerbation of cerebral ischemic neuronal damage induced by the intracerebroventricular administration of 5.0µg α-MG/mouse was ameliorated in cerebral SGLT-1 knockdown mice. Thus, sodium influx through cerebral SGLT-1 may exacerbate cerebral ischemia-induced neuronal damage. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. [Effect of Ruiqi tablet on mitochondrion activities in cerebral cortex neurons of fetal rats].

    PubMed

    Zhou, Peiyun; Ge, Wenjin; Li, Duanwu

    2010-06-01

    To explore the effect of Ruiqi tablet on mitochondrion activities in the cerebral cortex neurons of fetal mice. The cerebral cortex of fetal Wistar rats after 16- 17 gestation days were collected and randomized into Ruiqi tablet group and blank control group after 4-5 days' culture. Laser scanning confocal microscope was adopted to determine the changes in the mitochondrion activities of the primary cultured cerebral cortex neurons of fetal rats after addition of Ruiqi tablet solution. Ruiqi tablet can increase the mitochondrion activities of the cerebral cortex neurons. No significant change in the mitochondrion activities of the cerebral cortex neurons was found in the blank control group. Ruiqi tablet can increase the mitochondrion activities of the neurons and it has certain application prospects in treatment of some neurodegenerative diseases such as Alzheimer's disease, vascular dementia, Parkinson's disease and so on.

  7. Tetramethyl Pyrazine Protects Hippocampal Neurons Against Anoxia/Reoxygenation Injury Through Inhibiting Apoptosis Mediated by JNK/MARK Signal Pathway

    PubMed Central

    Zhong, Ming; Ma, Wuhua; Zhang, Xiong; Wang, Yong; Gao, Xiaoqiu

    2016-01-01

    Background Tetramethyl pyrazine (TMP) is a typical biologically active alkaloid isolated from the Chinese herb Ligusticum walliichi. It has been reported that TMP shows neuroprotective and stroke injury reductive properties in cerebral ischemia/reperfusion (I/R) animal models. In the present study we sought to investigate the effect and potential intervention mechanism of TMP in anoxia/reoxygenation (A/R) rat hippocampal neurons. Material/Methods After being cultured for 7 days, primary hippocampal neurons were randomly assigned into a normal control group (N), a TMP group (C: 0 ug/ml, L: 60 ug/ml, M: 200ug/ml and H: 800 ug/ml), and a JNK inhibitor group (S: SP600125, 10 μmol/L). A hypoxia/reoxygenation model were prepared 1 h after incubation. Hippocampal neurons were incubated in 90% N2 and 10% CO2 for 2 h, and then reoxygenated for 24 h in an incubator with 5%CO2 at the temperature of 37°C. The apoptosis rate, MKK4 and MKK7 mRNA and JNK kinase protein levels (C-fos, c-jun, and P-JNK) of hippocampal neurons were detected. Results The apoptosis rates of hippocampal neurons induced by A/R showed significant reduction after being pre-treated with JNK inhibitor, TMP 60 μg/ml, 200 μg/ml, and 800 μg/ml. The JNK kinase MKK4mRNA and MKK7mRNA levels, as well as the expressions of C-fos, C-jun, and P-JNK protein levels, were also be reduced. Conclusions TMP may produce a protective effect in anoxia/reoxygenation-induced primary hippocampal neuronal injury by inhibiting the apoptosis of the hippocampal neurons; the possible mechanism may be inhibition of the JNK signal pathway. PMID:28009855

  8. Tetramethyl Pyrazine Protects Hippocampal Neurons Against Anoxia/Reoxygenation Injury Through Inhibiting Apoptosis Mediated by JNK/MARK Signal Pathway.

    PubMed

    Zhong, Ming; Ma, Wuhua; Zhang, Xiong; Wang, Yong; Gao, Xiaoqiu

    2016-12-23

    BACKGROUND Tetramethyl pyrazine (TMP) is a typical biologically active alkaloid isolated from the Chinese herb Ligusticum walliichi. It has been reported that TMP shows neuroprotective and stroke injury reductive properties in cerebral ischemia/reperfusion (I/R) animal models. In the present study we sought to investigate the effect and potential intervention mechanism of TMP in anoxia/reoxygenation (A/R) rat hippocampal neurons. MATERIAL AND METHODS After being cultured for 7 days, primary hippocampal neurons were randomly assigned into a normal control group (N), a TMP group (C: 0 ug/ml, L: 60 ug/ml, M: 200ug/ml and H: 800 ug/ml), and a JNK inhibitor group (S: SP600125, 10 μmol/L). A hypoxia/reoxygenation model were prepared 1 h after incubation. Hippocampal neurons were incubated in 90% N2 and 10% CO2 for 2 h, and then reoxygenated for 24 h in an incubator with 5%CO2 at the temperature of 37°C. The apoptosis rate, MKK4 and MKK7 mRNA and JNK kinase protein levels (C-fos, c-jun, and P-JNK) of hippocampal neurons were detected. RESULTS The apoptosis rates of hippocampal neurons induced by A/R showed significant reduction after being pre-treated with JNK inhibitor, TMP 60 µg/ml, 200 µg/ml, and 800 µg/ml. The JNK kinase MKK4mRNA and MKK7mRNA levels, as well as the expressions of C-fos, C-jun, and P-JNK protein levels, were also be reduced. CONCLUSIONS TMP may produce a protective effect in anoxia/reoxygenation-induced primary hippocampal neuronal injury by inhibiting the apoptosis of the hippocampal neurons; the possible mechanism may be inhibition of the JNK signal pathway.

  9. Neuroprotective effects of polydatin against mitochondrial-dependent apoptosis in the rat cerebral cortex following ischemia/reperfusion injury.

    PubMed

    Gao, Youguang; Chen, Ting; Lei, Xianghui; Li, Yunfeng; Dai, Xingui; Cao, Yuanyuan; Ding, Qionglei; Lei, Xiabao; Li, Tao; Lin, Xianzhong

    2016-12-01

    The neuroprotective effect of polydatin (PD) against hemorrhagic shock-induced mitochondrial injury has been described previously, and mitochondrial dysfunction and apoptosis were reportedly involved in ischemic stroke. In the present study the neuroprotective effect of PD in preventing apoptosis was evaluated following induction of focal cerebral ischemia by middle cerebral artery occlusion (MCAO) in rats. PD (30 mg/kg) was administered by caudal vein injection 10 min prior to ischemia/reperfusion (I/R) injury. 24 h following I/R injury, ameliorated modified neurological severity scores (mNSS) and reduced infarct volume were observed in the PD treated group. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and Annexin V/propidium iodide assays demonstrated the anti-apoptotic effect of PD in the ischemic cortex. In addition, PD improved I/R injury‑induced mitochondrial dysfunction, reflected by morphological observations and measurements of mitochondrial membrane potential and intracellular ATP measurement. Western blot analysis revealed an increase in B‑cell lymphoma 2 apoptosis regulator (Bcl-2) expression, and a decrease in Bcl‑2‑associated protein X apoptosis regulator expression in the PD group in comparison with the vehicle treated group. PD treatment also prevented the release of cytochrome c from mitochondria into the cytoplasm, and blunted the activities of caspase‑9 and caspase‑3. Furthermore, PD treatment decreased the levels of reactive oxygen species in neurons isolated from the ischemic cortex. The findings of this study, therefore, suggest that PD has a dual effect, ameliorating both oxidative stress and mitochondria‑dependent apoptosis, making it a promising new therapy for the treatment of ischemic stroke.

  10. Effect of intravascular irradiation of He-Ne laser on cerebral infarction: Hemorrheology and apoptosis

    NASA Astrophysics Data System (ADS)

    Zhu, Jian; Liang, Min-yi; Cao, Hao-cai; Li, Xiao-Yuan; Li, Shao-ming; Li, Shun-hao; Li, Wen-qi; Zhang, Jin-hong; Liu, Lei; Lai, Jian-hong

    2005-07-01

    Objective: To explore the efficacy of He-Ne laser intravascular irradiation on infarction and hemorrheology. To observe the effects of intravascular low level He-Ne laser irradiation (ILLLI) of blood on cell proliferation, apoptosis and chromosome in lymphocyte from cerebral infarction Methods: Seventy cases with cerebral infarction were randomly divided into groups control group (35 cases) treated only with common drugs and therapeutic group (35 cases) treated besides common drugs also by He-Ne laser intravascular irradiation. Their hemorrheology index and treatment results were observed and compared. The blood lymphocytes of cerebral infarction were cultured before and after treatment. After that, the mitosis index (MI), cell kinetics index (CKI), sister-chromatid exchanges (SCE) frequencies and apoptosis were determined. Results The therapeutic group was better than the control one. The effective rate in the therapeutic group was 88.6%, in the control one was 65.7%. The viscosity and fibrinogen, etc were better than that in the control group with significant difference (P<0.01). The lymphocyte proliferation index was significantly two increased than the control one (P>0.05) in cerebral infarction patients after treatment; The CKI of lymphocytes had no obvious difference among groups (P>0.05) SCE frequencies of lymphocytes had no statistic significance between control group and ILLLI on (P>0.05). It showed the apoptosis rate of lymphocytes in cerebral infarction patients after ILLLI treatment increased significantly compared with the control group, (P<0.001). There was a significant difference of apoptosis rate of lymphocytes in cerebral infarction patients than the control (P<0.001). Conclusions: During the He-Ne laser intravascular irradiation of the cerebral infarction, the low level He-Ne by ILLLI can increase the proliferation of lymphocytes, and can induce lymphocytes to apoptosis, but has no mutagenicity of cells.

  11. Electroacupuncture Attenuates Cerebral Ischemia and Reperfusion Injury in Middle Cerebral Artery Occlusion of Rat via Modulation of Apoptosis, Inflammation, Oxidative Stress, and Excitotoxicity

    PubMed Central

    Shen, Mei-hong; Zhang, Chun-bing; Zhang, Jia-hui; Li, Peng-fei

    2016-01-01

    Electroacupuncture (EA) has several properties such as antioxidant, antiapoptosis, and anti-inflammatory properties. The current study was to investigate the effects of EA on the prevention and treatment of cerebral ischemia-reperfusion (I/R) injury and to elucidate possible molecular mechanisms. Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) for 2 h followed by reperfusion for 24 h. EA stimulation was applied to both Baihui and Dazhui acupoints for 30 min in each rat per day for 5 successive days before MCAO (pretreatment) or when the reperfusion was initiated (treatment). Neurologic deficit scores, infarction volumes, brain water content, and neuronal apoptosis were evaluated. The expressions of related inflammatory cytokines, apoptotic molecules, antioxidant systems, and excitotoxic receptors in the brain were also investigated. Results showed that both EA pretreatment and treatment significantly reduced infarct volumes, decreased brain water content, and alleviated neuronal injury in MCAO rats. Notably, EA exerts neuroprotection against I/R injury through improving neurological function, attenuating the inflammation cytokines, upregulating antioxidant systems, and reducing the excitotoxicity. This study provides a better understanding of the molecular mechanism underlying the traditional use of EA. PMID:27123035

  12. 3-N-butylphthalide improves neuronal morphology after chronic cerebral ischemia

    PubMed Central

    Zhao, Wanhong; Luo, Chao; Wang, Jue; Gong, Jian; Li, Bin; Gong, Yingxia; Wang, Jun; Wang, Hanqin

    2014-01-01

    3-N-butylphthalide is an effective drug for acute ischemic stroke. However, its effects on chronic cerebral ischemia-induced neuronal injury remain poorly understood. Therefore, this study ligated bilateral carotid arteries in 15-month-old rats to simulate chronic cerebral ischemia in aged humans. Aged rats were then intragastrically administered 3-n-butylphthalide. 3-N-butylphthalide administration improved the neuronal morphology in the cerebral cortex and hippocampus of rats with chronic cerebral ischemia, increased choline acetyltransferase activity, and decreased malondialdehyde and amyloid beta levels, and greatly improved cognitive function. These findings suggest that 3-n-butylphthalide alleviates oxidative stress caused by chronic cerebral ischemia, improves cholinergic function, and inhibits amyloid beta accumulation, thereby improving cerebral neuronal injury and cognitive deficits. PMID:25206879

  13. MicroRNA-378 Alleviates Cerebral Ischemic Injury by Negatively Regulating Apoptosis Executioner Caspase-3

    PubMed Central

    Zhang, Nan; Zhong, Jie; Han, Song; Li, Yun; Yin, Yanling; Li, Junfa

    2016-01-01

    miRNAs have been linked to many human diseases, including ischemic stroke, and are being pursued as clinical diagnostics and therapeutic targets. Among the aberrantly expressed miRNAs in our previous report using large-scale microarray screening, the downregulation of miR-378 in the peri-infarct region of middle cerebral artery occluded (MCAO) mice can be reversed by hypoxic preconditioning (HPC). In this study, the role of miR-378 in the ischemic injury was further explored. We found that miR-378 levels significantly decreased in N2A cells following oxygen-glucose deprivation (OGD) treatment. Overexpression of miR-378 significantly enhanced cell viability, decreased TUNEL-positive cells and the immunoreactivity of cleaved-caspase-3. Conversely, downregulation of miR-378 aggravated OGD-induced apoptosis and ischemic injury. By using bioinformatic algorithms, we discovered that miR-378 may directly bind to the predicted 3′-untranslated region (UTR) of Caspase-3 gene. The protein level of caspase-3 increased significantly upon OGD treatment, and can be downregulated by pri-miR-378 transfection. The luciferase reporter assay confirmed the binding of miR-378 to the 3′-UTR of Caspase-3 mRNA and repressed its translation. In addition, miR-378 agomir decreased cleaved-caspase-3 ratio, reduced infarct volume and neural cell death induced by MCAO. Furthermore, caspase-3 knockdown could reverse anti-miR-378 mediated neuronal injury. Taken together, our data demonstrated that miR-378 attenuated ischemic injury by negatively regulating the apoptosis executioner, caspase-3, providing a potential therapeutic target for ischemic stroke. PMID:27598143

  14. Nuclear factor kappa B modulates apoptosis in the brain endothelial cells and intravascular leukocytes of fatal cerebral malaria.

    PubMed

    Punsawad, Chuchard; Maneerat, Yaowapa; Chaisri, Urai; Nantavisai, Kwannan; Viriyavejakul, Parnpen

    2013-07-26

    Cerebral malaria (CM) caused by Plasmodium falciparum is known to be associated with the sequestration of parasitized red blood cells (PRBCs) in the microvasculature and the release of soluble cytokines. In addition, the involvement of signaling molecules has gained wide interest in the pathogenesis of CM. An important signaling factor, nuclear factor kappa B (NF-κB) is known to regulate apoptosis. This work aimed to study the expression of NF-κB p65 and its correlation with apoptosis in the brain of fatal CM. The expression of NF-κB p65 and cleaved caspase-3 in the brain of fatal P. falciparum malaria cases was investigated by immunohistochemistry. Histopathological features were analysed together with the correlations of NF-κB p65 and cleaved caspase-3 expression. NF-κB p65 activation and cleaved caspase-3 expression were significantly increased in the neurons, glial cells, vascular endothelial cells (ECs) and intravascular leukocytes of the brain in fatal CM, compared with the control brain (p < 0.001) and non-cerebral malaria (NCM) (p = 0.034). The percentage of neurons that expressed nuclear NF-κB p65 showed a positive correlation with the total score of histopathological changes (rs = 0.678; p = 0.045). Significant positive correlations were established between vascular ECs NF-κB index and ECs apoptotic index (rs = 0.717; p = 0.030) and between intravascular leukocytes NF-κB index and leukocytes apoptotic index (rs = 0.696; p = 0.037) in fatal CM. This study documented that NF-κB p65 is one of the signaling factors that modulates apoptosis in the brain ECs and intravascular leukocytes of fatal CM.

  15. Nuclear factor kappa B modulates apoptosis in the brain endothelial cells and intravascular leukocytes of fatal cerebral malaria

    PubMed Central

    2013-01-01

    Background Cerebral malaria (CM) caused by Plasmodium falciparum is known to be associated with the sequestration of parasitized red blood cells (PRBCs) in the microvasculature and the release of soluble cytokines. In addition, the involvement of signaling molecules has gained wide interest in the pathogenesis of CM. An important signaling factor, nuclear factor kappa B (NF-κB) is known to regulate apoptosis. This work aimed to study the expression of NF-κB p65 and its correlation with apoptosis in the brain of fatal CM. Methods The expression of NF-κB p65 and cleaved caspase-3 in the brain of fatal P. falciparum malaria cases was investigated by immunohistochemistry. Histopathological features were analysed together with the correlations of NF-κB p65 and cleaved caspase-3 expression. Results NF-κB p65 activation and cleaved caspase-3 expression were significantly increased in the neurons, glial cells, vascular endothelial cells (ECs) and intravascular leukocytes of the brain in fatal CM, compared with the control brain (p < 0.001) and non-cerebral malaria (NCM) (p = 0.034). The percentage of neurons that expressed nuclear NF-κB p65 showed a positive correlation with the total score of histopathological changes (rs = 0.678; p = 0.045). Significant positive correlations were established between vascular ECs NF-κB index and ECs apoptotic index (rs = 0.717; p = 0.030) and between intravascular leukocytes NF-κB index and leukocytes apoptotic index (rs = 0.696; p = 0.037) in fatal CM. Conclusions This study documented that NF-κB p65 is one of the signaling factors that modulates apoptosis in the brain ECs and intravascular leukocytes of fatal CM. PMID:23890318

  16. Neuroprotective effects of a standardized extract of Diospyros kaki leaves on MCAO transient focal cerebral ischemic rats and cultured neurons injured by glutamate or hypoxia.

    PubMed

    Bei, Weijian; Peng, Wenlie; Zang, Linquan; Xie, Zhiyong; Hu, Dehui; Xu, Anlong

    2007-06-01

    Naoxinqing (NXQ, a standardized extract of Diospyros kaki leaves) is a patented and approved drug of Traditional Chinese Medicine (TCM) used for the treatment of apoplexy syndrome for years in China, but its underlying mechanism remains to be further elucidated. The present study investigates the effects of NXQ against focal ischemia/reperfusion injury induced by middle cerebral artery occlusion (MCAO) in rats and against glutamate-induced cell injury of hippocampal neurons as well as against hypoxia injury of cortical neurons. Oral administrations of NXQ at 20, 40, 80 mg/kg/day for 7 days (3 days before MCAO and 4 days after MCAO) significantly reduced the lesion of the insulted brain hemisphere and improved the neurological behavior of the rats. In primary rat hippocampal neuron cultures, treatment with NXQ at 5 - 20 microg mL concentration protects the neurons against glutamate-induced excitotoxic death in a dose-dependent manner. In primary rat cerebral cortical neuron cultures, pretreatment with 5 - 100 microg/mL NXQ also attenuates hypoxia-reoxygen induced neuron death and apoptosis in a dose-dependent manner. These results suggest that NXQ significantly protects the rats from MCAO ischemic injury in vivo and the hippocampal neurons from glutamate-induced excitotoxic injury as well as cortical neurons from hypoxia injury in vitro by synergistic mechanisms involving its antioxidative effects. NXQ:Naoxinqing CNS:central nervous system MCAO:middle cerebral artery occlusion I/R:ischemia and reperfusion.

  17. Effects and Mechanism of Action of Inducible Nitric Oxide Synthase on Apoptosis in a Rat Model of Cerebral Ischemia-Reperfusion Injury.

    PubMed

    Zheng, Li; Ding, Junli; Wang, Jianwei; Zhou, Changman; Zhang, Weiguang

    2016-02-01

    Inducible nitric oxide synthase (iNOS) is a key enzyme in regulating nitric oxide (NO) synthesis under stress, and NO has varying ability to regulate apoptosis. The aim of this study was to investigate the effects and possible mechanism of action of iNOS on neuronal apoptosis in a rat model of cerebral focal ischemia and reperfusion injury in rats treated with S-methylisothiourea sulfate (SMT), a high-selective inhibitor of iNOS. Seventy-two male Sprague-Dawley (SD) rats were randomly divided into three groups: the sham, middle cerebral artery occlusion (MCAO) + vehicle, and MCAO + SMT groups. Neurobehavioral deficits, infarct zone size, and cortical neuron morphology were evaluated through the modified Garcia scores, 2,3,5-triphenyltetrazolium chloride (TTC), and Nissl staining, respectively. Brain tissues and serum samples were collected at 72 hr post-reperfusion for immunohistochemical analysis, Western blotting, Terminal deoxynucleotidyl transferase-mediated dUTP-biotin Nick End Labeling assay (TUNEL) staining, and enzyme assays. The study found that inhibition of iNOS significantly attenuated the severity of the pathological changes observed as a result of ischemia-reperfusion injury: SMT reduced NO content as well as total nitric oxide synthase (tNOS) and iNOS activities in both ischemic cerebral hemisphere and serum, improved neurobehavioral scores, reduced mortality, reduced the infarct volume ratio, attenuated morphological changes in cortical neurons, decreased the rate of apoptosis (TUNEL and caspase-3-positive), and increased phospho (p)-AKT expression in ischemic penumbra. These results suggested that inhibition of iNOS might reduce the severity of ischemia-reperfusion injury by inhibiting neuronal apoptosis via maintaining p-AKT activity.

  18. Induction of apoptosis by thrombin in the cultured neurons of dorsal motor nucleus of the vagus.

    PubMed

    Wu, X; Zhang, W; Li, J-Y; Chai, B-X; Peng, J; Wang, H; Mulholland, M W

    2011-03-01

    A previous study demonstrated the presence of protease-activated receptor (PAR) 1 and 2 in the dorsal motor nucleus of vagus (DMV). The aim of this study is to characterize the effect of thrombin on the apoptosis of DMV neurons. The dorsal motor nucleus of vagus neurons were isolated from neonatal rat brainstems using micro-dissection and enzymatic digestion and cultured. Apoptosis of DMV neurons were examined in cultured neurons. Apoptotic neuron was examined by TUNEL and ELISA. Data were analyzed using anova and Student's t-test. Exposure of cultured DMV neurons to thrombin (0.1 to 10 U mL(-1)) for 24 h significantly increased apoptosis. Pretreatment of DMV neurons with hirudin attenuated the apoptotic effect of thrombin. Similar induction of apoptosis was observed for the PAR1 receptor agonist SFLLR, but not for the PAR3 agonist TFRGAP, nor for the PAR4 agonist YAPGKF. Protease-activated receptors 1 receptor antagonist Mpr(Cha) abolished the apoptotic effect of thrombin, while YPGKF, a specific antagonist for PAR4, demonstrated no effect. After administration of thrombin, phosphorylation of JNK and P38 occurred as early as 15 min, and remained elevated for up to 45 min. Pretreatment of DMV neurons with SP600125, a specific inhibitor for JNK, or SB203580, a specific inhibitor for P38, significantly inhibited apoptosis induced by thrombin. Thrombin induces apoptosis in DMV neurons through a mechanism involving the JNK and P38 signaling pathways. © 2010 Blackwell Publishing Ltd.

  19. Long-lasting neuronal loss following experimental focal cerebral ischemia is not affected by combined administration of tissue plasminogen activator and hyperbaric oxygen.

    PubMed

    Hobohm, Carsten; Laignel, Félix; Kacza, Johannes; Küppers-Tiedt, Lea; Heindl, Marita; Schneider, Dietmar; Grosche, Jens; Härtig, Wolfgang; Michalski, Dominik

    2011-10-12

    Acute focal cerebral ischemia and consecutive energy failure are accompanied by neuronal death in regions with impaired cerebral blood flow. Several translational attempts of potential neuroprotective agents have failed, hence extended perspectives are required regarding the regional differences of neuronal impairment and glial involvement by using clinically relevant stroke models. This study aimed on neuronal loss following experimental focal cerebral ischemia, considering tissue plasminogen activator (tPA) as established treatment in stroke and hyperbaric oxygenation (HBO) as potential neuroprotective co-treatment. Wistar rats were subjected to embolic middle cerebral artery occlusion and underwent either treatment with tPA only, combined tPA+HBO, or no treatment. Neuronal impairment was assessed by Neuronal Nuclei (NeuN) staining in 4 ischemia-related areas and at 4 different time points after stroke induction (24hours, 7, 14 and 28 days). Additionally, spatial relationships between neuronal loss and gliosis were revealed by triple fluorescence staining of neurons, astrocytes and microglia, comparing the ipsi- and contra-lesional hemisphere. Analyzing the ischemic injury in general, a shell-like distribution of neuronal damage was observed, starting in the ischemic core and diminishing over the general ischemic area to the ischemic border zone and the primary non-affected area. This pattern remained detectable up to 4weeks after ischemia induction. Surprisingly, tPA and tPA+HBO did not markedly affect the post-ischemic course of neuronal impairment. Further studies are needed to investigate the effects of treatment with tPA or potential neuroprotective agents on neuronal integrity, with emphasis on the separation of intact neurons from those undergoing apoptosis or necrosis. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. (-)-Deprenyl reduces neuronal apoptosis and facilitates neuronal outgrowth by altering protein synthesis without inhibiting monoamine oxidase.

    PubMed

    Tatton, W G; Wadia, J S; Ju, W Y; Chalmers-Redman, R M; Tatton, N A

    1996-01-01

    (-)-Deprenyl stereospecifically reduces neuronal death even after neurons have sustained seemingly lethal damage at concentrations too small to cause monoamine oxidase-B (MAO-B) inhibition. (-)-Deprenyl can also influence the process growth of some glial and neuronal populations and can reduce the concentrations of oxidative radicals in damaged cells at concentrations too small to inhibit MAO. In accord with the earlier work of others, we showed that (-)-deprenyl alters the expression of a number mRNAs or proteins in nerve and glial cells and that the alterations in gene expression/protein synthesis are the result of a selective action on transcription. The alterations in gene expression/protein synthesis are accompanied by a decrease in DNA fragmentation characteristic of apoptosis and the death of responsive cells. The onco-proteins Bcl-2 and Bax and the scavenger proteins Cu/Zn superoxide dismutase (SOD1) and Mn superoxide dismutase (SOD2) are among the 40-50 proteins whose synthesis is altered by (-)-deprenyl. Since mitochondrial ATP production depends on mitochondrial membrane potential (MMP) and mitochondrial failure has been shown to be one of the earliest events in apoptosis, we used confocal laser imaging techniques in living cells to show that the transcriptional changes induced by (-)-deprenyl are accompanied by a maintenance of mitochondrial membrane potential, a decrease in intramitochondrial calcium and a decrease in cytoplasmic oxidative radical levels. We therefore propose that (-)-deprenyl acts on gene expression to maintain mitochondrial function and to decrease cytoplasmic oxidative radical levels and thereby to reduce apoptosis. An understanding of the molecular steps by which (-)-deprenyl selectively alters transcription may contribute to the development of new therapies for neurodegenerative diseases.

  1. Oxidative DNA Damage Mediated by Intranuclear MMP Activity Is Associated with Neuronal Apoptosis in Ischemic Stroke.

    PubMed

    Kimura-Ohba, Shihoko; Yang, Yi

    2016-01-01

    Evidence of the pathological roles of matrix metalloproteinases (MMPs) in various neurological disorders has made them attractive therapeutic targets. MMPs disrupt the blood-brain barrier and cause neuronal death and neuroinflammation in acute cerebral ischemia and are critical for angiogenesis during recovery. However, some challenges have to be overcome before MMPs can be further validated as drug targets in stroke injury. Identifying in vivo substrates of MMPs should greatly improve our understanding of the mechanisms of ischemic injury and is critical for providing more precise drug targets. Recent works have uncovered nontraditional roles for MMPs in the cytosol and nucleus. These have shed light on intracellular targets and biological actions of MMPs, adding additional layers of complexity for therapeutic MMP inhibition. In this review, we discussed the recent advances made in understanding nuclear location of MMPs, their regulation of intranuclear sorting, and their intranuclear proteolytic activity and substrates. In particular, we highlighted the roles of intranuclear MMPs in oxidative DNA damage, neuronal apoptosis, and neuroinflammation at an early stage of stroke insult. These novel data point to new putative MMP-mediated intranuclear actions in stroke-induced pathological processes and may lead to novel approaches to treatment of stroke and other neurological diseases.

  2. Aβ induces PUMA activation: a new mechanism for Aβ-mediated neuronal apoptosis.

    PubMed

    Feng, Jie; Meng, Chengbo; Xing, Da

    2015-02-01

    p53 upregulated modulator of apoptosis (PUMA) is a promising tumor therapy target because it elicits apoptosis and profound sensitivity to radiation and chemotherapy. However, inhibition of PUMA may be beneficial for curbing excessive apoptosis associated with neurodegenerative disorders. Alzheimer's disease (AD) is a representative neurodegenerative disease in which amyloid-β (Aβ) deposition causes neurotoxicity. The regulation of PUMA during Aβ-induced neuronal apoptosis remains poorly understood. Here, we reported that PUMA expression was significantly increased in the hippocampus of transgenic mice models of AD and hippocampal neurons in response to Aβ. PUMA knockdown protected the neurons against Aβ-induced apoptosis. Furthermore, besides p53, PUMA transactivation was also regulated by forkhead box O3a through p53-independent manner following Aβ treatment. Notably, PUMA contributed to neuronal apoptosis through competitive binding of apoptosis repressor with caspase recruitment domain to activate caspase-8 that cleaved Bid into tBid to accelerate Bax mitochondrial translocation, revealing a novel pathway of Bax activation by PUMA to mediate Aβ-induced neuronal apoptosis. Together, we demonstrated that PUMA activation involved in Aβ-induced apoptosis, representing a drug target to antagonize AD progression.

  3. Cerebral cortical neurons with activity linked to central neurogenic spontaneous and evoked elevations in cerebral blood flow

    NASA Technical Reports Server (NTRS)

    Golanov, E. V.; Reis, D. J.

    1996-01-01

    We recorded neurons in rat cerebral cortex with activity relating to the neurogenic elevations in regional cerebral blood flow (rCBF) coupled to stereotyped bursts of EEG activity, burst-cerebrovascular wave complexes, appearing spontaneously or evoked by electrical stimulation of rostral ventrolateral medulla (RVL) or fastigial nucleus (FN). Of 333 spontaneously active neurons only 15 (5%), in layers 5-6, consistently (P < 0.05, chi-square) increased their activity during the earliest potential of the complex, approximately 1.3 s before the rise of rCBF, and during the minutes-long elevation of rCBF elicited by 10 s of stimulation of RVL or FN. The results indicate the presence of a small population of neurons in deep cortical laminae whose activity correlates with neurogenic elevations of rCBF. These neurons may function to transduce afferent neuronal signals into vasodilation.

  4. Cerebral cortical neurons with activity linked to central neurogenic spontaneous and evoked elevations in cerebral blood flow

    NASA Technical Reports Server (NTRS)

    Golanov, E. V.; Reis, D. J.

    1996-01-01

    We recorded neurons in rat cerebral cortex with activity relating to the neurogenic elevations in regional cerebral blood flow (rCBF) coupled to stereotyped bursts of EEG activity, burst-cerebrovascular wave complexes, appearing spontaneously or evoked by electrical stimulation of rostral ventrolateral medulla (RVL) or fastigial nucleus (FN). Of 333 spontaneously active neurons only 15 (5%), in layers 5-6, consistently (P < 0.05, chi-square) increased their activity during the earliest potential of the complex, approximately 1.3 s before the rise of rCBF, and during the minutes-long elevation of rCBF elicited by 10 s of stimulation of RVL or FN. The results indicate the presence of a small population of neurons in deep cortical laminae whose activity correlates with neurogenic elevations of rCBF. These neurons may function to transduce afferent neuronal signals into vasodilation.

  5. Maturation-dependent modulation of apoptosis in cultured cerebellar granule neurons by cytokines and neurotrophins.

    PubMed

    de Luca, A; Weller, M; Frei, K; Fontana, A

    1996-09-01

    Immature cerebellar granule neurons die by apoptosis within 1 week in vitro unless maintained in depolarizing (high) concentrations of potassium (25 mM K+). Neurons allowed to survive and differentiate in high K+ medium for several days in vitro are still induced to undergo apoptosis when switched back to physiological (low) concentrations of K+ (5 mM). Here we have investigated the effects of various cytokines and growth factors in these two well-defined paradigms of neuronal apoptosis. Tumour necrosis factor-alpha, leukaemia inhibitory factor, ciliary neurotrophic factor, interleukin-10 and interleukin-13 delayed apoptosis and prolonged survival of cerebellar granule neurons maintained in low K+ medium. The effect observed required continuous exposure of the cultures to the cytokines and appeared not to involve modulation of Bcl-2 protein expression. Brain-derived neurotrophic factor accelerated neuronal death in low K+ medium. In contrast, when apoptosis of the neurons was precipitated by switching mature high K+ neurons to low K+ medium, neither tumour necrosis factor-alpha, leukaemia inhibitory factor, ciliary neurotrophic factor, interleukin-10 nor interleukin-13 prevented apoptosis. When testing the cytokines and growth factors for their capacity to alter N-methyl-D-aspartate receptor-mediated excitotoxicity of differentiated cerebellar granule neurons, no significant effect was observed. These data appear to define a maturation-dependent modulation of cerebellar granule cell survival by cytokines and neurotrophic factors that are expressed in a developmental pattern in the mammalian brain.

  6. Primary cerebral and cerebellar astrocytes display differential sensitivity to extracellular sodium with significant effects on apoptosis.

    PubMed

    Takeda, Tomohiko; Makinodan, Manabu; Fukami, Shin-ichi; Toritsuka, Michihiro; Ikawa, Daisuke; Yamashita, Yasunori; Kishimoto, Toshifumi

    2014-06-01

    Central pontine myelinolysis is one of the idiopathic or iatrogenic brain dysfunction, and the most common cause is excessively rapid correction of chronic hyponatraemia. While myelin disruption is the main pathology, as the diagnostic name indicates, a previous study has reported that astrocyte death precedes the destruction of the myelin sheath after the rapid correction of chronic low Na(+) levels, and interestingly, certain brain regions (cerebral cortex, hippocampus, etc.) are specifically damaged but not cerebellum. Here, using primary astrocyte cultures derived from rat cerebral cortex and cerebellum, we examined how extracellular Na(+) alterations affect astrocyte death and whether the response is different between the two populations of astrocytes. Twice the amount of extracellular [Na(+) ] and voltage-gated Na(+) channel opening induced substantial apoptosis in both populations of astrocytes, while, in contrast, one half [Na(+) ] prevented apoptosis in cerebellar astrocytes, in which the Na(+) -Ca(2+) exchanger, NCX2, was highly expressed but not in cerebral astrocytes. Strikingly, the rapid correction of chronic one half [Na(+) ] exposure significantly increased apoptosis in cerebellar astrocytes but not in cerebral astrocytes. These results indicate that extracellular [Na(+) ] affects astrocyte apoptosis, and the response to alterations in [Na(+) ] is dependent on the brain region from which the astrocyte is derived.

  7. Antenatal supplementation of taurine for protection of fetal rat brain with intrauterine growth restriction from injury by reducing neuronal apoptosis.

    PubMed

    Liu, Jing; Liu, Li; Wang, Xiao-Feng; Teng, Hui-Yun; Yang, Na

    2012-10-01

    This study aimed to investigate whether antenatal taurine can reduce neuronal apoptosis in fetal rat brains with intrauterine growth restriction (IUGR) and its possible mechanisms. A total of 15 pregnant rats were randomly divided into the following three groups: control, IUGR, and IUGR+ antenatal taurine supplements. Neuronal apoptosis was detected using transferase-mediated dUTP biotin nick end-labeling (TUNEL); the expression of Bcl-2, Bax, and caspase-3 mRNA and proteins was detected by reverse transcription-polymerase chain reaction and immunohistochemistry. In IUGR groups, the results were as follows: (1) the expression of Bcl-2 decreased whereas the expression of Bax increased, accordingly, the ratio of Bcl-2/Bax decreased, (2) the expression of caspase-3 increased significantly, and (3) apoptotic neuron counts in IUGR groups was significantly increased compared with controls. In taurine supplement groups, the results were as follows: (1) the expression of Bcl-2 increased whereas the expression of Bax decreased, accordingly, the ratio of Bcl-2/Bax increased, (2) the expression of caspase-3 in fetal rat cerebral cortex tissues decreased significantly, and (3) the number of apoptotic neurons was significantly decreased compared with IUGR groups. In addition, the changes in the expression of Bcl-2, Bax, and caspase-3 mRNA and protein were correlated. So we concluded that antenatal supplementation of taurine may reduce neuronal apoptosis in IUGR fetal rats via up-regulating the ratio of Bcl-2/Bax and down-regulating the expression of caspase-3. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  8. Hrk/DP5 contributes to the apoptosis of select neuronal populations but is dispensable for haematopoietic cell apoptosis.

    PubMed

    Coultas, Leigh; Terzano, Susanna; Thomas, Tim; Voss, Anne; Reid, Kate; Stanley, Edouard G; Scott, Clare L; Bouillet, Philippe; Bartlett, Perry; Ham, Jonathan; Adams, Jerry M; Strasser, Andreas

    2007-06-15

    The pro-apoptotic BH3-only members of the Bcl2 family, crucial initiators of cell death, are activated by a diverse array of developmental cues or experimentally applied stress stimuli. We have investigated, through gene targeting in mice, the biological roles for the BH3-only family member HRK (also known as DP5) in apoptosis regulation. Hrk gene expression was found to be restricted to cells and tissues of the central and peripheral nervous systems. Sensory neurons from mice lacking Hrk were less sensitive to apoptosis induced by nerve growth factor (NGF) withdrawal, consistent with the induction of Hrk following NGF deprivation. By contrast, cerebellar granule neurons that upregulate Hrk upon transfer to low-K+ medium underwent apoptosis normally under these conditions in the absence of Hrk. Furthermore, loss of Hrk was not sufficient to rescue the neuronal degeneration in lurcher mutant mice. Despite previous reports, no evidence was found for Hrk expression or induction in growth-factor-dependent haematopoietic cell lines following withdrawal of their requisite cytokine, and haematopoietic progenitors lacking HRK died normally in response to cytokine deprivation. These results demonstrate that HRK contributes to apoptosis signalling elicited by trophic factor withdrawal in certain neuronal populations but is dispensable for apoptosis of haematopoietic cells.

  9. Hrk/DP5 contributes to the apoptosis of select neuronal populations but is dispensable for haematopoietic cell apoptosis

    PubMed Central

    Coultas, Leigh; Terzano, Susanna; Thomas, Tim; Voss, Anne; Reid, Kate; Stanley, Edouard G.; Scott, Clare L.; Bouillet, Philippe; Bartlett, Perry; Ham, Jonathan; Adams, Jerry M.; Strasser, Andreas

    2009-01-01

    Summary The pro-apoptotic BH3-only members of the Bcl2 family, crucial initiators of cell death, are activated by a diverse array of developmental cues or experimentally applied stress stimuli. We have investigated, through gene targeting in mice, the biological roles for the BH3-only family member HRK (also known as DP5) in apoptosis regulation. Hrk gene expression was found to be restricted to cells and tissues of the central and peripheral nervous systems. Sensory neurons from mice lacking Hrk were less sensitive to apoptosis induced by nerve growth factor (NGF) withdrawal, consistent with the induction of Hrk following NGF deprivation. By contrast, cerebellar granule neurons that upregulate Hrk upon transfer to low-K+ medium underwent apoptosis normally under these conditions in the absence of Hrk. Furthermore, loss of Hrk was not sufficient to rescue the neuronal degeneration in lurcher mutant mice. Despite previous reports, no evidence was found for Hrk expression or induction in growth-factor-dependent haematopoietic cell lines following withdrawal of their requisite cytokine, and haematopoietic progenitors lacking HRK died normally in response to cytokine deprivation. These results demonstrate that HRK contributes to apoptosis signalling elicited by trophic factor withdrawal in certain neuronal populations but is dispensable for apoptosis of haematopoietic cells. PMID:17535852

  10. Beclin-1-mediated autophagy protects spinal cord neurons against mechanical injury-induced apoptosis.

    PubMed

    Wang, Zhen-Yu; Lin, Jian-Hua; Muharram, Akram; Liu, Wen-Ge

    2014-06-01

    Apoptosis has been widely reported to be involved in the pathogenesis associated with spinal cord injury (SCI). Recently, autophagy has also been implicated in various neuronal damage models. However, the role of autophagy in SCI is still controversial and its interrelationship with apoptosis remains unclear. Here, we used an in vitro SCI model to observe a time-dependent induction of autophagy and apoptosis. Mechanical injury induced autophagy markers such as LC3 lipidation, LC3II/LC3I conversion, and Beclin-1 expression. Injured neurons showed decreased cell viability and increased apoptosis. To elucidate the effect of autophagy on apoptosis, the mechanically-injured neurons were treated with the mTOR inhibitor rapamycin and 3-methyl adenine (3-MA), which are known to regulate autophagy positively and negatively, respectively. Rapamycin-treated neurons showed the highest level of cell viability and lowest level of apoptosis among the injured neurons and those treated with 3-MA showed the reciprocal effect. Notably, rapamycin-treated neurons exhibited slightly reduced Bax expression and significantly increased Bcl-2 expression. Furthermore, by plasmid transfection, we showed that Beclin-1-overexpressing neuronal cells responded to mechanical injury with greater LC3II/LC3I conversion and cell viability, lower levels of apoptosis, higher Bcl-2 expression, and unaltered Bax expression as compared to vector control cells. Beclin-1-knockdown neurons showed almost the opposite effects. Taken together, our results suggest that autophagy may serve as a protection against apoptosis in mechanically-injured spinal cord neurons. Targeting mTOR and/or enhancing Beclin-1 expression might be alternative therapeutic strategies for SCI.

  11. The pesticide rotenone induces caspase-3-mediated apoptosis in ventral mesencephalic dopaminergic neurons.

    PubMed

    Ahmadi, Ferogh A; Linseman, Daniel A; Grammatopoulos, Tom N; Jones, Susan M; Bouchard, Ron J; Freed, Curt R; Heidenreich, Kim A; Zawada, W Michael

    2003-11-01

    In vivo, the pesticide rotenone induces degeneration of dopamine neurons and parkinsonian-like pathology in adult rats. In the current study, we utilized primary ventral mesencephalic (VM) cultures from E15 rats as an in vitro model to examine the mechanism underlying rotenone-induced death of dopamine neurons. After 11 h of exposure to 30 nm rotenone, the number of dopamine neurons identified by tyrosine hydroxylase (TH) immunostaining declined rapidly with only 23% of the neurons surviving. By contrast, 73% of total cells survived rotenone treatment, indicating that TH+ neurons are more sensitive to rotenone. Examination of the role of apoptosis in TH+ neuron death, revealed that 10 and 30 nm rotenone significantly increased the number of apoptotic TH+ neurons from 7% under control conditions to 38 and 55%, respectively. The increase in apoptotic TH+ neurons correlated with an increase in immunoreactivity for active caspase-3 in TH+ neurons. The caspase-3 inhibitor, DEVD, rescued a significant number of TH+ neurons from rotenone-induced death. Furthermore, this protective effect lasted for at least 32 h post-rotenone and DEVD exposure, indicating lasting neuroprotection achieved with an intervention prior to the death commitment point. Our results show for the first time in primary dopamine neurons that, at low nanomolar concentrations, rotenone induces caspase-3-mediated apoptosis. Understanding the mechanism of rotenone-induced apoptosis in dopamine neurons may contribute to the development of new neuroprotective strategies against Parkinson's disease.

  12. Effects of ApoE on intracellular calcium levels and apoptosis of neurons after mechanical injury.

    PubMed

    Jiang, L; Zhong, J; Dou, X; Cheng, C; Huang, Z; Sun, X

    2015-08-20

    The current study aimed to explore the effects of apolipoprotein e (ApoE) on intracellular calcium ([Ca(2+)]i) and apoptosis of neurons after mechanical injury in vitro. A neuron mechanical injury model was established after primary neurons obtained from APOE knockout and wild-type (WT) mice, and four experimental groups were generated: Group-ApoE4, Group-ApoE3, Group-ApoE(-) and Group-WT. Recombinant ApoE4 and ApoE3 were added to Group-ApoE4 and Group-ApoE3 respectively, and Group-ApoE(-) and Group-WT were control groups. Intracellular calcium was labeled by fluo-3/AM and examined using laser scanning confocal microscope and flow cytometry, and the apoptosis of neurons was also evaluated. The intracellular calcium levels and apoptosis rates of mice neurons were significantly higher in Group-ApoE4 than in Group-ApoE3 and Group-WT after mechanical injury. However, without mechanical injury on neurons, no significant differences in intracellular calcium levels and apoptosis rates were found among all four experimental groups. The effects of ApoE4 on intracellular calcium levels and apoptosis rates of injured neurons were partly decreased by EGTA treatment. Compared with ApoE3-treatment and WT neurons, ApoE4 caused higher intracellular calcium levels and apoptosis rates of neurons after mechanical injury. This suggested APOE polymorphisms may affect neuron apoptosis after mechanical injury through different influences on intracellular calcium levels. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Peroxynitrite induces apoptosis in canine cerebral vascular muscle cells: possible relation to neurodegenerative diseases and strokes.

    PubMed

    Li, Jianfeng; Su, Jialin; Li, Wenyan; Liu, Weimin; Altura, Bella T; Altura, Burton M

    2003-10-30

    Considerable evidence is accumulating to suggest that in vivo formation of free radicals in the brain, such as peroxynitrite (ONOO-), and programmed cell death (i.e. apoptosis) play important roles in neurodegeneration and stroke. However, it is not known whether ONOO- can induce apoptosis in cerebral vascular smooth muscle cells (CVSMCs). The present study was designed to determine whether or not canine CVSMCs undergo apoptosis following treatment with ONOO-. Direct exposure of canine CVSMCs to ONOO- induced apoptosis in a concentration-dependent manner, as confirmed by means of fluorescence staining, TdT-mediated dUTP nick-end labeling and comet assays. Peroxynitrite treatment resulted in an elevation of [Ca2+]i in the CVSMCs. Peroxynitrite-induced apoptosis may thus be brought about by activation of Ca2+-dependent endonucleases. Although the precise mechanisms by which peroxynitrite induces apoptosis need to be further investigated, the present findings could be used to suggest that ONOO- formation in the brain may play important roles in neurodegenerative processes and strokes via detrimental actions on cerebral microvessels and blood flow.

  14. Switching modes in corticogenesis: mechanisms of neuronal subtype transitions and integration in the cerebral cortex

    PubMed Central

    Toma, Kenichi; Hanashima, Carina

    2015-01-01

    Information processing in the cerebral cortex requires the activation of diverse neurons across layers and columns, which are established through the coordinated production of distinct neuronal subtypes and their placement along the three-dimensional axis. Over recent years, our knowledge of the regulatory mechanisms of the specification and integration of neuronal subtypes in the cerebral cortex has progressed rapidly. In this review, we address how the unique cytoarchitecture of the neocortex is established from a limited number of progenitors featuring neuronal identity transitions during development. We further illuminate the molecular mechanisms of the subtype-specific integration of these neurons into the cerebral cortex along the radial and tangential axis, and we discuss these key features to exemplify how neocortical circuit formation accomplishes economical connectivity while maintaining plasticity and evolvability to adapt to environmental changes. PMID:26321900

  15. Genetic and Molecular Approaches to Study Neuronal Migration in the Developing Cerebral Cortex.

    PubMed

    Dudok, Jacobus J; Leonards, Pim E G; Wijnholds, Jan

    2017-05-05

    The migration of neuronal cells in the developing cerebral cortex is essential for proper development of the brain and brain networks. Disturbances in this process, due to genetic abnormalities or exogenous factors, leads to aberrant brain formation, brain network formation, and brain function. In the last decade, there has been extensive research in the field of neuronal migration. In this review, we describe different methods and approaches to assess and study neuronal migration in the developing cerebral cortex. First, we discuss several genetic methods, techniques and genetic models that have been used to study neuronal migration in the developing cortex. Second, we describe several molecular approaches to study aberrant neuronal migration in the cortex which can be used to elucidate the underlying mechanisms of neuronal migration. Finally, we describe model systems to investigate and assess the potential toxicity effect of prenatal exposure to environmental chemicals on proper brain formation and neuronal migration.

  16. Genetic and Molecular Approaches to Study Neuronal Migration in the Developing Cerebral Cortex

    PubMed Central

    Dudok, Jacobus J.; Leonards, Pim E. G.; Wijnholds, Jan

    2017-01-01

    The migration of neuronal cells in the developing cerebral cortex is essential for proper development of the brain and brain networks. Disturbances in this process, due to genetic abnormalities or exogenous factors, leads to aberrant brain formation, brain network formation, and brain function. In the last decade, there has been extensive research in the field of neuronal migration. In this review, we describe different methods and approaches to assess and study neuronal migration in the developing cerebral cortex. First, we discuss several genetic methods, techniques and genetic models that have been used to study neuronal migration in the developing cortex. Second, we describe several molecular approaches to study aberrant neuronal migration in the cortex which can be used to elucidate the underlying mechanisms of neuronal migration. Finally, we describe model systems to investigate and assess the potential toxicity effect of prenatal exposure to environmental chemicals on proper brain formation and neuronal migration. PMID:28475113

  17. The role of myocardin-related transcription factor-A in Aβ25-35 induced neuron apoptosis and synapse injury.

    PubMed

    Zhang, Ying; Pan, Hong-Yan; Hu, Xia-Min; Cao, Xiao-Lu; Wang, Jun; Min, Zhen-Li; Xu, Shi-Qiang; Xiao, Wan; Yuan, Qiong; Li, Na; Cheng, Jing; Zhao, Shu-Qi; Hong, Xing

    2016-10-01

    Myocardin-related transcription factor-A (MRTF-A) highly expressed in brain has been demonstrated to promote neuronal survival via regulating the transcription of related target genes as a powerful co-activator of serum response factor (SRF). However, the role of MRTF-A in Alzheimer's disease (AD) is still unclear. Here, we showed that MRTF-A was significantly downregulated in cortex of the Aβ25-35-induced AD rats, which played a key role in Aβ25-35 induced cerebral neuronal degeneration in vitro. Bilateral intracerebroventricular injection of Aβ25-35 caused significantly MRTF-A expression decline in cortex of rats, along with significant neuron apoptosis and plasticity damage. In vitro, transfection of MRTF-A into primary cultured cortical neurons prevented Aβ25-35 induced neuronal apoptosis and synapses injury. And luciferase reporter assay determined that MRTF-A could bind to and enhance the transactivity of the Mcl-1 (Myeloid cell leukemia-1) and Arc (activity-regulated cytoskeletal-associated protein) promoters by activating the key CArG box element. These data demonstrated that the decreasing of endogenous MRTF-A expression might contribute to the development of AD, whereas the upregulation MRTF-A in neurons could effectively reduce Aβ25-35 induced synapse injury and cell apoptosis. And the underlying mechanism might be partially due to MRTF-A-mediated the transcription and expression of Mcl-1 and Arc by triggering the CArG box.

  18. Pretreatment with scutellaria baicalensis stem-leaf total flavonoid protects against cerebral ischemia/reperfusion injury in hippocampal neurons

    PubMed Central

    Kong, Xiangyu; Kong, Wei; Miao, Guangxin; Zhao, Shumin; Chen, Meng; Zheng, Xiaoying; Bai, Jiangtao

    2014-01-01

    Previous experimental studies have shown that cerebral infarction can be effectively reduced following treatment with scutellaria baicalensis stem-leaf total flavonoid (SSTF). However, the mechanism of action of SSTF as a preventive drug to treat cerebral infarction remains unclear. In this study, Sprague-Dawley rats were pretreated with 50, 100, 200 mg/kg SSTF via intragastric administration for 1 week prior to the establishment of focal cerebral ischemia/reperfusion injury. The results showed that pretreatment with SSTF effectively improved neurological function, reduced brain water content and the permeability of blood vessels, ameliorated ischemia-induced morphology changes in hippocampal microvessels, down-regulated Fas and FasL protein expression, elevated the activity of superoxide dismutase and glutathione peroxidase, and decreased malondialdehyde content. In contrast to low-dose SSTF pretreatment, the above changes were most obvious after pretreatment with moderate- and high-doses of SSTF. Experimental findings indicate that SSTF pretreatment can exert protective effects on the brain against cerebral ischemia/reperfusion injury. The underlying mechanisms may involve reducing brain water content, increasing microvascular recanalization, inhibiting the apoptosis of hippocampal neurons, and attenuating free radical damage. PMID:25657723

  19. Autophagy: a double-edged sword for neuronal survival after cerebral ischemia

    PubMed Central

    Chen, Wenqi; Sun, Yinyi; Liu, Kangyong; Sun, Xiaojiang

    2014-01-01

    Evidence suggests that autophagy may be a new therapeutic target for stroke, but whether activation of autophagy increases or decreases the rate of neuronal death is still under debate. This review summarizes the potential role and possible signaling pathway of autophagy in neuronal survival after cerebral ischemia and proposes that autophagy has dual effects. PMID:25206784

  20. Myosin IIA-related Actomyosin Contractility Mediates Oxidative Stress-induced Neuronal Apoptosis.

    PubMed

    Wang, Yan; Xu, Yingqiong; Liu, Qian; Zhang, Yuanyuan; Gao, Zhen; Yin, Mingzhu; Jiang, Nan; Cao, Guosheng; Yu, Boyang; Cao, Zhengyu; Kou, Junping

    2017-01-01

    Oxidative stress-induced neuronal apoptosis plays an important role in the progression of central nervous system (CNS) diseases. In our study, when neuronal cells were exposed to hydrogen peroxide (H2O2), an exogenous oxidant, cell apoptosis was observed with typical morphological changes including membrane blebbing, neurite retraction and cell contraction. The actomyosin system is considered to be responsible for the morphological changes, but how exactly it regulates oxidative stress-induced neuronal apoptosis and the distinctive functions of different myosin II isoforms remain unclear. We demonstrate that myosin IIA was required for neuronal contraction, while myosin IIB was required for neuronal outgrowth in normal conditions. During H2O2-induced neuronal apoptosis, myosin IIA, rather than IIB, interacted with actin filaments to generate contractile forces that lead to morphological changes. Moreover, myosin IIA knockout using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein-9 nuclease (CRISPR/Cas9) reduced H2O2-induced neuronal apoptosis and the associated morphological changes. We further demonstrate that caspase-3/Rho-associated kinase 1 (ROCK1) dependent phosphorylation of myosin light chain (MLC) was required for the formation of the myosin IIA-actin complex. Meanwhile, either inhibition of myosin II ATPase with blebbistatin or knockdown of myosin IIA with siRNA reversely attenuated caspase-3 activation, suggesting a positive feedback loop during oxidative stress-induced apoptosis. Based on our observation, myosin IIA-actin complex contributes to actomyosin contractility and is associated with the positive feedback loop of caspase-3/ROCK1/MLC pathway. This study unravels the biochemical and mechanistic mechanisms during oxidative stress-induced neuronal apoptosis and may be applicable for the development of therapies for CNS diseases.

  1. Myosin IIA-related Actomyosin Contractility Mediates Oxidative Stress-induced Neuronal Apoptosis

    PubMed Central

    Wang, Yan; Xu, Yingqiong; Liu, Qian; Zhang, Yuanyuan; Gao, Zhen; Yin, Mingzhu; Jiang, Nan; Cao, Guosheng; Yu, Boyang; Cao, Zhengyu; Kou, Junping

    2017-01-01

    Oxidative stress-induced neuronal apoptosis plays an important role in the progression of central nervous system (CNS) diseases. In our study, when neuronal cells were exposed to hydrogen peroxide (H2O2), an exogenous oxidant, cell apoptosis was observed with typical morphological changes including membrane blebbing, neurite retraction and cell contraction. The actomyosin system is considered to be responsible for the morphological changes, but how exactly it regulates oxidative stress-induced neuronal apoptosis and the distinctive functions of different myosin II isoforms remain unclear. We demonstrate that myosin IIA was required for neuronal contraction, while myosin IIB was required for neuronal outgrowth in normal conditions. During H2O2-induced neuronal apoptosis, myosin IIA, rather than IIB, interacted with actin filaments to generate contractile forces that lead to morphological changes. Moreover, myosin IIA knockout using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein-9 nuclease (CRISPR/Cas9) reduced H2O2-induced neuronal apoptosis and the associated morphological changes. We further demonstrate that caspase-3/Rho-associated kinase 1 (ROCK1) dependent phosphorylation of myosin light chain (MLC) was required for the formation of the myosin IIA-actin complex. Meanwhile, either inhibition of myosin II ATPase with blebbistatin or knockdown of myosin IIA with siRNA reversely attenuated caspase-3 activation, suggesting a positive feedback loop during oxidative stress-induced apoptosis. Based on our observation, myosin IIA-actin complex contributes to actomyosin contractility and is associated with the positive feedback loop of caspase-3/ROCK1/MLC pathway. This study unravels the biochemical and mechanistic mechanisms during oxidative stress-induced neuronal apoptosis and may be applicable for the development of therapies for CNS diseases. PMID:28352215

  2. Human Immunodeficiency Virus Type 1 Vpr Induces Apoptosis in Human Neuronal Cells

    PubMed Central

    Patel, Charvi A.; Mukhtar, Muhammad; Pomerantz, Roger J.

    2000-01-01

    Human immunodeficiency virus type 1 (HIV-1) infection of the central nervous system (CNS) causes AIDS dementia complex (ADC) in certain infected individuals. Recent studies have suggested that patients with ADC have an increased incidence of neuronal apoptosis leading to neuronal dropout. Of note, a higher level of the HIV-1 accessory protein Vpr has been detected in the cerebrospinal fluid of AIDS patients with neurological disorders. Moreover, extracellular Vpr has been shown to form ion channels, leading to cell death of cultured rat hippocampal neurons. Based on these previous findings, we first investigated the apoptotic effects of the HIV-1 Vpr protein on the human neuronal precursor NT2 cell line at a range of concentrations. These studies demonstrated that apoptosis induced by both Vpr and the envelope glycoprotein, gp120, occurred in a dose-dependent manner compared to protein treatment with HIV-1 integrase, maltose binding protein (MBP), and MBP-Vpr in the undifferentiated NT2 cells. For mature, differentiated neurons, apoptosis was also induced in a dose-dependent manner by both Vpr and gp120 at concentrations ranging from 1 to 100 ng/ml, as demonstrated by both the terminal deoxynucleotidyltransferase (Tdt)-mediated dUTP-biotin nick end labeling and Annexin V assays for apoptotic cell death. In order to clarify the intracellular pathways and molecular mechanisms involved in Vpr- and gp120-induced apoptosis in the NT2 cell line and differentiated mature human neurons, we then examined the cellular lysates for caspase-8 activity in these studies. Vpr and gp120 treatments exhibited a potent increase in activation of caspase-8 in both mature neurons and undifferentiated NT2 cells. This suggests that Vpr may be exerting selective cytotoxicity in a neuronal precursor cell line and in mature human neurons through the activation of caspase-8. These data represent a characterization of Vpr-induced apoptosis in human neuronal cells, and suggest that extracellular

  3. Apoptosis in subicular neurons: A comparison between suicide and Addison's disease

    PubMed Central

    Printha, K.; Hulathduwa, S. R.; Samarasinghe, K.; Suh, Y. H.; De Silva, K. R. D.

    2009-01-01

    Background: Stress and depression shows possible links to neuronal death in hippocampus. Subiculum plays a prominent role in limbic stress integration and direct effect of corticosteroids on subicular neurons needs to be defined to assess its subsequent impact on hippocampal plasticity. Aim: This study was intended to assess apoptosis in subicular neurons of a young depressed suicide victim, where presumably stress induced excess of corticosteroids and a case of young Addison's disease with low level of corticosteroids. Materials and Method: Both bilateral adrenal glands (Addison's) and subiculum (both cases) were initially stained with hematoxylin and eosin; subicular neurons of both cases were examined for the degree of apoptosis using ‘ApopTag Kit’. Apoptotic cell counts were expressed as average number of labeled cells/mm2 and the results were analysed statistically using a non-parametric Mann–Whitney U test. Result: Apoptotic neurons were detected in the subicular region of both suicide and Addison victims, and it is statistically significant in both right and left between the cases (P < 0.05). In suicide victim, the neuronal apoptosis is considerably significant between the two hemispheres (P < 0.05), in contrast to Addison disease where the number of neuronal cell death between right and left was statistically insignificant (P > 0.05). Conclusion: The present study confirms the vulnerability of the subicular neurons to apoptosis, possibly due to corticosteroids in both ends of spectrum. PMID:20048453

  4. Neuropeptide Y protects cerebral cortical neurons by regulating microglial immune function

    PubMed Central

    Li, Qijun; Dong, Changzheng; Li, Wenling; Bu, Wei; Wu, Jiang; Zhao, Wenqing

    2014-01-01

    Neuropeptide Y has been shown to inhibit the immunological activity of reactive microglia in the rat cerebral cortex, to reduce N-methyl-D-aspartate current (INMDA) in cortical neurons, and protect neurons. In this study, after primary cultured microglia from the cerebral cortex of rats were treated with lipopolysaccharide, interleukin-1β and tumor necrosis factor-α levels in the cell culture medium increased, and mRNA expression of these cytokines also increased. After primary cultured cortical neurons were incubated with the lipopolysaccharide-treated microglial conditioned medium, peak INMDA in neurons increased. These effects of lipopolysaccharide were suppressed by neuropeptide Y. After addition of the neuropeptide Y Y1 receptor antagonist BIBP3226, the effects of neuropeptide Y completely disappeared. These results suggest that neuropeptide Y prevents excessive production of interleukin-1β and tumor necrosis factor-α by inhibiting microglial reactivity. This reduces INMDA in rat cortical neurons, preventing excitotoxicity, thereby protecting neurons. PMID:25206918

  5. Expression of gonadotropin-releasing hormone receptor in cerebral cortical neurons of embryos and adult rats.

    PubMed

    Quintanar, J Luis; Salinas, Eva; González, Rodolfo

    2007-01-03

    Mammalian gonadotropin-releasing hormone (GnRH) was initially isolated from hypothalamus and its receptor from anterior pituitary, although extrapituitary GnRH receptors have been reported. The aim of the present study was to investigate whether GnRH receptor and its mRNA are expressed in cerebral cortical neurons of rat embryos and adult rats using immunohistochemical and reverse transcriptase polymerase chain reaction (RT-PCR) techniques. The immunohistochemistry and RT-PCR analysis showed expression of GnRH receptor and presence of its mRNA, in both cerebral cortical neurons of rat embryos and cerebral cortical tissues of adult rats. Additional experiments showed a decrease in the receptor mRNA expression when cultured neurons of rat embryos were treated with GnRH. It is possible that the presence of GnRH receptors in cortical neurons of rat may be involved in other physiological roles such as neurohormone or neuromodulator.

  6. Mecamylamine prevents neuronal apoptosis induced by glutamate and low potassium via differential anticholinergic-independent mechanisms.

    PubMed

    Fu, Hongjun; Dou, Juan; Li, Wenming; Luo, Jialie; Li, Kenny C; Lam, Colin S C; Lee, Nelson T K; Li, Mingtao; Han, Yifan

    2008-03-01

    Neuronal loss via apoptosis caused by various stimuli may be the fundamental mechanism underlying chronic and acute neurodegenerative diseases. A drug inhibiting neuronal apoptosis may lead to a practical treatment for these diseases. In this study, treatment with mecamylamine, a classical antagonist of nicotinic acetylcholine receptors (nAChRs), prevented neuronal apoptosis induced by 75 microM glutamate and by low potassium (LK) in cerebellar granule neurons (CGNs) with EC(50)s of 35 and 293 microM, respectively. Two other antagonists of nAChRs, dihydro-beta-erythroidine and tubocurarine, failed to inhibit these two kinds of apoptosis. Mecamylamine inhibited the NMDA (30 microM)-evoked current and competed with [(3)H]MK-801. Furthermore, two inhibiters of the c-Jun N-terminal kinase (JNK) pathway prevented LK-induced apoptosis. Mecamylamine reversed the phosphorylation levels of JNK and c-Jun as well as the expression of c-Jun caused by LK in a Western blot assay. In addition, the JNK/c-Jun pathway was not involved in glutamate-induced cell death of CGNs. Our results suggest that mecamylamine prevents glutamate-induced apoptosis by blocking NMDA receptors at the MK-801 site and LK-induced apoptosis by inhibiting the activation of the JNK/c-Jun pathway.

  7. Radial glia and somal translocation of radial neurons in the developing cerebral cortex.

    PubMed

    Nadarajah, Bagirathy

    2003-07-01

    A series of recent studies have demonstrated that radial glia are neural precursors in the developing cerebral cortex. These studies have further implied that these cells are the sole precursor constituents of the dorsal forebrain ventricular zone that generate the projection neurons of the cortex. In view of these new findings, this review discusses radial neurons, a progeny of cortical neurons that are generated by radial glia and adopt somal translocation as the mode of migration.

  8. The neuroprotective action of dexmedetomidine on apoptosis, calcium entry and oxidative stress in cerebral ischemia-induced rats: Contribution of TRPM2 and TRPV1 channels

    PubMed Central

    Akpınar, Hatice; Nazıroğlu, Mustafa; Övey, İshak Suat; Çiğ, Bilal; Akpınar, Orhan

    2016-01-01

    Dexmedetomidine (DEX) may act as an antioxidant through regulation of TRPM2 and TRPV1 channel activations in the neurons by reducing cerebral ischemia-induced oxidative stress and apoptosis. The neuroprotective roles of DEX were tested on cerebral ischemia (ISC) in the cultures of rat primary hippocampal and DRG neurons. Fifty-six rats were divided into five groups. A placebo was given to control, sham control, and ISC groups, respectively. In the third group, ISC was induced. The DEX and ISC+DEX groups received intraperitoneal DEX (40 μg/kg) 3, 24, and 48 hours after ISC induction. DEX effectively reversed capsaicin and cumene hydroperoxide/ADP-ribose-induced TRPV1 and TRPM2 densities and cytosolic calcium ion accumulation in the neurons, respectively. In addition, DEX completely reduced ISC-induced oxidative toxicity and apoptosis through intracellular reactive oxygen species production and depolarization of mitochondrial membrane. The DEX and ISC+DEX treatments also decreased the expression levels of caspase 3, caspase 9, and poly (ADP-ribose) polymerase in the hippocampus and DRG. In conclusion, the current results are the first to demonstrate the molecular level effects of DEX on TRPM2 and TRPV1 activation. Therefore, DEX can have remarkable neuroprotective impairment effects in the hippocampus and DRG of ISC-induced rats. PMID:27872485

  9. The neuroprotective action of dexmedetomidine on apoptosis, calcium entry and oxidative stress in cerebral ischemia-induced rats: Contribution of TRPM2 and TRPV1 channels.

    PubMed

    Akpınar, Hatice; Nazıroğlu, Mustafa; Övey, İshak Suat; Çiğ, Bilal; Akpınar, Orhan

    2016-11-22

    Dexmedetomidine (DEX) may act as an antioxidant through regulation of TRPM2 and TRPV1 channel activations in the neurons by reducing cerebral ischemia-induced oxidative stress and apoptosis. The neuroprotective roles of DEX were tested on cerebral ischemia (ISC) in the cultures of rat primary hippocampal and DRG neurons. Fifty-six rats were divided into five groups. A placebo was given to control, sham control, and ISC groups, respectively. In the third group, ISC was induced. The DEX and ISC+DEX groups received intraperitoneal DEX (40 μg/kg) 3, 24, and 48 hours after ISC induction. DEX effectively reversed capsaicin and cumene hydroperoxide/ADP-ribose-induced TRPV1 and TRPM2 densities and cytosolic calcium ion accumulation in the neurons, respectively. In addition, DEX completely reduced ISC-induced oxidative toxicity and apoptosis through intracellular reactive oxygen species production and depolarization of mitochondrial membrane. The DEX and ISC+DEX treatments also decreased the expression levels of caspase 3, caspase 9, and poly (ADP-ribose) polymerase in the hippocampus and DRG. In conclusion, the current results are the first to demonstrate the molecular level effects of DEX on TRPM2 and TRPV1 activation. Therefore, DEX can have remarkable neuroprotective impairment effects in the hippocampus and DRG of ISC-induced rats.

  10. Electroacupuncture Ameliorates Cerebral Ischemia-Reperfusion Injury by Regulation of Autophagy and Apoptosis

    PubMed Central

    Shu, Shi; Li, Chun-Ming; You, Yan-Li; Qian, Xiao-Lu

    2016-01-01

    Background. The therapeutic mechanisms of cerebral ischemia treatment by acupuncture are yet not well addressed. Objective. We investigated the effects of electroacupuncture (EA) at GV26 observing the expression of autophagy-related proteins Beclin-1 and LC3B and proportion of apoptotic cells and Bcl-2 positive cells in MCAO/R model rats. Methods. Sprague-Dawley (SD) male rats were randomly assigned to 7 groups: model groups (M6h, M24h, and M72h), EA treatment groups (T6h, T24h, and T72h), and sham operation group (S). Neurological deficit and cerebral infarction volume were measured to assess the improvement effect, while the expression of Beclin-1 and LC3B and proportion of Tunel-positive and Bcl-2 positive cells were examined to explore EA effect on autophagy and apoptosis. Results. EA significantly decreased neurological deficit scores and the volume of cerebral infarction. Beclin-1 was significantly decreased in T24h, while LC3B-II/LC3B-I ratio markedly reduced in 6th hour. EA groups markedly reduced the number of Tunel positive cells, especially in T24h. Meanwhile, the number of Bcl-2 positive cells obviously increased after EA treatment, especially in T6h and T24h. Conclusions. The alleviation of inadequate autophagy and apoptosis may be a key mechanism involved in the reflex regulation of EA at GV26 to treat cerebral ischemia. PMID:27800003

  11. Cesium chloride protects cerebellar granule neurons from apoptosis induced by low potassium.

    PubMed

    Zhong, Jin; Yao, Weiguo; Lee, Weihua

    2007-10-01

    Neuronal apoptosis plays a critical role in the pathogenesis of neurodegenerative disorders, and neuroprotective agents targeting apoptotic signaling could have therapeutic use. Here we report that cesium chloride, an alternative medicine in treating radiological poison and cancer, has neuroprotective actions. Serum and potassium deprivation induced cerebellar granule neurons to undergo apoptosis, which correlated with the activation of caspase-3. Cesium prevented both the activation of caspase-3 and neuronal apoptosis in a dose-dependent manner. Cesium at 8 mM increased the survival of neurons from 45 +/- 3% to 91 +/- 5% of control. Cesium's neuroprotection was not mediated by PI3/Akt or MAPK signaling pathways, since it was unable to activate either Akt or MAPK by phosphorylation. In addition, specific inhibitors of PI3 kinase and MAP kinase did not block cesium's neuroprotective effects. On the other hand, cesium inactivated GSK3beta by phosphorylation of serine-9 and GSK3beta-specific inhibitor SB415286 prevented neuronal apoptosis. These data indicate that cesium's neuroprotection is likely via inactivating GSK3beta. Furthermore, cesium also prevented H(2)O(2)-induced neuronal death (increased the survival of neurons from 72 +/- 4% to 89 +/- 3% of control). Given its relative safety and good penetration of the brain blood barrier, our findings support the potential therapeutic use of cesium in neurodegenerative diseases.

  12. Studies on Neuronal Apoptosis Following Soman Exposure in the Rat

    DTIC Science & Technology

    2005-10-01

    apoptotic events (caspase-3 activation, high molecular weight DNA fragmentation and Comet assay analysis) occurring out to 48 h following Soman exposure...Comet assay analysis showed significantly increased apoptosis and DNA fragmentation at 24 and 48 h post-exposure. Apoptosis was maximal in the thalamus at

  13. Dopamine selectively sensitizes dopaminergic neurons to rotenone-induced apoptosis.

    PubMed

    Ahmadi, Ferogh A; Grammatopoulos, Tom N; Poczobutt, Andy M; Jones, Susan M; Snell, Laurence D; Das, Mita; Zawada, W Michael

    2008-05-01

    Among various types of neurons affected in Parkinson's disease, dopamine (DA) neurons of the substantia nigra undergo the most pronounced degeneration. Products of DA oxidation and consequent cellular damage have been hypothesized to contribute to neuronal death. To examine whether elevated intracellular DA will selectively predispose the dopaminergic subpopulation of nigral neurons to damage by an oxidative insult, we first cultured rat primary mesencephalic cells in the presence of rotenone to elevate reactive oxygen species. Although MAP2(+) neurons were more sensitive to rotenone-induced toxicity than type 1 astrocytes, rotenone affected equally both DA (TH(+)) neurons and MAP2(+) neurons. In contrast, when intracellular DA concentration was elevated, DA neurons became selectively sensitized to rotenone. Raising intracellular DA levels in primary DA neurons resulted in dopaminergic neuron death in the presence of subtoxic concentrations of rotenone. Furthermore, mitochondrial superoxide dismutase mimetic, manganese (III) meso-tetrakis (4-benzoic acid) porphyrin, blocked activation of caspase-3, and consequent cell death. Our results demonstrate that an inhibitor of mitochondrial complex I and increased cytosolic DA may cooperatively lead to conditions of elevated oxidative stress and thereby promote selective demise of dopaminergic neurons.

  14. Distribution of neurons in functional areas of the mouse cerebral cortex reveals quantitatively different cortical zones.

    PubMed

    Herculano-Houzel, Suzana; Watson, Charles; Paxinos, George

    2013-01-01

    How are neurons distributed along the cortical surface and across functional areas? Here we use the isotropic fractionator (Herculano-Houzel and Lent, 2005) to analyze the distribution of neurons across the entire isocortex of the mouse, divided into 18 functional areas defined anatomically. We find that the number of neurons underneath a surface area (the N/A ratio) varies 4.5-fold across functional areas and neuronal density varies 3.2-fold. The face area of S1 contains the most neurons, followed by motor cortex and the primary visual cortex. Remarkably, while the distribution of neurons across functional areas does not accompany the distribution of surface area, it mirrors closely the distribution of cortical volumes-with the exception of the visual areas, which hold more neurons than expected for their volume. Across the non-visual cortex, the volume of individual functional areas is a shared linear function of their number of neurons, while in the visual areas, neuronal densities are much higher than in all other areas. In contrast, the 18 functional areas cluster into three different zones according to the relationship between the N/A ratio and cortical thickness and neuronal density: these three clusters can be called visual, sensory, and, possibly, associative. These findings are remarkably similar to those in the human cerebral cortex (Ribeiro et al., 2013) and suggest that, like the human cerebral cortex, the mouse cerebral cortex comprises two zones that differ in how neurons form the cortical volume, and three zones that differ in how neurons are distributed underneath the cortical surface, possibly in relation to local differences in connectivity through the white matter. Our results suggest that beyond the developmental divide into visual and non-visual cortex, functional areas initially share a common distribution of neurons along the parenchyma that become delimited into functional areas according to the pattern of connectivity established later.

  15. Reversible recovery of neuronal structures depends on the degree of neuronal damage after global cerebral ischemia in mice.

    PubMed

    Zhu, Lirui; Wang, Lei; Ju, Furong; Khan, Akbar; Cheng, Xiaofeng; Zhang, Shengxiang

    2017-03-01

    It has been observed by in vivo imaging that damaged neuronal structures can be reversibly restored after ischemic insults with the application of timely therapeutic interventions. However, what degree of neuronal damage can be restored and the time frame for reversible recovery of neuronal structures remain unclear. Here, transcranial two-photon imaging, histological staining and electron microscopy were used to investigate the reversible recovery of neuronal structures from dendrites to soma after different durations of global cerebral ischemia in mice. Intravital imaging revealed that the damage to dendritic structures was reversible when ischemia time was <1h, but they became difficult to restore after >3h of ischemia. Data from fixed YFP brain slice and Golgi staining indicated that the damage of dendritic structures progressively extended to deeper dendritic shafts with the extension of ischemia time. Furthermore, longer duration of ischemia caused an increasing number of degenerating neurons. Importantly, significant chromatin margination and karyopyknosis of neuron were observed after 6h of ischemia. These data suggested that neuronal structures could be reversibly restored when ischemia time was <1h, but irreversible and progressive damage to neurons occurred with longer duration of ischemia. Consistently, behavioral performance of post-ischemic animals experienced an ischemia time-dependent recovery. Taken together, our data suggested that recovery of neuronal structures following ischemia was dependent on the duration of ischemia, and prevention of neuronal loss is a key target for therapeutic interventions in ischemic stroke.

  16. A viral vector expressing hypoxia-inducible factor 1 alpha inhibits hippocampal neuronal apoptosis

    PubMed Central

    Chai, Xiqing; Kong, Weina; Liu, Lingyun; Yu, Wenguo; Zhang, Zhenqing; Sun, Yimin

    2014-01-01

    Hypoxia-inducible factor 1 (HIF-1) attenuates amyloid-beta protein neurotoxicity and decreases apoptosis induced by oxidative stress or hypoxia in cortical neurons. In this study, we constructed a recombinant adeno-associated virus (rAAV) vector expressing the human HIF-1α gene (rAAV-HIF-1α), and tested the assumption that rAAV-HIF-1α represses hippocampal neuronal apoptosis induced by amyloid-beta protein. Our results confirmed that rAAV-HIF-1α significantly reduces apoptosis induced by amyloid-beta protein in primary cultured hippocampal neurons. Direct intracerebral rAAV-HIF-1α administration also induced robust and prolonged HIF-1α production in rat hippocampus. Single rAAV-HIF-1α administration resulted in decreased apoptosis of hippocampal neurons in an Alzheimer's disease rat model established by intracerebroventricular injection of aggregated amyloid-beta protein (25–35). Our in vitro and in vivo findings demonstrate that HIF-1 has potential for attenuating hippocampal neuronal apoptosis induced by amyloid-beta protein, and provides experimental support for treatment of neurodegenerative diseases using gene therapy. PMID:25206774

  17. LINGO-1 receptor promotes neuronal apoptosis by inhibiting WNK3 kinase activity.

    PubMed

    Zhang, Zhaohuan; Xu, Xiaohui; Xiang, Zhenghua; Yu, Zhongwang; Feng, Jifeng; He, Cheng

    2013-04-26

    LINGO-1 is a functional component of the Nogo receptor 1 · p75(NTR) · LINGO-1 and Nogo receptor 1 · TAJ (TNFRSF19/TROY)·LINGO-1 signaling complexes. It has recently been shown that LINGO-1 antagonists significantly improve neuronal survival after neural injury. However, the mechanism by which LINGO-1 signaling influences susceptibility to apoptosis remains unknown. In an effort to better understand how LINGO-1 regulates these signaling pathways, we used an established model of serum deprivation (SD) to induce neuronal apoptosis. We demonstrate that treatment either with a construct containing the intracellular domain of LINGO-1 or with Nogo66, a LINGO-1 receptor complex agonist, resulted in an enhanced rate of apoptosis in primary cultured cortical neurons under SD. Reducing the expression levels of the serine/threonine kinase WNK3 using shRNA or inhibiting its kinase activity had similar effects on the survival of serum-deprived neurons. Consistent with these observations, we found that LINGO-1 and WNK3 co-localized and co-precipitated in cultured cortical neurons and brain tissue. Significantly, this co-association was enhanced by Nogo66 treatment. Binding of WNK3 to the intracellular domain of LINGO-1 led to a reduction in WNK3 kinase activity, as did Nogo66 stimulation. Moreover, in vitro and in vivo evidence indicates that endogenous WNK3 suppresses SD-induced neuronal apoptosis in a kinase-dependent manner, as the expression of either a WNK3 RNAi construct or a kinase-dead N-terminal fragment of WNK3 led to increased apoptosis. Taken together, our results show that LINGO-1 potentiates neuronal apoptosis, likely by inhibiting WNK3 kinase activity.

  18. Effect of Ca2EDTA on Zinc Mediated Inflammation and Neuronal Apoptosis in Hippocampus of an In Vivo Mouse Model of Hypobaric Hypoxia

    PubMed Central

    Malairaman, Udayabanu; Dandapani, Kumaran; Katyal, Anju

    2014-01-01

    Background Calcium overload has been implicated as a critical event in glutamate excitotoxicity associated neurodegeneration. Recently, zinc accumulation and its neurotoxic role similar to calcium has been proposed. Earlier, we reported that free chelatable zinc released during hypobaric hypoxia mediates neuronal damage and memory impairment. The molecular mechanism behind hypobaric hypoxia mediated neuronal damage is obscure. The role of free zinc in such neuropathological condition has not been elucidated. In the present study, we investigated the underlying role of free chelatable zinc in hypobaric hypoxia-induced neuronal inflammation and apoptosis resulting in hippocampal damage. Methods Adult male Balb/c mice were exposed to hypobaric hypoxia and treated with saline or Ca2EDTA (1.25 mM/kg i.p) daily for four days. The effects of Ca2EDTA on apoptosis (caspases activity and DNA fragmentation), pro-inflammatory markers (iNOS, TNF-α and COX-2), NADPH oxidase activity, poly(ADP ribose) polymerase (PARP) activity and expressions of Bax, Bcl-2, HIF-1α, metallothionein-3, ZnT-1 and ZIP-6 were examined in the hippocampal region of brain. Results Hypobaric hypoxia resulted in increased expression of metallothionein-3 and zinc transporters (ZnT-1 and ZIP-6). Hypobaric hypoxia elicited an oxidative stress and inflammatory response characterized by elevated NADPH oxidase activity and up-regulation of iNOS, COX-2 and TNF-α. Furthermore, hypobaric hypoxia induced HIF-1α protein expression, PARP activation and apoptosis in the hippocampus. Administration of Ca2EDTA significantly attenuated the hypobaric hypoxia induced oxidative stress, inflammation and apoptosis in the hippocampus. Conclusion We propose that hypobaric hypoxia/reperfusion instigates free chelatable zinc imbalance in brain associated with neuroinflammation and neuronal apoptosis. Therefore, zinc chelating strategies which block zinc mediated neuronal damage linked with cerebral hypoxia and other

  19. Exercise preconditioning exhibits neuroprotective effects on hippocampal CA1 neuronal damage after cerebral ischemia

    PubMed Central

    Shamsaei, Nabi; Khaksari, Mehdi; Erfani, Sohaila; Rajabi, Hamid; Aboutaleb, Nahid

    2015-01-01

    Recent evidence has suggested the neuroprotective effects of physical exercise on cerebral ischemic injury. However, the role of physical exercise in cerebral ischemia-induced hippocampal damage remains controversial. The aim of the present study was to evaluate the effects of pre-ischemia treadmill training on hippocampal CA1 neuronal damage after cerebral ischemia. Male adult rats were randomly divided into control, ischemia and exercise + ischemia groups. In the exercise + ischemia group, rats were subjected to running on a treadmill in a designated time schedule (5 days per week for 4 weeks). Then rats underwent cerebral ischemia induction through occlusion of common carotids followed by reperfusion. At 4 days after cerebral ischemia, rat learning and memory abilities were evaluated using passive avoidance memory test and rat hippocampal neuronal damage was detected using Nissl and TUNEL staining. Pre-ischemic exercise significantly reduced the number of TUNEL-positive cells and necrotic cell death in the hippocampal CA1 region as compared to the ischemia group. Moreover, pre-ischemic exercise significantly prevented ischemia-induced memory dysfunction. Pre-ischemic exercise mighct prevent memory deficits after cerebral ischemia through rescuing hippocampal CA1 neurons from ischemia-induced degeneration. PMID:26487851

  20. Amyloid-like aggregates of neuronal tau induced by formaldehyde promote apoptosis of neuronal cells

    PubMed Central

    Nie, Chun Lai; Wang, Xing Sheng; Liu, Ying; Perrett, Sarah; He, Rong Qiao

    2007-01-01

    Background The microtubule associated protein tau is the principle component of neurofibrillar tangles, which are a characteristic marker in the pathology of Alzheimer's disease; similar lesions are also observed after chronic alcohol abuse. Formaldehyde is a common environmental contaminant and also a metabolite of methanol. Although many studies have been done on methanol and formaldehyde intoxication, none of these address the contribution of protein misfolding to the pathological mechanism, in particular the effect of formaldehyde on protein conformation and polymerization. Results We found that unlike the typical globular protein BSA, the natively-unfolded structure of human neuronal tau was induced to misfold and aggregate in the presence of ~0.01% formaldehyde, leading to formation of amyloid-like deposits that appeared as densely staining granules by electron microscopy and atomic force microscopy, and bound the amyloid-specific dyes thioflavin T and Congo Red. The amyloid-like aggregates of tau were found to induce apoptosis in the neurotypic cell line SH-SY5Y and in rat hippocampal cells, as observed by Hoechst 33258 staining, assay of caspase-3 activity, and flow cytometry using Annexin V and Propidium Iodide staining. Further experiments showed that Congo Red specifically attenuated the caspase-3 activity induced by amyloid-like deposits of tau. Conclusion The results suggest that low concentrations of formaldehyde can induce human tau protein to form neurotoxic aggregates, which could play a role in the induction of tauopathies. PMID:17241479

  1. Igf1 and Pacap rescue cerebellar granule neurons from apoptosis via a common transcriptional program

    PubMed Central

    Maino, B; D’Agata, V; Severini, C; Ciotti, MT; Calissano, P; Copani, A; Chang, Y-C; DeLisi, C; Cavallaro, S

    2015-01-01

    A shift of the delicate balance between apoptosis and survival-inducing signals determines the fate of neurons during the development of the central nervous system and its homeostasis throughout adulthood. Both pathways, promoting or protecting from apoptosis, trigger a transcriptional program. We conducted whole-genome expression profiling to decipher the transcriptional regulatory elements controlling the apoptotic/survival switch in cerebellar granule neurons following the induction of apoptosis by serum and potassium deprivation or their rescue by either insulin-like growth factor-1 (Igf1) or pituitary adenylyl cyclase-activating polypeptide (Pacap). Although depending on different upstream signaling pathways, the survival effects of Igf1 and Pacap converged into common transcriptional cascades, thus suggesting the existence of a general transcriptional program underlying neuronal survival. PMID:26941962

  2. Methamphetamine-induced neuronal apoptosis involves the activation of multiple death pathways. Review.

    PubMed

    Cadet, Jean Lud; Jayanthi, Subramaniam; Deng, Xiaolin

    2005-11-01

    The abuse of the illicit drug methamphetamine (METH) is a major concern because it can cause terminal degeneration and neuronal cell death in the brain. METH-induced cell death occurs via processes that resemble apoptosis. In the present review, we discuss the role of various apoptotic events in the causation of METH-induced neuronal apoptosis in vitro and in vivo. Studies using comprehensive approaches to gene expression profiling have allowed for the identification of several genes that are up-regulated or down-regulated after an apoptosis-inducing dose of the drug. Further experiments have also documented the fact that the drug can cause demise of striatal enkephalinergic neurons by cross-talks between mitochondria-, endoplasmic reticulum- and receptor-mediated apoptotic events. These neuropathological observations have also been reported in models of drug-induced neuroplastic alterations used to mimic drug addiction (Nestler, 2001).

  3. Differential distribution of neurons in the gyral white matter of the human cerebral cortex.

    PubMed

    García-Marín, V; Blazquez-Llorca, L; Rodriguez, J R; Gonzalez-Soriano, J; DeFelipe, J

    2010-12-01

    The neurons in the cortical white matter (WM neurons) originate from the first set of postmitotic neurons that migrates from the ventricular zone. In particular, they arise in the subplate that contains the earliest cells generated in the telencephalon, prior to the appearance of neurons in gray matter cortical layers. These cortical WM neurons are very numerous during development, when they are thought to participate in transient synaptic networks, although many of these cells later die, and relatively few cells survive as WM neurons in the adult. We used light and electron microscopy to analyze the distribution and density of WM neurons in various areas of the adult human cerebral cortex. Furthermore, we examined the perisomatic innervation of these neurons and estimated the density of synapses in the white matter. Finally, we examined the distribution and neurochemical nature of interneurons that putatively innervate the somata of WM neurons. From the data obtained, we can draw three main conclusions: first, the density of WM neurons varies depending on the cortical areas; second, calretinin-immunoreactive neurons represent the major subpopulation of GABAergic WM neurons; and, third, the somata of WM neurons are surrounded by both glutamatergic and GABAergic axon terminals, although only symmetric axosomatic synapses were found. By contrast, both symmetric and asymmetric axodendritic synapses were observed in the neuropil. We discuss the possible functional implications of these findings in terms of cortical circuits. © 2010 Wiley-Liss, Inc.

  4. Propofol Prevents Hippocampal Neuronal Loss and Memory Impairment in Cerebral Ischemia Injury Through Promoting PTEN Degradation.

    PubMed

    Chen, Xin; Du, Ye-Mu; Xu, Feng; Liu, Dai; Wang, Yuan-Lin

    2016-09-01

    Neuroprotective effect of propofol against cerebral ischemia injury was widely investigated. However, its mechanisms remain unclear. Phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) signaling pathway is supposed as a cell survival pathway, and phosphatase and tensin homolog deleted on chromosome ten (PTEN) is a negative regulator of AKT phosphorylation. Whether PTEN was involved in the protective effect of propofol against cerebral ischemia injury was not elucidated. In this study, the function of PTEN in the acute phase of cerebral ischemia injury was investigated. Our data showed that propofol promoted the PTEN degradation in the acute phase of cerebral ischemia injury and concurrently activated AKT phosphorylation. The increase of ubiquitinated PTEN caused by cerebral ischemia injury were degraded in propofol-pretreated rats. Moreover, we evidenced that proteasome activity was stimulated in propofol-treated rats. These data pointed that PTEN degradation was facilitated in the acute phase after propofol treatment possibly through activating ubiquitin-proteasome system. Therefore, we applied PTEN inhibitor-bpV before cerebral ischemia injury. Like propofol, bpV pretreatment also mitigated cerebral ischemia injury-induced cell loss in CA1 region and memory impairment. Taken together, our data suggest that PTEN degradation is neuroprotective against cerebral ischemia injury and propofol facilitates PTEN degradation to prevent hippocampal neuronal loss and memory deficit in cerebral ischemia injury.

  5. Cytokine immunoreactivity in cortical and subcortical neurons in periventricular leukomalacia: are cytokines implicated in neuronal dysfunction in cerebral palsy?

    PubMed

    Kadhim, Hazim; Tabarki, Brahim; De Prez, Carine; Sébire, Guillaume

    2003-03-01

    The major neuropathological substrate associated with cerebral palsy (CP) is a form of white matter (WM) injury known as periventricular leukomalacia (PVL). Proinflammatory cytokines were recently shown to be implicated in PVL pathogenesis. Many PVL patients develop cortical and deep gray neuronal dysfunctions such as epilepsy, cognitive deficits and extrapyramidal disorders. The precise nature of the relationship between the WM lesion and the subsequent neuronal disorders is unclear. Cytokines were shown to exert neurotoxicity in experimental models. This raises the need to investigate a possible noxious effect by cytokines on neuronal cortical development. In situ immunohistochemical methods were applied on 22 brains from infants both with PVL (study group) and without PVL (control group) to detect any immunoreactivity for cytokines (TNF-alpha, IL-1beta, IL-6) in cortical and gray matter neurons. While cortical and other neuronal structures in PVL brains did not display noticeable pathological anomalies, strong cytokine immunoreactivity was detected in many neurons in the neocortex, hippocampus, basal ganglia and thalamus. There were, however, regional differences in cytokine labeling. In addition, there was more TNF-alpha staining than IL-1beta; IL-6 was negative. In contrast, neuronal cytokine labeling in the "control" brains was negligible. In conclusion, we report and characterize, for the first time, the in situ immunoreactivity for proinflammatory cytokines in cortical and deep gray neurons in PVL. These findings might provide insights into the neuro-anatomical correlate for the intellectual deficits and the other cortical and deep gray neuronal dysfunctions associated with PVL.

  6. Rhubarb extract has a protective role against radiation-induced brain injury and neuronal cell apoptosis.

    PubMed

    Lu, Kui; Zhang, Cheng; Wu, Wenjun; Zhou, Min; Tang, Yamei; Peng, Ying

    2015-08-01

    Oxidative stress caused by ionizing radiation is involved in neuronal damage in a number of disorders, including trauma, stroke, Alzheimer's disease and amyotrophic lateral sclerosis. Ionizing radiation can lead to the formation of free radicals, which cause neuronal apoptosis and have important roles in the development of some types of chronic brain disease. The present study evaluated the effects of varying concentrations (2, 5 and 10 µg/ml) of ethanolic rhubarb extract on the neuronal damage caused by irradiation in primary neuronal cultures obtained from the cortices of rat embryos aged 20 days. Brain damage was induced with a single dose of γ-irradiation that induced DNA fragmentation, increased lactate dehydrogenase release in neuronal cells and acted as a trigger for microglial cell proliferation. Treatment with rhubarb extract significantly decreased radiation-induced lactate dehydrogenase release and DNA fragmentation, which are important in the process of cell apoptosis. The rhubarb extract exhibited dose-dependent inhibition of lactate dehydrogenase release and neuronal cell apoptosis that were induced by the administration of ionizing radiation. The effect of a 10 µg/ml dose of rhubarb extract on the generation of reactive oxygen species (ROS) induced by radiation was also investigated. This dose led to significant inhibition of ROS generation. In conclusion, the present study showed a protective role of rhubarb extract against irradiation-induced apoptotic neuronal cell death and ROS generation.

  7. Dexmedetomidine alleviates cerebral ischemia-induced short-term memory impairment by inhibiting the expression of apoptosis-related molecules in the hippocampus of gerbils

    PubMed Central

    Choi, In-Young; Hwang, Lakkyong; Jin, Jun-Jang; Ko, Il-Gyu; Kim, Sung-Eun; Shin, Mal-Soon; Shin, Key-Moon; Kim, Chang-Ju; Park, Sung-Wook; Han, Jin-Hee; Yi, Jae-Woo

    2017-01-01

    Cerebral ischemia results from cerebrovascular occlusion, which leads to neuronal cell death and eventually causes neurological impairments. Dexmedetomidine is a potent and highly selective α2-adrenoreceptor agonist with actions such as sedation, anxiolysis, analgesia and anesthetic-sparing effects. We investigated the effect of dexmedetomidine on apoptosis in the hippocampus after transient global ischemia in gerbils. Transient global ischemia was induced by ligation of both common carotid arteries. Dexmedetomidine was administrated intraperitoneally at three respective doses (0.1, 1 and 10 µg/kg) once per day for 14 consecutive days beginning a day after surgery. Short-term memory was assessed by use of a step-down avoidance task. Apoptosis was evaluated by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling assay, immunohistochemistry for caspase-3, and western blot analysis of Bcl-2-associated X protein, B-cell lymphoma 2, Bid, cytochrome c, apoptotic protease activating factor-1 and caspase-9 in the hippocampus. Induction of global ischemia deteriorated short-term memory by enhancing the expression of apoptosis-related molecules in the hippocampus. Treatment with dexmedetomidine suppressed the expression of apoptosis-related molecules under ischemic conditions, resulting in short-term memory improvement. Under normal conditions, dexmedetomidine exerted no significant effect on apoptosis in the hippocampus. The present results suggest that the α2-adrenoceptor agonist dexmedetomidine may be a useful therapeutic agent for the treatment of ischemic brain diseases. PMID:28123477

  8. Apoptosis of glutamatergic neurons fails to trigger a neurogenic response in the adult neocortex.

    PubMed

    Diaz, Frank; McKeehan, Nicholas; Kang, Wenfei; Hébert, Jean M

    2013-04-10

    Adult neurogenesis is actively studied in part because of the potential to manipulate endogenous neural stem and progenitor cells for tissue repair. Although constitutive generation of neurons in the adult rodent olfactory bulb and hippocampal dentate gyrus is widely accepted and stroke-induced generation of striatal inhibitory neurons consistently observed, evidence supporting the generation of neurons in the neocortex after neuronal loss remains slim. Nevertheless, a few studies suggested that targeted apoptosis of neocortical glutamatergic neurons could trigger the generation of new ones in the adult brain. In light of such studies, we tested whether apoptosis of glutamatergic cortical neurons using two novel transgenic approaches in mice, an inducible Caspase-8 protein and an inducible diphtheria toxin gene, results in new neurons. After a thorough analysis, no new neurons were detected in the neocortex. Interestingly, an increase in the expression of the neuroblast marker DCX was observed in both models, in some cases in cells with morphologies previously associated with poststroke neuroblasts, but DCX(+) cells coexpressed the oligodendrocyte precursor marker Olig2, suggesting caution when using DCX as a marker for neuroblasts after injury. Given that the adult neocortex lacks an innate potential to regenerate lost glutamatergic neurons, future strategies should concentrate on manipulating the differentiation potential of endogenous or exogenous precursor cells.

  9. Protective effects of propofol against whole cerebral ischemia/reperfusion injury in rats through the inhibition of the apoptosis-inducing factor pathway.

    PubMed

    Tao, Tao; Li, Chun-Lei; Yang, Wan-Chao; Zeng, Xian-Zhang; Song, Chun-Yu; Yue, Zi-Yong; Dong, Hong; Qian, Hua

    2016-08-01

    Cerebral ischemia/reperfusion (I/R) injury could cause neural apoptosis that involved the signaling cascades. Cytochrome c release from the mitochondria and the followed activation of caspase 9 and caspase 3 are the important steps. Now, a new mitochondrial protein, apoptosis-inducing factor (AIF), has been shown to have relationship with the caspase-independent apoptotic pathway. In this study, we investigated the protective effects of propofol through inhibiting AIF-mediated apoptosis induced by whole cerebral I/R injury in rats. 120 Wistar rats that obtained the permission of the animal care committee of Harbin Medical University were randomly divided into three groups: sham group (S group), cerebral ischemia/reperfusion injury group (I/R group), and propofol treatment group (P group). Propofol (1.0mg/kg/min) was administered intravenously for 1h before the induction of ischemia in P group. The apoptotic rate in three groups was detected by flow cytometry after 24h of reperfusion. The mitochondrial membrane potential (MMP) changes were detected via microplate reader. The expressions of B-cell leukemia-2 (Bcl-2), Bcl-2 associated X protein (Bax) and AIF were evaluated using Western blot after 6h, 24h and 48h of reperfusion. The results of our study showed that apoptotic level was lower in P group compared with I/R group and propofol could protect MMP. The ratio of Bcl-2/Bax was significantly higher in P group compared with I/R group. The translocation of AIF from mitochondrial to nucleus was lower in P group than that in I/R group. Our findings suggested that the protective effects of propofol on cerebral I/R injury might be associated with inhibiting translocation of AIF from mitochondrial to the nucleus in hippocampal neurons. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Single-cell resolution mapping of neuronal damage in acute focal cerebral ischemia using thallium autometallography.

    PubMed

    Stöber, Franziska; Baldauf, Kathrin; Ziabreva, Iryna; Harhausen, Denise; Zille, Marietta; Neubert, Jenni; Reymann, Klaus G; Scheich, Henning; Dirnagl, Ulrich; Schröder, Ulrich H; Wunder, Andreas; Goldschmidt, Jürgen

    2014-01-01

    Neuronal damage shortly after onset or after brief episodes of cerebral ischemia has remained difficult to assess with clinical and preclinical imaging techniques as well as with microscopical methods. We here show, in rodent models of middle cerebral artery occlusion (MCAO), that neuronal damage in acute focal cerebral ischemia can be mapped with single-cell resolution using thallium autometallography (TlAMG), a histochemical technique for the detection of the K(+)-probe thallium (Tl(+)) in the brain. We intravenously injected rats and mice with thallium diethyldithiocarbamate (TlDDC), a lipophilic chelate complex that releases Tl(+) after crossing the blood-brain barrier. We found, within the territories of the affected arteries, areas of markedly reduced neuronal Tl(+) uptake in all animals at all time points studied ranging from 15 minutes to 24 hours after MCAO. In large lesions at early time points, areas with neuronal and astrocytic Tl(+) uptake below thresholds of detection were surrounded by putative penumbral zones with preserved but diminished Tl(+) uptake. At 24 hours, the areas of reduced Tl(+)uptake matched with areas delineated by established markers of neuronal damage. The results suggest the use of (201)TlDDC for preclinical and clinical single-photon emission computed tomography (SPECT) imaging of hyperacute alterations in brain K(+) metabolism and prediction of tissue viability in cerebral ischemia.

  11. Angiotensin protects cortical neurons from hypoxic-induced apoptosis via the angiotensin type 2 receptor.

    PubMed

    Grammatopoulos, Tom; Morris, Katherine; Ferguson, Paul; Weyhenmeyer, James

    2002-03-28

    The effects of angiotensin on mouse cortical neuronal cultures exposed to chemical-induced hypoxia was investigated. Cultures exposed to 10 mM sodium azide for 5 min showed a 17% increase in apoptosis when assayed 24 h postinsult. The N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 blocked sodium azide-induced cell death suggesting that the NMDA receptor contributes to the mediated cell death. Pretreatment of cultured neurons with angiotensin decreased sodium azide-induced apoptosis by 94%. When the AT(1) receptor was blocked by its receptor antagonist, losartan, angiotensin activation of the AT(2) receptor completely inhibited sodium azide-induced apoptosis. Pretreatment of neurons with the AT(2) receptor antagonist PD123319 resulted in angiotensin reducing sodium azide-induced apoptosis by 48%. These results demonstrate that angiotensin can significantly attenuate sodium azide-induced apoptosis primarily through activation of the AT(2) receptor and suggests that angiotensin may have a protective role in neurons undergoing ischemic injury.

  12. Hydrogen peroxide induces apoptosis in cerebral vascular smooth muscle cells: possible relation to neurodegenerative diseases and strokes.

    PubMed

    Li, Jianfeng; Li, Wenyan; Su, Jialin; Liu, Weimin; Altura, Bella T; Altura, Burton M

    2003-12-15

    Recently, reactive oxygen species (ROS) have been suggested as important mediators of brain damage in a number of disease states, including traumatic brain injury, neurodegenerative diseases and strokes. Apoptosis has been suggested to play an important role in neurodegenerative diseases, traumatic brain injury and strokes. The aim of this study was to determine whether or not cerebral vascular smooth muscle cells (CVSMCs) undergo apoptosis following treatment with hydrogen peroxide (H2O2). Herein, we demonstrate, for the first time, that H2O2 can induce apoptosis in a concentration-dependent manner in primary cultured CVSMCs, as measured by several morphological and biochemical criteria. H2O2-induced apoptosis may be initiated by stimulating Ca2+-dependent endonuclease activity. The present new data suggest that apoptosis in cerebral VSMCs, induced by ROS, such as H2O2, could play important roles in neruodegenerative processes, traumatic brain injury and strokes.

  13. Bifunctional apoptosis inhibitor (BAR) protects neurons from diverse cell death pathways.

    PubMed

    Roth, W; Kermer, P; Krajewska, M; Welsh, K; Davis, S; Krajewski, S; Reed, J C

    2003-10-01

    The bifunctional apoptosis regulator (BAR) is a multidomain protein that was originally identified as an inhibitor of Bax-induced apoptosis. Immunoblot analysis of normal human tissues demonstrated high BAR expression in the brain, compared to low or absent expression in other organs. Immunohistochemical staining of human adult tissues revealed that the BAR protein is predominantly expressed by neurons in the central nervous system. Immunofluorescence microscopy indicated that BAR localizes mainly to the endoplasmic reticulum (ER) of cells. Overexpression of BAR in CSM 14.1 neuronal cells resulted in significant protection from a broad range of cell death stimuli, including agents that activate apoptotic pathways involving mitochondria, TNF-family death receptors, and ER stress. Downregulation of BAR by antisense oligonucleotides sensitized neuronal cells to induction of apoptosis. Moreover, the search for novel interaction partners of BAR identified several candidate proteins that might contribute to the regulation of neuronal apoptosis (HIP1, Hippi, and Bap31). Taken together, the expression pattern and functional data suggest that the BAR protein is involved in the regulation of neuronal survival.

  14. Generating Neuronal Diversity in the Mammalian Cerebral Cortex

    PubMed Central

    Lodato, Simona; Arlotta, Paola

    2016-01-01

    The neocortex is the part of the brain responsible for the execution of higher-order brain functions, including cognition, sensory perception and sophisticated motor control. During evolution, the neocortex has developed an unparalleled neuronal diversity, which still remains partly unclassified and unmapped at the functional level. Here, we first broadly review the structural blueprint of the neocortex and discuss the current classification of its neuronal diversity. We then cover the principles and mechanisms that build neuronal diversity during cortical development and consider the impact of neuronal class-specific identity in shaping cortical connectivity and function. PMID:26359774

  15. MORIN MITIGATES OXIDATIVE STRESS, APOPTOSIS AND INFLAMMATION IN CEREBRAL ISCHEMIC RATS.

    PubMed

    Chen, Yanrong; Li, Yanke; Xu, Huali; Li, Gang; Ma, Yunxia; Pang, Yu Jun

    2017-01-01

    Morin is a flavanoid which exhibits potent antioxidant activity in various oxidative stress related diseases. The current study was attempted to scrutinize the preclinical bio-efficacy of morin on focal ischemia. The animal model of focal cerebral ischemic injury was done by midbrain carotid artery occlusion (MCAO) method, followed by Morin (30mg/kg) administration for seven days. The outcome of the study showed that treatment with morin displayed positive effects in reducing the focal cerebral ischemia. This effect was evident with the improvements in neurological deficits, reduction in MDA content and elevation of antioxidant levels (SOD, GSH and Gpx). Furthermore, protein expression of Bax and caspase-3 were effectively down-regulated, whilst the expression of Bcl-2 was significantly elevated. On the other hand, the mRNA expression of proinflammatory cytokines was significantly reduced in focal cerebral ischemic rats upon morin intervention. Thus, the beneficial effects of morin on cerebral ischemia assault may result from the reduction of oxidative stress, inhibition of apoptosis and inflammation. The neuroprotective effects of morin supplement may serve as potent adjuvant in the amelioration of ischemic stroke.

  16. CALHM1 deficiency impairs cerebral neuron activity and memory flexibility in mice

    PubMed Central

    Vingtdeux, Valérie; Chang, Eric H.; Frattini, Stephen A.; Zhao, Haitian; Chandakkar, Pallavi; Adrien, Leslie; Strohl, Joshua J.; Gibson, Elizabeth L.; Ohmoto, Makoto; Matsumoto, Ichiro; Huerta, Patricio T.; Marambaud, Philippe

    2016-01-01

    CALHM1 is a cell surface calcium channel expressed in cerebral neurons. CALHM1 function in the brain remains unknown, but recent results showed that neuronal CALHM1 controls intracellular calcium signaling and cell excitability, two mechanisms required for synaptic function. Here, we describe the generation of Calhm1 knockout (Calhm1−/−) mice and investigate CALHM1 role in neuronal and cognitive functions. Structural analysis revealed that Calhm1−/− brains had normal regional and cellular architecture, and showed no evidence of neuronal or synaptic loss, indicating that CALHM1 deficiency does not affect brain development or brain integrity in adulthood. However, Calhm1−/− mice showed a severe impairment in memory flexibility, assessed in the Morris water maze, and a significant disruption of long-term potentiation without alteration of long-term depression, measured in ex vivo hippocampal slices. Importantly, in primary neurons and hippocampal slices, CALHM1 activation facilitated the phosphorylation of NMDA and AMPA receptors by protein kinase A. Furthermore, neuronal CALHM1 activation potentiated the effect of glutamate on the expression of c-Fos and C/EBPβ, two immediate-early gene markers of neuronal activity. Thus, CALHM1 controls synaptic activity in cerebral neurons and is required for the flexible processing of memory in mice. These results shed light on CALHM1 physiology in the mammalian brain. PMID:27066908

  17. The Rai (Shc C) adaptor protein regulates the neuronal stress response and protects against cerebral ischemia

    PubMed Central

    Troglio, Flavia; Echart, Cinara; Gobbi, Alberto; Pawson, Tony; Pelicci, Pier Giuseppe; De Simoni, Maria Grazia; Pelicci, Giuliana

    2004-01-01

    Rai (Shc C or N-Shc) is a neuron-specific member of the family of Shc-like adaptor proteins. Rai functions in the cytoplasmic propagation of Ret-dependent survival signals and regulates, in vivo, the number of sympathetic neurons. We report here a function of Rai, i.e., the regulation of the neuronal adaptive response to environmental stresses. We demonstrate that (i) primary cultures of cortical neurons from Rai-/- mice are more sensitive to apoptosis induced by hypoxia or oxidative stress; (ii) in Rai-/- mice, ischemia/reperfusion injury induces severe neurological deficits, increased apoptosis and size of the infarct area, and significantly higher mortality; and (iii) Rai functions as a stress-response gene that increases phosphatidylinositol 3-kinase activation and Akt phosphorylation after hypoxic or oxidation insults. These data suggest that Rai has a functional neuroprotective role in brain injury, with possible implications in the treatment of stroke. PMID:15494442

  18. Expression of the RNA-binding protein TIAR is increased in neurons after ischemic cerebral injury.

    PubMed

    Jin, K; Li, W; Nagayama, T; He, X; Sinor, A D; Chang, J; Mao, X; Graham, S H; Simon, R P; Greenberg, D A

    2000-03-15

    T-cell restricted intracellular antigen-related protein (TIAR) is an RNA recognition motif-type RNA-binding protein that has been implicated in the apoptotic death of T-lymphocytes and retinal pigment epithelial cells. Western blots prepared with a monoclonal antibody against TIAR showed expression in normal rat hippocampus, and induction by 15 min of global cerebral ischemia. This increased expression was evident at 8 hr after ischemia and maximal at 24 hr, whereas expression at 72 hr was reduced below basal levels. Expression of TIAR protein was also increased in parietal cortex 6 and 24 hr after 90 min of focal cerebral ischemia induced by middle cerebral artery (MCA) occlusion, as well as in cultured cortical neurons and astroglia after exposure to hypoxia in vitro. Immunocytochemistry showed that increased expression of TIAR occurred mainly in the CA1 sector of hippocampus 24 hr after global ischemia, and in cortical and striatal neurons 24 hr after 20 or 90 min of focal ischemia. Double-labeling studies showed that TIAR protein expression was co-localized with DNA damage in neuronal cells. The findings suggest that TIAR may be involved in neuronal cell death after cerebral ischemic injury.

  19. The Role of Neuronal Signaling in Controlling Cerebral Blood Flow

    ERIC Educational Resources Information Center

    Drake, Carrie T.; Iadecola, Costantino

    2007-01-01

    Well-regulated blood flow within the brain is vital to normal function. The brain's requirement for sufficient blood flow is ensured by a tight link between neural activity and blood flow. The link between regional synaptic activity and regional cerebral blood flow, termed functional hyperemia, is the basis for several modern imaging techniques…

  20. The Role of Neuronal Signaling in Controlling Cerebral Blood Flow

    ERIC Educational Resources Information Center

    Drake, Carrie T.; Iadecola, Costantino

    2007-01-01

    Well-regulated blood flow within the brain is vital to normal function. The brain's requirement for sufficient blood flow is ensured by a tight link between neural activity and blood flow. The link between regional synaptic activity and regional cerebral blood flow, termed functional hyperemia, is the basis for several modern imaging techniques…

  1. [Effect of nootropic agents on impulse activity of cerebral cortex neurons].

    PubMed

    Iasnetsov, V V; Pravdivtsev, V A; Krylova, I N; Kozlov, S B; Provornova, N A; Ivanov, Iu V; Iasnetsov, V V

    2001-01-01

    The effect of nootropes (semax, mexidol, and GVS-111) on the activity of individual neurons in various cerebral cortex regions was studied by microelectrode and microionophoresis techniques in cats immobilized by myorelaxants. It was established that the inhibiting effect of mexidol upon neurons in more than half of cases is prevented or significantly decreased by the GABA antagonists bicuculline and picrotoxin. The inhibiting effect of semax and GVS-111 upon neurons in more than half of cases is related to stimulation of the M-choline and NMDA receptors, respectively.

  2. Induction of nitric oxide-dependent apoptosis in motor neurons by zinc-deficient superoxide dismutase.

    PubMed

    Estévez, A G; Crow, J P; Sampson, J B; Reiter, C; Zhuang, Y; Richardson, G J; Tarpey, M M; Barbeito, L; Beckman, J S

    1999-12-24

    Mutations in copper, zinc superoxide dismutase (SOD) have been implicated in the selective death of motor neurons in 2 percent of amyotrophic lateral sclerosis (ALS) patients. The loss of zinc from either wild-type or ALS-mutant SODs was sufficient to induce apoptosis in cultured motor neurons. Toxicity required that copper be bound to SOD and depended on endogenous production of nitric oxide. When replete with zinc, neither ALS-mutant nor wild-type copper, zinc SODs were toxic, and both protected motor neurons from trophic factor withdrawal. Thus, zinc-deficient SOD may participate in both sporadic and familial ALS by an oxidative mechanism involving nitric oxide.

  3. MADP, a salidroside analog, protects hippocampal neurons from glutamate induced apoptosis.

    PubMed

    Xian, Hua; Zhao, Jing; Zheng, Yuan; Wang, Meihong; Huang, Jun; Wu, Bingxin; Sun, Cheng; Yang, Yumin

    2014-05-08

    To investigate the anti-apoptotic effect of MADP, an analog of salidroside, against glutamate induced apoptosis in the cultured rat hippocampal neurons. Cytotoxicity was determined by the MTT method and lactate dehydrogenase release to the medium. Cell apoptosis was evaluated by Hoechst 33342 staining, TUNEL assay and flow cytometric analysis. Western blotting was applied for detecting protein levels of cellular signaling molecules. Our results showed that glutamate exposure significantly induces cell apoptosis, whereas the pretreatment of salidroside or MADP remarkably improves cell viability. Most importantly, the anti-apoptotic effect of MADP against glutamate insult is superior to salidroside. To explore the involved mechanisms, we measured some pro-apoptotic and anti-apoptotic protein levels, and several cell survival signaling pathways were analyzed as well. No visible alterations in Bcl-2 and Bax protein levels were observed by MADP or salidroside. Akt and JNK phosphorylation was robustly stimulated by MADP in the glutamate-treated neurons. Salidroside treatment results in a slight activation in Akt, while no significant alteration in JNK activity was observed. MADP exhibits higher capacity to attenuate glutamate induced cell apoptosis in the cultured rat hippocampal neurons, suggesting that MADP might be a better candidate than salidroside for developing novel drugs treating neuron loss associated disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Up-regulation of Vps4A promotes neuronal apoptosis after intracerebral hemorrhage in adult rats.

    PubMed

    Ren, Jianbing; Yuan, Debin; Xie, Lili; Tao, Xuelei; Duan, Chenwei; Bao, Yifeng; He, Yunfeng; Ge, Jianbin; Lu, Hongjian

    2017-04-01

    Vps4, vacuolar protein sorting 4, belongs to ATPases Associated with diverse cellular Activities (AAA) protein family which is made up of Vps4A and Vps4B. Previous studies demonstrated that Vps4A plays vital roles in diverse aspects such as virus budding, the efficient transport of H-Ras to the PM (plasma membrane) and the involvement in the MVB (multivesiculate bodies) pathway. Interestingly, Vps4A is also expressed in the brain. However, the distribution and function of Vps4A in ICH diseases remain unclear. In this study, we show that Vps4A may be involved in neuronal apoptosis during pathophysiological processes of intracerebral hemorrhage (ICH). Based on the results of Western blot and immunohistochemistry, we found a remarkable up-regulation of Vps4A expression surrounding the hematoma after ICH. Double labeled immunofluorescence showed that Vps4A was co-expressed with NeuN but rarely with astrocytes and microglia. Morever, we detected that neuronal apoptosis marker active caspase-3 had co-localizations with Vps4A. Additionaly, Vps4A knockdown in vitro specifically leads to decreasing neuronal apoptosis coupled with increased Akt phosphorylation. All datas suggested that Vps4A was involved in promoting neuronal apoptosis via inhibiting Akt phosphorylation after ICH.

  5. CaMKII inhibition promotes neuronal apoptosis by transcriptionally upregulating Bim expression.

    PubMed

    Zhao, Yiwei; Zhu, Lin; Yu, Shaojun; Zhu, Jing; Wang, Chong

    2016-09-28

    The effects of Ca/calmodulin-dependent protein kinase II (CaMKII) on neuronal apoptosis are complex and contradictory, and the underlying mechanisms remain unclear. Bcl-2-interacting mediator of cell death (Bim) is an important proapoptotic protein under many physiological and pathophysiological conditions. However, there is no evidence that CaMKII and Bim are mechanistically linked in neuronal apoptosis. In this study, we showed that CaMKII inhibition by the inhibitors KN-62 and myristoylated autocamtide-2-related inhibitory peptide promoted apoptosis in cerebellar granule neurons in a dose-dependent manner. CaMKII inhibition increased Bim protein and messenger RNA levels. The expression of early growth response factor-1, a transcription factor of Bim, was also induced by CaMKII inhibitors. These data suggested that CaMKII repressed the transcriptional expression of Bim. Moreover, knockdown of Bim using small interfering RNAs attenuated the proapoptotic effects of CaMKII inhibition. Taken together, this is the first report to show that CaMKII inhibition transcriptionally upregulates Bim expression to promote neuronal apoptosis, providing new insights into the proapoptotic mechanism of CaMKII inhibition.

  6. The BH3-only protein Puma is both necessary and sufficient for neuronal apoptosis induced by DNA damage in sympathetic neurons.

    PubMed

    Wyttenbach, Andreas; Tolkovsky, Aviva M

    2006-03-01

    DNA damage activates apoptosis in several neuronal populations and is an important component of neuropathological conditions. While it is well established that neuronal apoptosis, induced by DNA damage, is dependent on the key cell death regulators p53 and Bax, it is unknown which proteins link the p53 signal to Bax. Using rat sympathetic neurons as an in vitro model of neuronal apoptosis, we show that cytosine arabinoside is a DNA damaging drug that induces the expression of the BH3-only pro-apoptotic genes Noxa, Puma and Bim. Increased expression occurred after p53 activation, measured by its phosphorylation at serine 15, but prior to the conformational change of Bax at the mitochondria, cytochrome c (cyt c) release and apoptosis. Hence Noxa, Puma and Bim could potentially link p53 to Bax. We directly tested this hypothesis by the use of nullizygous mice. We show that Puma, but not Bim or Noxa, is a crucial mediator of DNA damage-induced neuronal apoptosis. Despite the powerful pro-apoptotic effects of overexpressed Puma in Bax-expressing neurons, Bax nullizygous neurons were resistant to Puma-induced death. Therefore, Puma provides the critical link between p53 and Bax, and is both necessary and sufficient to mediate DNA damage-induced apoptosis of sympathetic neurons.

  7. GSK-3 Mouse Models to Study Neuronal Apoptosis and Neurodegeneration

    PubMed Central

    Gómez-Sintes, Raquel; Hernández, Félix; Lucas, José J.; Avila, Jesús

    2011-01-01

    Increased GSK-3 activity is believed to contribute to the etiology of chronic disorders like Alzheimer’s disease (AD), schizophrenia, diabetes, and some types of cancer, thus supporting therapeutic potential of GSK-3 inhibitors. Numerous mouse models with modified GSK-3 have been generated in order to study the physiology of GSK-3, its implication in diverse pathologies and the potential effect of GSK-3 inhibitors. In this review we have focused on the relevance of these mouse models for the study of the role of GSK-3 in apoptosis. GSK-3 is involved in two apoptotic pathways, intrinsic and extrinsic pathways, and plays opposite roles depending on the apoptotic signaling process that is activated. It promotes cell death when acting through intrinsic pathway and plays an anti-apoptotic role if the extrinsic pathway is occurring. It is important to dissect this duality since, among the diseases in which GSK-3 is involved, excessive cell death is crucial in some illnesses like neurodegenerative diseases, while a deficient apoptosis is occurring in others such as cancer or autoimmune diseases. The clinical application of a classical GSK-3 inhibitor, lithium, is limited by its toxic consequences, including motor side effects. Recently, the mechanism leading to activation of apoptosis following chronic lithium administration has been described. Understanding this mechanism could help to minimize side effects and to improve application of GSK-3 inhibitors to the treatment of AD and to extend the application to other diseases. PMID:22110426

  8. TRH regulates action potential shape in cerebral cortex pyramidal neurons.

    PubMed

    Rodríguez-Molina, Víctor; Patiño, Javier; Vargas, Yamili; Sánchez-Jaramillo, Edith; Joseph-Bravo, Patricia; Charli, Jean-Louis

    2014-07-07

    Thyrotropin releasing hormone (TRH) is a neuropeptide with a wide neural distribution and a variety of functions. It modulates neuronal electrophysiological properties, including resting membrane potential, as well as excitatory postsynaptic potential and spike frequencies. We explored, with whole-cell patch clamp, TRH effect on action potential shape in pyramidal neurons of the sensorimotor cortex. TRH reduced spike and after hyperpolarization amplitudes, and increased spike half-width. The effect varied with dose, time and cortical layer. In layer V, 0.5µM of TRH induced a small increase in spike half-width, while 1 and 5µM induced a strong but transient change in spike half-width, and amplitude; after hyperpolarization amplitude was modified at 5µM of TRH. Cortical layers III and VI neurons responded intensely to 0.5µM TRH; layer II neurons response was small. The effect of 1µM TRH on action potential shape in layer V neurons was blocked by G-protein inhibition. Inhibition of the activity of the TRH-degrading enzyme pyroglutamyl peptidase II (PPII) reproduced the effect of TRH, with enhanced spike half-width. Many cortical PPII mRNA+ cells were VGLUT1 mRNA+, and some GAD mRNA+. These data show that TRH regulates action potential shape in pyramidal cortical neurons, and are consistent with the hypothesis that PPII controls its action in this region. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. In Utero Bisphenol A Exposure Induces Abnormal Neuronal Migration in the Cerebral Cortex of Mice

    PubMed Central

    Ling, Wenting; Endo, Toshihiro; Kubo, Ken-ichiro; Nakajima, Kazunori; Kakeyama, Masaki; Tohyama, Chiharu

    2016-01-01

    Bisphenol A (BPA) has been known to have endocrine-disrupting activity to induce reproductive and behavioral abnormalities in offspring of laboratory animal species. However, morphological basis of this abnormality during brain development is largely unknown. Cerebral cortex plays a crucial role in higher brain function, and its precisely laminated structure is formed by neuronal migration. In the present study, transfecting a plasmid (pCAG-mCherry) by in utero electroporation (IUE), we visualized developing neurons and investigated the possible effects of in utero BPA exposure on neuronal migration. Pregnant mice were exposed to BPA by osmotic pump at estimated daily doses of 0, 40 (BPA-40), or 400 (BPA-400) μg/kg from embryonic day 14.5 (E14.5) to E18.5. IUE was performed at E14.5 and neuronal migration was analyzed at E18.5. Compared with the control group, neuronal migration in the cortical plate was significantly decreased in the BPA-40 group; however, there was no significant difference in the BPA-400 group. Among several neuronal migration-related genes and cortical layer-specific genes, TrkB in the BPA-400 group was found significantly upregulated. In conclusion, in utero exposure to low BPA dose was found to disrupt neuronal migration in the cerebral cortex in a dose-specific manner. PMID:26869994

  10. In Utero Bisphenol A Exposure Induces Abnormal Neuronal Migration in the Cerebral Cortex of Mice.

    PubMed

    Ling, Wenting; Endo, Toshihiro; Kubo, Ken-Ichiro; Nakajima, Kazunori; Kakeyama, Masaki; Tohyama, Chiharu

    2016-01-01

    Bisphenol A (BPA) has been known to have endocrine-disrupting activity to induce reproductive and behavioral abnormalities in offspring of laboratory animal species. However, morphological basis of this abnormality during brain development is largely unknown. Cerebral cortex plays a crucial role in higher brain function, and its precisely laminated structure is formed by neuronal migration. In the present study, transfecting a plasmid (pCAG-mCherry) by in utero electroporation (IUE), we visualized developing neurons and investigated the possible effects of in utero BPA exposure on neuronal migration. Pregnant mice were exposed to BPA by osmotic pump at estimated daily doses of 0, 40 (BPA-40), or 400 (BPA-400) μg/kg from embryonic day 14.5 (E14.5) to E18.5. IUE was performed at E14.5 and neuronal migration was analyzed at E18.5. Compared with the control group, neuronal migration in the cortical plate was significantly decreased in the BPA-40 group; however, there was no significant difference in the BPA-400 group. Among several neuronal migration-related genes and cortical layer-specific genes, TrkB in the BPA-400 group was found significantly upregulated. In conclusion, in utero exposure to low BPA dose was found to disrupt neuronal migration in the cerebral cortex in a dose-specific manner.

  11. Electrical Excitability of Early Neurons in the Human Cerebral Cortex during the Second Trimester of Gestation

    PubMed Central

    Moore, Anna R.; Filipovic, Radmila; Mo, Zhicheng; Rasband, Matthew N.; Zecevic, Nada

    2009-01-01

    Information about development of the human cerebral cortex (proliferation, migration, and differentiation of neurons) is largely based on postmortem histology. Physiological properties of developing human cortical neurons are difficult to access experimentally and therefore remain largely unexplored. Animal studies have shown that information about the arousal of electrical activity in individual cells within fundamental cortical zones (subventricular zone [SVZ], intermediate zone, subplate [SP], and cortical plate [CP]) is necessary for understanding normal brain development. Here we ask where, in what cortical zone, and when, in what gestational week (gw), human neurons acquire the ability to generate nerve impulses (action potentials [APs]). We performed electrical recordings from individual cells in acute brain slices harvested postmortem from the human fetal cerebral cortex (16–22 gw). Tetrodotoxin-sensitive Na+ current occurs more frequently among CP cells and with significantly greater peak amplitudes than in SVZ. As early as 16 gw, a relatively small population of CP neurons (27%) was able to generate sodium APs upon direct current injection. Neurons located in the SP exhibited the highest level of cellular differentiation, as judged by their ability to fire repetitive APs. At 19 gw, a fraction of human CP and SP neurons possess βIV spectrin–positive axon initial segments populated with voltage-gated sodium channels (PanNav). These results yield the first physiological characterization of developing human fetal cortical neurons with preserved morphologies in intact surrounding brain tissue. PMID:19015375

  12. Potentiation of the depression by adenosine of rat cerebral cortical neurones by progestational agents.

    PubMed Central

    Phillis, J. W.

    1986-01-01

    The effects of four progestational agents pregnenolone sulphate, cyproterone acetate, norethindrone acetate and progesterone, on adenosine-evoked depression of the firing of rat cerebral cortical neurones have been studied. When applied iontophoretically, pregnenolone sulphate, cyproterone, and norethindrone enhanced the actions of iontophoretically applied adenosine and failed to potentiate the depressant effects of adenosine 5'-N-ethylcarboxamide and gamma-aminobutyric acid. Cyproterone acetate (50 micrograms kg-1) and progesterone (200 micrograms kg-1) administered intravenously enhanced the depressant actions of iontophoretically applied adenosine. When applied by large currents, cyproterone, and less frequently norethindrone, depressed the firing of cerebral cortical neurones. The depressant effects of cyproterone were antagonized by caffeine. Pregnenolone sulphate tended to excite cortical neurones but neither this action, nor its potentiation of adenosine were reproduced by application of sulphate ions. It is hypothesized that some of the psychotropic actions of progestational agents may involve an enhancement of 'purinergic' tone in the central nervous system. PMID:3814905

  13. Control of Neuronal Migration and Aggregation by Reelin Signaling in the Developing Cerebral Cortex.

    PubMed

    Hirota, Yuki; Nakajima, Kazunori

    2017-01-01

    The mammalian cerebral neocortex has a well-organized laminar structure, achieved by the highly coordinated control of neuronal migration. During cortical development, excitatory neurons born near the lateral ventricle migrate radially to reach their final positions to form the cortical plate. During this process, dynamic changes are observed in the morphologies and migration modes, including multipolar migration, locomotion, and terminal translocation, of the newborn neurons. Disruption of these migration processes can result in neuronal disorders such as lissencephaly and periventricular heterotopia. The extracellular protein, Reelin, mainly secreted by the Cajal-Retzius neurons in the marginal zone during development, plays a crucial role in the neuronal migration and neocortical lamination. Reelin signaling, which exerts essential roles in the formation of the layered neocortex, is triggered by the binding of Reelin to its receptors, ApoER2 and VLDLR, followed by phosphorylation of the Dab1 adaptor protein. Accumulating evidence suggests that Reelin signaling controls multiple steps of neuronal migration, including the transition from multipolar to bipolar neurons, terminal translocation, and termination of migration beneath the marginal zone. In addition, it has been shown that ectopically expressed Reelin can cause neuronal aggregation via an N-cadherin-mediated manner. This review attempts to summarize our knowledge of the roles played by Reelin in neuronal migration and the underlying mechanisms.

  14. Inhibition of N-methyl-D-aspartate receptors increases paraoxon-induced apoptosis in cultured neurons

    SciTech Connect

    Wu Xuan; Tian Feng; Okagaki, Peter; Marini, Ann M. . E-mail: amarini@usuhs.mil

    2005-10-01

    Organophosphorus (OP) compounds, used as insecticides and chemical warfare agents, are potent neurotoxins. We examined the neurotoxic effect of paraoxon (O,O-diethyl O-p-nitrophenyl phosphate), an organophosphate compound, and the role of NMDA receptors as a mechanism of action in cultured cerebellar granule cells. Paraoxon is neurotoxic to cultured rat cerebellar granule cells in a time- and concentration-dependent manner. Cerebellar granule cells are less sensitive to the neurotoxic effects of paraoxon on day in vitro (DIV) 4 than neurons treated on DIV 8. Surprisingly, the N-methyl-D-aspartate (NMDA) receptor antagonist, MK-801, enhances paraoxon-mediated neurotoxicity suggesting that NMDA receptors may play a protective role. Pretreatment with a subtoxic concentration of N-methyl-D-aspartate (NMDA) [100 {mu}M] protects about 40% of the vulnerable neurons that would otherwise die from paraoxon-induced neurotoxicity. Moreover, addition of a neuroprotective concentration of NMDA 3 h after treatment with paraoxon provides the same level of protection. Because paraoxon-mediated neuronal cell death is time-dependent, we hypothesized that apoptosis may be involved. Paraoxon increases apoptosis about 10-fold compared to basal levels. The broad-spectrum caspase inhibitor (Boc-D-FMK) and the caspase-9-specific inhibitor (Z-LEHD-FMK) protect against paraoxon-mediated apoptosis, paraoxon-stimulated caspase-3 activity and neuronal cell death. MK-801 increases, whereas NMDA blocks paraoxon-induced apoptosis and paraoxon-stimulated caspase-3 activity. These results suggest that activation of NMDA receptors protect neurons against paraoxon-induced neurotoxicity by blocking apoptosis initiated by paraoxon.

  15. Gender differences in the human cerebral cortex: more neurons in males; more processes in females.

    PubMed

    Rabinowicz, T; Dean, D E; Petetot, J M; de Courten-Myers, G M

    1999-02-01

    This study's objective was to investigate morphometric gender differences of the cerebral cortex in six males and five females, 12 to 24 years old. Though human brains lack sexual dimorphism on routine neuropathologic examinations, gender-specific brain weight, functional, and morphologic differences exist, suggesting that cortical differences may be found. Yet the cerebral cortex may be exempt from gender differences, as demonstrated by the fact that normal males and females perform comparably on intelligence tests. Stereologic morphometry on standardized histologic sections from 30 bilateral cortical loci determined cortical thickness, neuronal density, and derived neuronal number estimates. The mean +/- SD cortical thickness of the 60 loci examined was similar in males and females with right and left hemispheric gender ratios being balanced. In contrast, the average neuronal density of the same 60 loci was significantly higher in the male group than in the female group, and the corresponding mean male-to-female ratios were 1.18 in the right and 1.13 in the left hemisphere, which differ significantly from each other and from the balanced cortical thickness ratios. Estimates of neuronal numbers -- the product of neuronal thickness times density -- were 13% higher in males than in females, with mean male-to-female ratios of 1.13 in both hemispheres. The data provide morphologic evidence of considerable cerebral cortical dimorphism with the demonstration of significantly higher neuronal densities and neuronal number estimates in males, though with similar mean cortical thickness, implying a reciprocal increase in neuropil/neuronal processes in the female cortex.

  16. Exacerbation of Apoptosis of Cortical Neurons Following Traumatic Brain Injury in Par-4 Transgenic Mice

    PubMed Central

    Payette, Daniel J; Xie, Jun; Shirwany, Najeeb; Guo, Qing

    2008-01-01

    Traumatic brain injury (TBI) is a significant clinical problem, yet few effective strategies for treating it have emerged. People that sustain and survive a TBI are left with significant cognitive, behavioral, and communicative disabilities. Apoptotic neuronal death occurs following TBI. Prostate apoptosis response-4 (Par-4) is a death domain-containing protein initially characterized as a critical regulator of apoptosis in prostate cancer cells. We have recently generated and characterized Par-4 transgenic mice in which the expression of the par-4 transgene was limited to cells of neuronal lineage. We now provide evidence that, in cortical neurons from these mice, Par-4 drastically increases apoptotic neuronal death in both in vitro and in vivo models of TBI. In vitro experiments were performed in 7-day-old primary cultures of cortical neurons using a previously published, scratch-induced mechanical trauma model. Neurons that overexpress Par-4 showed not only a significant decrease in overall neuron survival after TBI compared to wild-type cells, but also exhibited a sharper decrease in mitochondrial transmembrane potential, a higher degree of free radical accumulation, and earlier activation of caspase-3 than wild-type cells did. In vivo experiments were performed utilizing a weight drop TBI model. A significantly increased volume of cortical injury and exacerbated activation of caspase-3 were observed in Par-4 transgenic mice when compared to those in wild-type mice. These data suggests that aberrant Par-4 expression exacerbates neuronal cell death following TBI by altering mitochondrial function, enhancing oxidative damage, and execution of apoptosis via caspase activation. PMID:18784822

  17. Protective effect of panaxydol and panaxynol on sodium nitroprusside-induced apoptosis in cortical neurons.

    PubMed

    Nie, Bao-Ming; Yang, Li-Min; Fu, Sai-Li; Jiang, Xiao-Yan; Lu, Pei-Hua; Lu, Yang

    2006-04-15

    An excess of the free radical nitric oxide (NO) is viewed as a deleterious factor involved in various CNS disorders. The protective effect of panaxydol (PND) and panaxynol (PNN) on sodium nitroprusside (SNP)-induced neuronal apoptosis and potential mechanism were investigated in primary cultured rat cortical neurons. Pretreatment of the cells with PND or PNN for 24 h following 1mM SNP, an exogenous NO donor, exposure for 1h, resulted significantly in reduction of cell death induced by SNP determined by MTT assay, LDH release and Hoechst staining. 5 microM PND and PNN also reduced the up-regulation of the pro-apoptotic gene, Bax, down-regulation of the anti-apoptotic gene, Bcl-2. The observations demonstrated that PND and PNN protect neurons against SNP-induced apoptosis via regulating the apoptotic related genes. The results raise the possibility that PND and PNN reduce neurodegeneration in the Alzheimer's brain.

  18. Ezh2 is involved in radial neuronal migration through regulating Reelin expression in cerebral cortex

    PubMed Central

    Zhao, Linnan; Li, Jun; Ma, Yuanlin; Wang, Jiutao; Pan, Wen; Gao, Kai; Zhang, Zhengrong; Lu, Tianlan; Ruan, Yanyan; Yue, Weihua; Zhao, Shanting; Wang, Lifang; Zhang, Dai

    2015-01-01

    Radial migration of pyramidal neurons is an important event during the development of cerebral cortex. Neurons experience series of morphological and directional transitions to get to their final laminar positions. Here we report that the histone methyltransferase enhancer of zest homolog 2 (Ezh2) is involved in the regulation of cortical radial migration. We show that Ezh2 knockdown leads to disturbed neuronal orientation, which results in the impairment of radial migration. Further results reveal that this migration deficiency may be due to the derepression of Reelin transcription in the migrating neurons. Our study provides evidence that epigenetic regulation of Reelin by Ezh2 maintains appropriate Reelin expression pattern to fulfill proper orientation of migrating neurons. PMID:26499080

  19. Tcf4 Controls Neuronal Migration of the Cerebral Cortex through Regulation of Bmp7.

    PubMed

    Chen, Tianda; Wu, Qinwei; Zhang, Yang; Lu, Tianlan; Yue, Weihua; Zhang, Dai

    2016-01-01

    Background: Transcription factor 4 (TCF4) is found to be associated with schizophrenia. TCF4 mutations also cause Pitt-Hopkins Syndrome, a neurodevelopmental disorder associated with severe mental retardation. However, the function of TCF4 during brain development remains unclear. Results: Here, we report that Tcf4 is expressed in the developing cerebral cortex. In utero suppression of Tcf4 arrested neuronal migration, leading to accumulation of ectopic neurons in the intermediate zone. Knockdown of Tcf4 impaired leading process formation. Furthermore, Bone Morphogenetic Protein 7 (Bmp7) is upregulated in Tcf4-deficient neurons. In vivo gain of function and rescue experiments demonstrated that Bmp7 is the major downstream effector of Tcf4 required for neuronal migration. Conclusion: Thus, we have uncovered a new Tcf4/Bmp7-dependent mechanism underlying neuronal migration, and provide insights into the pathogenesis of neurodevelopmental disorders.

  20. Sevoflurane induces endoplasmic reticulum stress mediated apoptosis in hippocampal neurons of aging rats.

    PubMed

    Chen, Gang; Gong, Ming; Yan, Min; Zhang, Xiaoming

    2013-01-01

    Elderly patients are more likely to suffer from postoperative memory impairment for volatile anesthetics could induce aging neurons degeneration and apoptosis while the mechanism was still elusive. Therefore we hypothesized that ER stress mediated hippocampal neurons apoptosis might play an important role in the mechanism of sevoflurane-induced cognitive impairment in aged rats. Thirty 18-month-old male Sprague-Dawley rats were divided into two groups: the sham anesthesia group (exposure to simply humidified 30-50% O2 balanced by N2 in an acrylic anesthetizing chamber for 5 hours) and the sevoflurane anesthesia group (received 2% sevoflurane in the same humidified mixed air in an identical chamber for the same time). Spatial memory of rats was assayed by the Morris water maze test. The ultrastructure of the hippocampus was observed by transmission electron microscopy (TEM). The expressions of C/EBP homologous protein (CHOP) and caspase-12 in the hippocampus were observed by immunohistochemistry and real-time PCR analysis. The apoptosis neurons were also assessed by TUNEL assay. The Morris water maze test showed that sevoflurane anesthesia induced spatial memory impairment in aging rats (P<0.05). The apoptotic neurons were condensed and had clumped chromatin with fragmentation of the nuclear membrane, verifying apoptotic degeneration in the sevoflurane group rats by TEM observation. The expressions of CHOP and caspase-12 increased, and the number of TUNEL positive cells of the hippocampus also increased in the sevoflurane group rats (P<0.05). The present results suggested that the long time exposure of sevoflurane could induce neuronal degeneration and cognitive impairment in aging rats. The ER stress mediated neurons apoptosis may play a role in the sevoflurane-induced memory impairment in aging rats.

  1. Caspase-3 inhibitor prevents the apoptosis of brain tissue in rats with acute cerebral infarction.

    PubMed

    Sun, Yuhua; Xu, Yuming; Geng, Lijiao

    2015-07-01

    The aim of the present study was to investigate the effect of the caspase-3 inhibitor z-DEVD-fmk on the apoptosis of the brain tissues of rats with acute cerebral infarction. Middle cerebral artery occlusion was used to establish a rat model of infarction, and the rats were randomly divided into a sham group (n=15), model group (n=15) and treatment group (n=15). z-DEVD-fmk (2.5 µg/kg) was injected into the intracranial artery of rats in the treatment group, while the same volume of phosphate-buffered saline solution was administered to the rats of the sham and model groups. After 48 h, all rats were sacrificed and their brain tissues were removed. The caspase-3 mRNA level, protein level and activity, brain cell apoptosis index and infarction scope of the three groups were analyzed. Neurological impairment was also assessed. At 48 h after model establishment, the caspase-3 mRNA and protein levels in the brain tissues of the model group were significantly higher than those of the sham group, and those in the treatment group were significantly lower than those in the model group (P<0.05); however, they remained significantly higher than those in the sham group. Caspase-3 activity in the model group was significantly higher than that in the sham group, and treatment with the caspase-3 inhibitor significantly reduced caspase-3 activity compared with that in the model group (P<0.05). The apoptosis index and infarction scope in the model and treatment groups were significantly increased compared with those in the sham group, and were significantly lower in the treatment group than in the model group (P<0.05). The neurological impairment of rats in the model and treatment groups was increased significantly compared with that in the sham group, and the treatment group exhibited a significantly lower level of neurological impairment than the model group (P<0.05). In conclusion, the caspase-3 inhibitor z-DEVD-fmk effectively inhibited apoptosis and delayed the necrosis of

  2. Caspase-3 inhibitor prevents the apoptosis of brain tissue in rats with acute cerebral infarction

    PubMed Central

    SUN, YUHUA; XU, YUMING; GENG, LIJIAO

    2015-01-01

    The aim of the present study was to investigate the effect of the caspase-3 inhibitor z-DEVD-fmk on the apoptosis of the brain tissues of rats with acute cerebral infarction. Middle cerebral artery occlusion was used to establish a rat model of infarction, and the rats were randomly divided into a sham group (n=15), model group (n=15) and treatment group (n=15). z-DEVD-fmk (2.5 µg/kg) was injected into the intracranial artery of rats in the treatment group, while the same volume of phosphate-buffered saline solution was administered to the rats of the sham and model groups. After 48 h, all rats were sacrificed and their brain tissues were removed. The caspase-3 mRNA level, protein level and activity, brain cell apoptosis index and infarction scope of the three groups were analyzed. Neurological impairment was also assessed. At 48 h after model establishment, the caspase-3 mRNA and protein levels in the brain tissues of the model group were significantly higher than those of the sham group, and those in the treatment group were significantly lower than those in the model group (P<0.05); however, they remained significantly higher than those in the sham group. Caspase-3 activity in the model group was significantly higher than that in the sham group, and treatment with the caspase-3 inhibitor significantly reduced caspase-3 activity compared with that in the model group (P<0.05). The apoptosis index and infarction scope in the model and treatment groups were significantly increased compared with those in the sham group, and were significantly lower in the treatment group than in the model group (P<0.05). The neurological impairment of rats in the model and treatment groups was increased significantly compared with that in the sham group, and the treatment group exhibited a significantly lower level of neurological impairment than the model group (P<0.05). In conclusion, the caspase-3 inhibitor z-DEVD-fmk effectively inhibited apoptosis and delayed the necrosis of

  3. Neuroprotection via matrix-trophic coupling between cerebral endothelial cells and neurons.

    PubMed

    Guo, Shuzhen; Kim, Woo Jean; Lok, Josephine; Lee, Sun-Ryung; Besancon, Elaine; Luo, Bing-Hao; Stins, Monique F; Wang, Xiaoying; Dedhar, Shoukat; Lo, Eng H

    2008-05-27

    The neurovascular unit is an emerging concept that emphasizes homeostatic interactions between endothelium and cerebral parenchyma. Here, we show that cerebral endothelium are not just inert tubes for delivering blood, but they also secrete trophic factors that can be directly neuroprotective. Conditioned media from cerebral endothelial cells broadly protects neurons against oxygen-glucose deprivation, oxidative damage, endoplasmic reticulum stress, hypoxia, and amyloid neurotoxicity. This phenomenon is largely mediated by endothelial-produced brain-derived neurotrophic factor (BDNF) because filtering endothelial-conditioned media with TrkB-Fc eliminates the neuroprotective effect. Endothelial production of BDNF is sustained by beta-1 integrin and integrin-linked kinase (ILK) signaling. Noncytotoxic levels of oxidative stress disrupts ILK signaling and reduces endothelial levels of neuroprotective BDNF. These data suggest that cerebral endothelium provides a critical source of homeostatic support for neurons. Targeting these signals of matrix and trophic coupling between endothelium and neurons may provide new therapeutic opportunities for stroke and other CNS disorders.

  4. Progressive Cortical Neuronal Damage and Chronic Hemodynamic Impairment in Atherosclerotic Major Cerebral Artery Disease.

    PubMed

    Yamauchi, Hiroshi; Kagawa, Shinya; Kishibe, Yoshihiko; Takahashi, Masaaki; Higashi, Tatsuya

    2016-06-01

    Cross-sectional studies suggest that chronic hemodynamic impairment may cause selective cortical neuronal damage in patients with atherosclerotic internal carotid artery or middle cerebral artery occlusive disease. The purpose of this longitudinal study was to determine whether the progression of cortical neuronal damage, evaluated as a decrease in central benzodiazepine receptors (BZRs), is associated with hemodynamic impairment at baseline or hemodynamic deterioration during follow-up. We evaluated the distribution of BZRs twice using positron emission tomography and (11)C-flumazenil over time in 80 medically treated patients with atherosclerotic internal carotid artery or middle cerebral artery occlusive disease that had no ischemic episodes during follow-up. Using 3D stereotactic surface projections, we quantified abnormal decreases in the BZRs in the cerebral cortex within the middle cerebral artery distribution and correlated changes in the BZR index with the mean hemispheric values of hemodynamic parameters obtained from (15)O gas positron emission tomography. In the hemisphere affected by arterial disease, the BZR index in 40 patients (50%) was increased during follow-up (mean 26±20 months). In multivariable logistic regression analyses, increases in the BZR index were associated with the decreased cerebral blood flow at baseline and an increased oxygen extraction fraction during follow-up. Increases in the oxygen extraction fraction during follow-up were associated with a lack of statin use. In patients with atherosclerotic internal carotid artery or middle cerebral artery disease, the progression of cortical neuronal damage was associated with hemodynamic impairment at baseline and hemodynamic deterioration during follow-up. Statin use may be beneficial against hemodynamic deterioration and therefore neuroprotective. © 2016 American Heart Association, Inc.

  5. Electron microscopic evidence against apoptosis as the mechanism of neuronal death in global ischemia.

    PubMed

    Colbourne, F; Sutherland, G R; Auer, R N

    1999-06-01

    It has been repeatedly claimed that neuronal death in the hippocampal CA1 sector after untreated global ischemia occurs via apoptosis. This is based largely on DNA laddering, nick end labeling, and light microscopy. Delineation of apoptosis requires fine structural examination to detect morphological events of cell death. We studied the light and ultrastructural characteristics of CA1 injury after 5 min of untreated global ischemia in gerbils. To increase the likelihood of apoptosis, some ischemic gerbils were subjected to delayed postischemic hypothermia, a treatment that mitigates injury and delays the death of some neurons. In these gerbils, 2 d of mild hypothermia was initiated 1, 6, or 12 hr after ischemia, and gerbils were killed 4, 14, or 60 d later. Ischemia without subsequent cooling killed 96% of CA1 neurons by day 4, whereas all hypothermia-treated groups had significantly reduced injury at all survival times (2-67% loss). Electron microscopy of ischemic neurons with or without postischemic hypothermia revealed features of necrotic, not apoptotic, neuronal death even in cells that died 2 months after ischemia. Dilated organelles and intranuclear vacuoles preceded necrosis. Unique to the hypothermia-treated ischemic groups, some salvaged neurons were persistently abnormal and showed accumulation of unusual, morphologically complex secondary lysosomes. These indicate selective mitochondrial injury, because they were closely associated with normal and degenerate mitochondria, and transitional forms between mitochondria and lysosomes occurred. The results show that untreated global ischemic injury has necrotic, not apoptotic, morphology but do not rule out programmed biochemical events of the apoptotic pathway occurring before neuronal necrosis.

  6. Ouabain-Induced Apoptosis in Cochlear Hair Cells and Spiral Ganglion Neurons In Vitro

    PubMed Central

    Fu, Yong; Ding, Dalian; Jiang, Haiyan; Salvi, Richard

    2013-01-01

    Ouabain is a common tool to explore the pathophysiological changes in adult mammalian cochlea in vivo. In prior studies, locally administering ouabain via round window membrane demonstrated that the ototoxic effects of ouabain in vivo varied among mammalian species. Little is known about the ototoxic effects in vitro. Thus, we prepared cochlear organotypic cultures from postnatal day-3 rats and treated these cultures with ouabain at 50, 500, and 1000 μM for different time to elucidate the ototoxic effects of ouabain in vitro and to provide insights that could explain the comparative ototoxic effects of ouabain in vivo. Degeneration of cochlear hair cells and spiral ganglion neurons was evaluated by hair-cell staining and neurofilament labeling, respectively. Annexin V staining was used to detect apoptotic cells. A quantitative RT-PCR apoptosis-focused gene array determined changes in apoptosis-related genes. The results showed that ouabain-induced damage in vitro was dose and time dependent. 500 μM ouabain and 1000 μM ouabain were destructively traumatic to both spiral ganglion neurons and cochlear hair cells in an apoptotic signal-dependent pathway. The major apoptotic pathways in ouabain-induced spiral ganglion neuron apoptosis culminated in the stimulation of the p53 pathway and triggering of apoptosis by a network of proapoptotic signaling pathways. PMID:24228256

  7. Particulate matter (PM2.5) exposure season-dependently induces neuronal apoptosis and synaptic injuries.

    PubMed

    Chen, Minjun; Li, Ben; Sang, Nan

    2017-04-01

    Epidemiological studies have shown that particulate matter 2.5 (PM2.5) not only increases the incidence of cardiopulmonary illnesses but also relates to the development of neurodegenerative diseases. Considering that PM2.5 is highly heterogeneous with regional disparity and seasonal variation, we investigated whether PM2.5 exposure induced neuronal apoptosis and synaptic injuries in a season-dependent manner. The results indicated that PM2.5 altered the expression of apoptosis-related proteins (mainly bax and bcl-2), activated caspase-3 and caused neuronal apoptosis. Additionally, PM2.5 decreased the levels of synaptic structural protein postsynaptic density (PSD-95) and synaptic functional protein N-methyl-D-aspartate (NMDA) receptor subunit (NR2B) expression. These effects occurred in a season-dependent manner, and PM2.5 collected from the winter showed the strongest changes. Furthermore, the effect was coupled with the inhibition of phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) and phosphorylated cAMP-response element binding protein (p-CREB). Based on the findings, we analyzed the correlations between the chemical composition of PM2.5 samples and the biological effects, and confirmed that winter PM2.5 played a major role in causing neuronal apoptosis and synaptic injuries among different season samples. Copyright © 2016. Published by Elsevier B.V.

  8. Histologic assessment of neurons in rat models of cerebral ischemia.

    PubMed

    Eke, A; Conger, K A; Anderson, M; Garcia, J H

    1990-02-01

    We describe a method for typing neurons into four progressive stages of ischemic deterioration based on visual characterization of the nucleus in terms of its optical contrast, delineation along the nuclear-cytoplasmic interface, and its shape. Difficulty in assessing nuclear shape required the introduction of an angularity comparator chart to improve the investigator's accuracy. Three investigators typed neurons obtained from normal, ischemic, and ischemic-reperfused rat brains. Accuracy and reproducibility of the investigators' typing decisions with and without the angularity comparator charts were evaluated. The accuracy of subjective shape assessment was compared with objective digitizer measurements of the same. The angularity comparator charts reduced subjective shape classification error by two thirds, and group error (overall performance expressed by the coefficient of variance) decreased from 15.9% to 4.7% for Type I (normal cells), from 33.9% to 17.3% for Type II (cells with angular nuclei), from 15.5% to 14.1% for Type III (cells with smeared nuclei), and from 3.2% to 5.5% for Type IV (dead cells). Thus, Type I and IV neurons can be assessed at a higher reproducibility than the intermediate Types II and III. Our typing method can also be used to evaluate the effect of treatment regimes on ischemic neuronal damage.

  9. Neuronal damage and calcium accumulation following transient cerebral ischemia in the rat

    SciTech Connect

    Araki, T.; Inoue, T.; Kato, H.; Kogure, K.; Murakami, M. )

    1990-06-01

    The purpose of this study was to examine the distribution of neuronal damage following transient cerebral ischemia in the rat model of four-vessel occlusion utilizing light microscopy as well as {sup 45}Ca-autoradiography. Transient ischemia was induced for 30 min. The animals were allowed to survive for 7 d after ischemia. In the animals subjected to ischemia, the most frequently and seriously damaged areas were the paramedian region of hippocampus, the hippocampal CA1 sector, and the dorsolateral part of striatum, followed by the inferior colliculus, the substantia nigra, the frontal cortex, and the thalamus, which were moderate damaged. Furthermore, the cerebellar Purkinje neurons, the hippocampal CA4 sector, the medial geniculate body, and the hippocampal CA3 sector were slightly affected. {sup 45}Ca-autoradiographyic study also revealed calcium accumulation in the identical sites of ischemic neuronal damage, except for the frontal cortex. Regional cerebral blood flow during 10 min of ischemia was severely decreased in selectively vulnerable areas. The blood flow in the medial geniculate body, the substantia nigra, the inferior colliculus, and the cerebellum was less pronounced than that in the selectively vulnerable areas. The present study demonstrates that transient cerebral ischemia can produce significant neuronal damage not only in the selectively vulnerable regions, but also in the brainstem.

  10. Consistent delayed unilateral neuronal death after modified transient focal cerebral ischemia in mice that mimics neuronal injury after transient global cerebral ischemia.

    PubMed

    Nishijima, Yasuo; Niizuma, Kuniyasu; Fujimura, Miki; Akamatsu, Yosuke; Shimizu, Hiroaki; Tominaga, Teiji

    2015-07-01

    Numerous studies have attempted to reveal the pathophysiology of ischemic neuronal injury using a representative transient global cerebral ischemia (tGCI) model in rodents; however, most of them have used gerbil or rat models. Recent advances in transgene and gene-knockout technology have enabled the precise molecular mechanisms of ischemic brain injury to be investigated. Because the predominant species for the study of genetic mutations is the mouse, a representative mouse model of tGCI is of particular importance. However, simple mouse models of tGCI are less reproducible; therefore, a more complex process or longer duration of ischemia, which causes a high mortality rate, has been used in previous tGCI models in mice. In this study, the authors aimed to overcome these problems and attempted to produce consistent unilateral delayed hippocampal CA1 neuronal death in mice. C57BL/6 mice were subjected to short-term unilateral cerebral ischemia using a 4-mm silicone-coated intraluminal suture to obstruct the origin of the posterior cerebral artery (PCA), and regional cerebral blood flow (rCBF) of the PCA territory was measured using laser speckle flowmetry. The mice were randomly assigned to groups of different ischemic durations and histologically evaluated at different time points after ischemia. The survival rate and neurological score of the group that experienced 15 minutes of ischemia were also evaluated. Consistent neuronal death was observed in the medial CA1 subregion 4 days after 15 minutes of ischemia in the group of mice with a reduction in rCBF of < 65% in the PCA territory during ischemia. Morphologically degenerated cells were mostly positive for terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling and cleaved caspase 3 staining 4 days after ischemia. The survival rates of the mice 24 hours (n = 24), 4 days (n = 15), and 7 days (n = 7) after being subjected to 15 minutes of ischemia were 95.8%, 100%, and 100

  11. Identification of prothymosin-α1, the necrosis–apoptosis switch molecule in cortical neuronal cultures

    PubMed Central

    Ueda, Hiroshi; Fujita, Ryousuke; Yoshida, Akira; Matsunaga, Hayato; Ueda, Mutsumi

    2007-01-01

    We initially identified a nuclear protein, prothymosin-α1 (ProTα), as a key protein inhibiting necrosis by subjecting conditioned media from serum-free cultures of cortical neurons to a few chromatography steps. ProTα inhibited necrosis of cultured neurons by preventing rapid loss of cellular adenosine triphosphate levels by reversing the decreased membrane localization of glucose transporters but caused apoptosis through up-regulation of proapoptotic Bcl2-family proteins. The apoptosis caused by ProTα was further inhibited by growth factors, including brain-derived neurotrophic factor. The ProTα-induced cell death mode switch from necrosis to apoptosis was also reproduced in experimental ischemia-reperfusion culture experiments, although the apoptosis level was markedly reduced, possibly because of the presence of growth factors in the reperfused serum. Knock down of PKCβII expression prevented this cell death mode switch. Collectively, these results suggest that ProTα is an extracellular signal protein that acts as a cell death mode switch and could be a promising candidate for preventing brain strokes with the help of known apoptosis inhibitors. PMID:17353361

  12. Inhibition of apoptosis in neuronal cells infected with Chlamydophila (Chlamydia) pneumoniae.

    PubMed

    Appelt, Denah M; Roupas, Maria R; Way, Deana S; Bell, Marcus G; Albert, Elizabeth V; Hammond, Christine J; Balin, Brian J

    2008-01-24

    Chlamydophila (Chlamydia) pneumoniae is an intracellular bacterium that has been identified within cells in areas of neuropathology found in Alzheimer disease (AD), including endothelia, glia, and neurons. Depending on the cell type of the host, infection by C. pneumoniae has been shown to influence apoptotic pathways in both pro- and anti-apoptotic fashions. We have hypothesized that persistent chlamydial infection of neurons may be an important mediator of the characteristic neuropathology observed in AD brains. Chronic and/or persistent infection of neuronal cells with C. pneumoniae in the AD brain may affect apoptosis in cells containing chlamydial inclusions. SK-N-MC neuroblastoma cells were infected with the respiratory strain of C. pneumoniae, AR39 at an MOI of 1. Following infection, the cells were either untreated or treated with staurosporine and then examined for apoptosis by labeling for nuclear fragmentation, caspase activity, and membrane inversion as indicated by annexin V staining. C. pneumoniae infection was maintained through 10 days post-infection. At 3 and 10 days post-infection, the infected cell cultures appeared to inhibit or were resistant to the apoptotic process when induced by staurosporine. This inhibition was demonstrated quantitatively by nuclear profile counts and caspase 3/7 activity measurements. These data suggest that C. pneumoniae can sustain a chronic infection in neuronal cells by interfering with apoptosis, which may contribute to chronic inflammation in the AD brain.

  13. Inhibition of apoptosis in neuronal cells infected with Chlamydophila (Chlamydia) pneumoniae

    PubMed Central

    Appelt, Denah M; Roupas, Maria R; Way, Deana S; Bell, Marcus G; Albert, Elizabeth V; Hammond, Christine J; Balin, Brian J

    2008-01-01

    Background Chlamydophila (Chlamydia) pneumoniae is an intracellular bacterium that has been identified within cells in areas of neuropathology found in Alzheimer disease (AD), including endothelia, glia, and neurons. Depending on the cell type of the host, infection by C. pneumoniae has been shown to influence apoptotic pathways in both pro- and anti-apoptotic fashions. We have hypothesized that persistent chlamydial infection of neurons may be an important mediator of the characteristic neuropathology observed in AD brains. Chronic and/or persistent infection of neuronal cells with C. pneumoniae in the AD brain may affect apoptosis in cells containing chlamydial inclusions. Results SK-N-MC neuroblastoma cells were infected with the respiratory strain of C. pneumoniae, AR39 at an MOI of 1. Following infection, the cells were either untreated or treated with staurosporine and then examined for apoptosis by labeling for nuclear fragmentation, caspase activity, and membrane inversion as indicated by annexin V staining. C. pneumoniae infection was maintained through 10 days post-infection. At 3 and 10 days post-infection, the infected cell cultures appeared to inhibit or were resistant to the apoptotic process when induced by staurosporine. This inhibition was demonstrated quantitatively by nuclear profile counts and caspase 3/7 activity measurements. Conclusion These data suggest that C. pneumoniae can sustain a chronic infection in neuronal cells by interfering with apoptosis, which may contribute to chronic inflammation in the AD brain. PMID:18218130

  14. Soluble cpg15 from Astrocytes Ameliorates Neurite Outgrowth Recovery of Hippocampal Neurons after Mouse Cerebral Ischemia.

    PubMed

    Zhao, Jing-Jing; Hu, Jie-Xian; Lu, De-Xin; Ji, Chun-Xia; Qi, Yao; Liu, Xiao-Yan; Sun, Feng-Yan; Huang, Fang; Xu, Ping; Chen, Xian-Hua

    2017-02-08

    The present study focuses on the function of cpg15, a neurotrophic factor, in ischemic neuronal recovery using transient global cerebral ischemic (TGI) mouse model and oxygen-glucose deprivation (OGD)-treated primary cultured cells. The results showed that expression of cpg15 proteins in astrocytes, predominantly the soluble form, was significantly increased in mouse hippocampus after TGI and in the cultured astrocytes after OGD. Addition of the medium from the cpg15-overexpressed astrocytic culture into the OGD-treated hippocampal neuronal cultures reduces the neuronal injury, whereas the recovery of neurite outgrowths of OGD-injured neurons was prevented when cpg15 in the OGD-treated astrocytes was knocked down, or the OGD-treated-astrocytic medium was immunoadsorbed by cpg15 antibody. Furthermore, lentivirus-delivered knockdown of cpg15 expression in mouse hippocampal astrocytes diminishes the dendritic branches and exacerbates injury of neurons in CA1 region after TGI. In addition, treatment with inhibitors of MEK1/2, PI3K, and TrkA decreases, whereas overexpression of p-CREB, but not dp-CREB, increases the expression of cpg15 in U118 or primary cultured astrocytes. Also, it is observed that the Flag-tagged soluble cpg15 from the astrocytes transfected with Flag-tagged cpg15-expressing plasmids adheres to the surface of neuronal bodies and the neurites. In conclusion, our results suggest that the soluble cpg15 from astrocytes induced by ischemia could ameliorate the recovery of the ischemic-injured hippocampal neurons via adhering to the surface of neurons. The upregulated expression of cpg15 in astrocytes may be activated via MAPK and PI3K signal pathways, and regulation of CREB phosphorylation.SIGNIFICANCE STATEMENT Neuronal plasticity plays a crucial role in the amelioration of neurological recovery of ischemic injured brain, which remains a challenge for clinic treatment of cerebral ischemia. cpg15 as a synaptic plasticity-related factor may participate in

  15. Effect of prenatal exposure to ethanol on the development of cerebral cortex: I. Neuronal generation

    SciTech Connect

    Miller, M.W.

    1988-06-01

    Prenatal exposure to ethanol causes profound disruptions in the development of the cerebral cortex. Therefore, the effect of in utero ethanol exposure on the generation of neurons was determined. Pregnant rats were fed a liquid diet in which ethanol constituted 37.5% of the total caloric content (Et) or pair-fed an isocaloric control diet (Ct) from gestational day (GD) 6 to the day of birth. The time of origin of cortical neurons was determined in the mature pups of females injected with (3H)thymidine on one day during the period from GD 10 to the day of birth. The brains were processed by standard autoradiographic techniques. Ethanol exposure produced multiple defects in neuronal ontogeny. The period of generation was 1-2 days later for Et-treated rats than for rats exposed prenatally to either control diet. Moreover, the generation period was 1-2 days longer in Et-treated rats. The numbers of neurons generated on a specific day was altered; from GD 12-19 significantly fewer neurons were generated in Et-treated rats than in Ct-treated rats, whereas after GD 19 more neurons were born. The distribution of neurons generated on a specific day was disrupted; most notable was the distribution of late-generated neurons in deep cortex of Et-treated rats rather than in superficial cortex as they are in controls. Cortical neurons in Et-treated rats tended to be smaller than in Ct-treated rats, particularly early generated neurons in deep cortex. The late-generated neurons in Et-treated rats were of similar size to those in Ct-treated rats despite their abnormal position in deep cortex. Neurons in Ct-treated rats tended to be rounder than those in Et-treated rats which were more polarized in the radial orientation.

  16. Alcohol-induced apoptosis of canine cerebral vascular smooth muscle cells: role of extracellular and intracellular calcium ions.

    PubMed

    Li, Wenyan; Li, Jianfeng; Liu, Weiming; Altura, Bella T; Altura, Burton M

    2004-01-16

    Exposure of canine cerebral vascular smooth muscle cells (VSMCs) to ethanol (10, 25 and 100 mM) for 1, 3 and 5 days induced apoptosis with its typical characteristics of nuclear shrinkage, condensation, and DNA breakage as well as formation of apoptotic bodies observed by fluorescence staining, terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling and comet assays. Such effects of alcohol on cerebral VSMCs were time- and concentration-dependent. The threshold ethanol concentration for induction of the apoptotic process was found to be 10 mM. Extracellular and intracellular Ca2+ chelators, i.e. ethylglycol-bisbeta-aminoethylether-N,N,N'N'-tetraacetic acid (EGTA, 5 mM) and 1,2-bis(2-aminophenoxy)-ethane-N,N,N',N'-tetra-acetic acid AM (BAPTA, 10(-6) M), respectively, ameliorated greatly the number of cerebral VSMCs which underwent apoptosis. Verapamil, however, failed to inhibit apoptosis of cerebral VSMCs. From these new findings, we suggest that alcohol-induced apoptosis may contribute to alcohol-induced brain-vascular damage and stroke. In addition, our findings point to potential caution for humans who imbibe two or more standard drinks per day or who undergo 'binge drinking'.

  17. Evidence of parvovirus replication in cerebral neurons of cats.

    PubMed

    Url, Angelika; Truyen, Uwe; Rebel-Bauder, Barbara; Weissenböck, Herbert; Schmidt, Peter

    2003-08-01

    The correlation between parvovirus infections and lesions in the central nervous system other than cerebellar hypoplasia was studied in 100 cats. The animals were necropsied with a history of various diseases, one third showing typical clinical and pathomorphological signs of panleukopenia. In 18 cats polyclonal antiserum against canine parvovirus consistently labeled neurons mainly in diencephalic regions, whereas the cerebellar cortex remained negative in all cases. In situ hybridization with digoxigenin-labeled minus-sense RNA probes, hybridizing with monomer-replicative form DNA or mRNA, revealed positive signals in nuclei of several neurons of the brain, again excluding the cerebellum. PCR applied to formalin-fixed and paraffin-embedded brain tissue and intestinal tissues of the diseased cats and subsequent DNA sequence analysis yielded canine parvovirus type 2 (CPV-2)-like sequences in the central nervous system. Two aspects of these findings are intriguing: (i). parvoviruses appear to be capable of replicating in neurons, cells that are considered to be terminally differentiated and (ii). CPV-like viruses of the old antigenic type CPV-2 appear to be able to infect cats.

  18. Cerebral neurons underlying prey capture movements in the pteropod mollusc, Clione limacina. II. Afterdischarges.

    PubMed

    Norekian, T P

    1993-03-01

    The pteropod mollusc Clione limacina is a highly specialized carnivore which feeds on shelled pteropods and uses, for their capture, three pairs of oral appendages, called buccal cones. Contact with the prey induces rapid eversion of buccal cones, which then become tentacle-like and grasp the shell of the prey. In the previous paper, a large group of electrically coupled, normally silent cells (A motoneurons) has been described in the cerebral ganglia of Clione. Activation of A neurons induces opening of oral skin folds and extrusion of the buccal cones. The present study continues the analysis of the electrical properties of A motoneurons. Brief intracellular stimulation of an A neuron can produce prolonged firing (afterdischarge), lasting up to 40 s, in the entire population of A neurons. After-discharge activity is based on an afterdepolarization evoked by an initial strong burst of A neuron spikes. The data suggest that this afterdepolarization represents excitatory synaptic input from unidentified neurons which in turn receive excitatory inputs from A neurons, thus organizing positive feedback. The main functional role of this positive feedback is the spread and synchronization of spike activity among all A neurons in the population. In addition, it serves to transform a brief excitatory input to A neurons into their prolonged and stable firing, which is required during certain phases of feeding behavior in Clione.

  19. Foxp1 Regulates Cortical Radial Migration and Neuronal Morphogenesis in Developing Cerebral Cortex

    PubMed Central

    Li, Xue; Xiao, Jian; Fröhlich, Henning; Tu, Xiaomeng; Li, Lianlian; Xu, Yue; Cao, Huateng; Qu, Jia; Rappold, Gudrun A.; Chen, Jie-Guang

    2015-01-01

    FOXP1 is a member of FOXP subfamily transcription factors. Mutations in FOXP1 gene have been found in various development-related cognitive disorders. However, little is known about the etiology of these symptoms, and specifically the function of FOXP1 in neuronal development. Here, we report that suppression of Foxp1 expression in mouse cerebral cortex led to a neuronal migration defect, which was rescued by overexpression of Foxp1. Mice with Foxp1 knockdown exhibited ectopic neurons in deep layers of the cortex postnatally. The neuronal differentiation of Foxp1-downregulated cells was normal. However, morphological analysis showed that the neurons with Foxp1 deficiency had an inhibited axonal growth in vitro and a weakened transition from multipolar to bipolar in vivo. Moreover, we found that the expression of Foxp1 modulated the dendritic maturation of neurons at a late postnatal date. Our results demonstrate critical roles of Foxp1 in the radial migration and morphogenesis of cortical neurons during development. This study may shed light on the complex relationship between neuronal development and the related cognitive disorders. PMID:26010426

  20. Astrocytes Prevent Ethanol Induced Apoptosis of Nrf2 Depleted Neurons by Maintaining GSH Homeostasis

    PubMed Central

    Narasimhan, Madhusudhanan; Rathinam, Marylatha; Patel, Dhyanesh; Henderson, George; Mahimainathan, Lenin

    2013-01-01

    Glutathione (GSH), a major cellular antioxidant protects cells against oxidative stress injury. Nuclear factor erythroid 2-related factor 2 (NFE2L2/Nrf2) is a redox sensitive master regulator of battery of antioxidant enzymes including those involved in GSH antioxidant machinery. Earlier we reported that ethanol (ETOH) elicits apoptotic death of primary cortical neurons (PCNs) which in partly due to depletion of intracellular GSH levels. Further a recent report from our laboratory illustrated that ETOH exacerbated the dysregulation of GSH and caspase mediated cell death of cortical neurons that are compromised in Nrf2 machinery (Narasimhan et al., 2011). In various experimental models of neurodegeneration, neuronal antioxidant defenses mainly GSH has been shown to be supported by astrocytes. We therefore sought to determine whether astrocytes can render protection to neurons against ETOH toxicity, particularly when the function of Nrf2 is compromised in neurons. The experimental model consisted of co-culturing primary cortical astrocytes (PCA) with Nrf2 downregulated PCNs that were exposed with 4 mg/mL ETOH for 24 h. Monochlorobimane (MCB) staining followed by FACS analysis showed that astrocytes blocked ETOH induced GSH decrement in Nrf2-silenced neurons as opposed to exaggerated GSH depletion in Nrf2 downregulated PCNs alone. Similarly, the heightened activation of caspase 3/7 observed in Nrf2-compromised neurons was attenuated when co-cultured with astrocytes as measured by luminescence based caspase Glo assay. Furthermore, annexin-V-FITC staining followed by FACS analysis revealed that Nrf2 depleted neurons showed resistance to ETOH induced neuronal apoptosis when co-cultured with astrocytes. Thus, the current study identifies ETOH induced dysregulation of GSH and associated apoptotic events observed in Nrf2-depleted neurons can be blocked by astrocytes. Further our results suggest that this neuroprotective effect of astrocyte despite dysfunctional Nrf2 system

  1. Astrocytes Prevent Ethanol Induced Apoptosis of Nrf2 Depleted Neurons by Maintaining GSH Homeostasis.

    PubMed

    Narasimhan, Madhusudhanan; Rathinam, Marylatha; Patel, Dhyanesh; Henderson, George; Mahimainathan, Lenin

    2012-07-01

    Glutathione (GSH), a major cellular antioxidant protects cells against oxidative stress injury. Nuclear factor erythroid 2-related factor 2 (NFE2L2/Nrf2) is a redox sensitive master regulator of battery of antioxidant enzymes including those involved in GSH antioxidant machinery. Earlier we reported that ethanol (ETOH) elicits apoptotic death of primary cortical neurons (PCNs) which in partly due to depletion of intracellular GSH levels. Further a recent report from our laboratory illustrated that ETOH exacerbated the dysregulation of GSH and caspase mediated cell death of cortical neurons that are compromised in Nrf2 machinery (Narasimhan et al., 2011). In various experimental models of neurodegeneration, neuronal antioxidant defenses mainly GSH has been shown to be supported by astrocytes. We therefore sought to determine whether astrocytes can render protection to neurons against ETOH toxicity, particularly when the function of Nrf2 is compromised in neurons. The experimental model consisted of co-culturing primary cortical astrocytes (PCA) with Nrf2 downregulated PCNs that were exposed with 4 mg/mL ETOH for 24 h. Monochlorobimane (MCB) staining followed by FACS analysis showed that astrocytes blocked ETOH induced GSH decrement in Nrf2-silenced neurons as opposed to exaggerated GSH depletion in Nrf2 downregulated PCNs alone. Similarly, the heightened activation of caspase 3/7 observed in Nrf2-compromised neurons was attenuated when co-cultured with astrocytes as measured by luminescence based caspase Glo assay. Furthermore, annexin-V-FITC staining followed by FACS analysis revealed that Nrf2 depleted neurons showed resistance to ETOH induced neuronal apoptosis when co-cultured with astrocytes. Thus, the current study identifies ETOH induced dysregulation of GSH and associated apoptotic events observed in Nrf2-depleted neurons can be blocked by astrocytes. Further our results suggest that this neuroprotective effect of astrocyte despite dysfunctional Nrf2 system

  2. [Protective effect of musk extract on rat's cerebral cortical neurons with inflammatory injury].

    PubMed

    Shi, Jin-Feng; Zhang, Bo-Ai; Jia, Yan-Jie

    2010-06-01

    To investigate the protective effects of musk extract (ME) and its possible mechanism on rat's cerebral cortical neurons with inflammatory injury induced by lipopolysaccharide (LPS). Neurons and astrocytes from newborn rat cerebral cortex were cultured in vitro respectively, and the astrocyte conditioned medium (ACM), obtained by treating astrocytes with 10 mg/L LPS and different concentrations of ME for 24 h, was added in the culture fluid of neurons. The survival rate and apoptotic rate of neurons were measured by MTT method and AO/EB stain; and the changes of inflammatory factors in the ACM were determined by ELISA. The survival rate (%) of neurons treated by ACM with ME in concentrations of 18 mg/L, 36 mg/L, 72 mg/L and 144 mg/L was 52.55 +/- 3.52, 55.77 +/- 2.36, 64.89 +/- 3.45 and 73.67 +/- 1.80, respectively, significantly higher than that in the model neurons (43.62 +/- 4. 51, P < 0.05), while the apoptotic rate (%) in them, 68.11 +/- 2.16, 44.27 +/- 3.68, 32.56 +/- 2.14 and 21.89 +/- 2.46, respectively, was significantly lower than that in model neurons (71.33 +/- 3.25, P < 0.05 or P < 0.01). Level of IL-6 was decreasing along with the raising of ME concentration in the ACM, showing a concentration-dependent state. ME shows apparent protective effect on neurons against inflammatory injury, especially in a high concentration (144 mg/L), which may be associated with the reduction of IL-6 secreted by astrocytes.

  3. Transient Enhancement of Inhibitory Synaptic Transmission in Hippocampal CA1 Pyramidal Neurons after Cerebral Ischemia

    PubMed Central

    Liang, Rui; Pang, Zhi-Ping; Deng, Ping; Xu, Zao C.

    2009-01-01

    Pyramidal neurons in hippocampal CA1 regions are highly sensitive to cerebral ischemia. Alterations of excitatory and inhibitory synaptic transmission may contribute to the ischemia-induced neuronal degeneration. However, little is known about the changes of GABAergic synaptic transmission in the hippocampus following reperfusion. We examined the GABAA receptor-mediated inhibitory postsynaptic currents (IPSCs) in CA1 pyramidal neurons 12 hours and 24 hours after transient forebrain ischemia. The amplitudes of evoked IPSCs (eIPSCs) were increased significantly 12 hours after ischemia and returned to control levels 24 hours following reperfusion. The potentiation of eIPSCs was accompanied by an increase of miniature IPSCs (mIPSCs) amplitude, and an enhanced response to exogenous application of GABA, indicating the involvement of postsynaptic mechanisms. Furthermore, there was no obvious change of the paired-pulse ratio (PPR) of eIPSCs and the frequency of mIPSCs, suggesting that the potentiation of eIPSCs might not be due to the increased presynaptic release. Blockade of adenosine A1 receptors led to a decrease of eIPSCs amplitude in post-ischemic neurons but not in control neurons, without affecting the frequency of mIPSCs and the PPR of eIPSCs. Thus, tonic activation of adenosine A1 receptors might, at least in part, contribute to the enhancement of inhibitory synaptic transmission in CA1 neurons after forebrain ischemia. The transient enhancement of inhibitory neurotransmission might temporarily protect CA1 pyramidal neurons, and delay the process of neuronal death after cerebral ischemia. PMID:19258028

  4. Endoplasmic reticulum stress-mediated hippocampal neuron apoptosis involved in diabetic cognitive impairment.

    PubMed

    Zhang, Xiaoming; Xu, Linhao; He, Daqiang; Ling, Shucai

    2013-01-01

    Poor management of DM causes cognitive impairment while the mechanism is still unconfirmed. The aim of the present study was to investigate the activation of C/EBP Homology Protein (CHOP), the prominent mediator of the endoplasmic reticulum (ER) stress-induced apoptosis under hyperglycemia. We employed streptozotocin- (STZ-) induced diabetic rats to explore the ability of learning and memory by the Morris water maze test. The ultrastructure of hippocampus in diabetic rats and cultured neurons in high glucose medium were observed by transmission electron microscopy and scanning electron microscopy. TUNEL staining was also performed to assess apoptotic cells while the expression of CHOP was assayed by immunohistochemistry and Western blot assay in these hippocampal neurons. Six weeks after diabetes induction, the escape latency increased and the average frequency in finding the platform decreased in diabetic rats (P < 0.05). The morphology of neuron and synaptic structure was impaired; the number of TUNEL-positive cells and the expression of CHOP in hippocampus of diabetic rats and high glucose medium cultured neurons were markedly altered (P < 0.05). The present results suggested that the CHOP-dependent endoplasmic reticulum (ER) stress-mediated apoptosis may be involved in hyperglycemia-induced hippocampal synapses and neurons impairment and promote the diabetic cognitive impairment.

  5. Cdk5 is required for multipolar-to-bipolar transition during radial neuronal migration and proper dendrite development of pyramidal neurons in the cerebral cortex.

    PubMed

    Ohshima, Toshio; Hirasawa, Motoyuki; Tabata, Hidenori; Mutoh, Tetsuji; Adachi, Tomoko; Suzuki, Hiromi; Saruta, Keiko; Iwasato, Takuji; Itohara, Shigeyoshi; Hashimoto, Mistuhiro; Nakajima, Kazunori; Ogawa, Masaharu; Kulkarni, Ashok B; Mikoshiba, Katsuhiko

    2007-06-01

    The mammalian cerebral cortex consists of six layers that are generated via coordinated neuronal migration during the embryonic period. Recent studies identified specific phases of radial migration of cortical neurons. After the final division, neurons transform from a multipolar to a bipolar shape within the subventricular zone-intermediate zone (SVZ-IZ) and then migrate along radial glial fibres. Mice lacking Cdk5 exhibit abnormal corticogenesis owing to neuronal migration defects. When we introduced GFP into migrating neurons at E14.5 by in utero electroporation, we observed migrating neurons in wild-type but not in Cdk5(-/-) embryos after 3-4 days. Introduction of the dominant-negative form of Cdk5 into the wild-type migrating neurons confirmed specific impairment of the multipolar-to-bipolar transition within the SVZ-IZ in a cell-autonomous manner. Cortex-specific Cdk5 conditional knockout mice showed inverted layering of the cerebral cortex and the layer V and callosal neurons, but not layer VI neurons, had severely impaired dendritic morphology. The amount of the dendritic protein Map2 was decreased in the cerebral cortex of Cdk5-deficient mice, and the axonal trajectory of cortical neurons within the cortex was also abnormal. These results indicate that Cdk5 is required for proper multipolar-to-bipolar transition, and a deficiency of Cdk5 results in abnormal morphology of pyramidal neurons. In addition, proper radial neuronal migration generates an inside-out pattern of cerebral cortex formation and normal axonal trajectories of cortical pyramidal neurons.

  6. SARM1, not MyD88, mediates TLR7/TLR9-induced apoptosis in neurons1

    PubMed Central

    Mukherjee, Piyali; Winkler, Clayton W.; Taylor, Katherine G.; Woods, Tyson A.; Nair, Vinod; Khan, Burhan A.; Peterson, Karin E.

    2015-01-01

    Neuronal apoptosis is a key aspect of many different neurological diseases, but the mechanisms remain unresolved. Recent studies have suggested a mechanism of innate immune-induced neuronal apoptosis that may act through the stimulation of toll-like receptors (TLR) in neurons. TLRs are stimulated both by pathogen associated molecular patterns (PAMPs) as well as by damage-associated molecular patterns (DAMPs), including micro-RNAs released by damaged neurons. In the current study, we identified the mechanism responsible for TLR7/TLR9-mediated neuronal apoptosis. TLR-induced apoptosis required endosomal localization of TLRs but was independent of MyD88 signaling. Instead, apoptosis required the TLR adaptor molecule, sterile alpha armadillo motif (SARM1), which localized to the mitochondria following TLR activation and was associated with mitochondrial accumulation in neurites. Deficiency in SARM1 inhibited both mitochondrial accumulation in neurites and TLR-induced apoptosis. These studies identify a non-MyD88 pathway of TLR7/TLR9 signaling in neurons and provide a mechanism for how innate immune responses in the CNS directly induce neuronal damage. PMID:26423149

  7. Galanin Protects from Caspase-8/12-initiated Neuronal Apoptosis in the Ischemic Mouse Brain via GalR1

    PubMed Central

    Li, Yun; Mei, Zhu; Liu, Shuiqiao; Wang, Tong; Li, Hui; Li, Xiao-Xiao; Han, Song; Yang, Yutao; Li, Junfa; Xu, Zhi-Qing David

    2017-01-01

    Galanin (GAL) plays key role in many pathophysiological processes, but its role in ischemic stroke remains unclear. Here, the models of 1 h middle cerebral artery occlusion (MCAO)/1-7 d reperfusion (R)-induced ischemic stroke and in vitro cell ischemia of 1 h oxygen-glucose deprivation (OGD)/24 h reoxygenation in primary cultured cortical neurons were used to explore GAL’s effects and its underlying mechanisms. The results showed significant increases of GAL protein levels in the peri-infarct region (P) and infarct core (I) within 48 h R of MCAO mice (p<0.001). The RT-qPCR results also demonstrated significant increases of GAL mRNA during 24-48 h R (p<0.001), and GAL receptors GalR1-2 (but not 3) mRNA levels in the P region at 24 h R of MCAO mice (p<0.001). Furthermore, the significant decrease of infarct volume (p<0.05) and improved neurological outcome (p<0.001-0.05) were observed in MCAO mice following 1 h pre- or 6 h post-treatment of GAL during 1-7 d reperfusion. GalR1 was confirmed as the receptor responsible for GAL-induced neuroprotection by using GalR2/3 agonist AR-M1896 and Lentivirus-based RNAi knockdown of GalR1. GAL treatment inhibited Caspase-3 activation through the upstream initiators Capsases-8/-12 (not Caspase-9) in both P region and OGD-treated cortical neurons. Meanwhile, GAL’s neuroprotective effect was not observed in cortical neurons from conventional protein kinase C (cPKC) γ knockout mice. These results suggested that exogenous GAL protects the brain from ischemic injury by inhibiting Capsase-8/12-initiated apoptosis, possibly mediated by GalR1 via the cPKCγ signaling pathway. PMID:28203483

  8. Clinacanthus nutans Mitigates Neuronal Apoptosis and Ischemic Brain Damage Through Augmenting the C/EBPβ-Driven PPAR-γ Transcription.

    PubMed

    Wu, Jui-Sheng; Kao, Mei-Han; Tsai, Hsin-Da; Cheung, Wai-Mui; Chen, Jin-Jer; Ong, Wei-Yi; Sun, Grace Y; Lin, Teng-Nan

    2017-09-23

    Clinacanthus nutans Lindau (C. nutans) is a traditional herbal medicine widely used in Asian countries for treating a number of remedies including snake and insect bites, skin rashes, viral infections, and cancer. However, the underlying molecular mechanisms for its action and whether C. nutans can offer protection on stroke damage in brain remain largely unknown. In the present study, we demonstrated protective effects of C. nutans extract to ameliorate neuronal apoptotic death in the oxygen-glucose deprivation model and to reduce infarction and mitigate functional deficits in the middle cerebral artery occlusion model, either administered before or after hypoxic/ischemic insult. Using pharmacological antagonist and siRNA knockdown approaches, we demonstrated ability for C. nutans extract to protect neurons and ameliorate ischemic injury through promoting the anti-apoptotic activity of peroxisome proliferator-activated receptor-gamma (PPAR-γ), a stress-induced transcription factor. Reporter and chromatin immunoprecipitation promoter analysis further revealed C. nutans extract to selectively increase CCAAT/enhancer binding protein (C/EBP)β binding to specific C/EBP binding site (-332~-325) on the PPAR-γ promoter to augment its transcription. In summary, we report a novel transcriptional activation involving C/EBPβ upregulation of PPAR-γ expression to suppress ischemic neuronal apoptosis and brain infarct. Recognition of C. nutans to enhance the C/EBPβ → PPAR-γ neuroprotective signaling pathway paves a new way for future drug development for prevention and treatment of ischemic stroke and other neurodegenerative diseases.

  9. The Mitochondrial Permeability Transition Pore Regulates Nitric Oxide-Mediated Apoptosis of Neurons Induced by Target Deprivation

    PubMed Central

    Martin, Lee J.; Adams, Neal A.; Pan, Yan; Price, Ann; Wong, Margaret

    2011-01-01

    Ablation of mouse occipital cortex induces precisely timed and uniform p53-modulated and Bax-dependent apoptosis of thalamocortical projection neurons in the dorsal lateral geniculate nucleus (LGN) by 7 days postlesion. We tested the hypothesis that this neuronal apoptosis is initiated by oxidative stress and the mitochondrial permeability transition pore (mPTP). Pre-apoptotic LGN neurons accumulate mitochondria, Zn2+ and Ca2+, and generate higher levels of reactive oxygen species (ROS), including superoxide, nitric oxide (NO) and peroxynitrite, than LGN neurons with an intact cortical target. Pre-apoptosis of LGN neurons is associated with increased formation of protein carbonyls, protein nitration, and protein S-nitrosylation. Genetic deletion of nitric oxide synthase 1 (nos1) and inhibition of NOS1 with nitroindazole protected LGN neurons from apoptosis, revealing NO as a mediator. Putative components of the mPTP are expressed in mouse LGN, including the voltage-dependent anion channel (VDAC), adenine nucleotide translocator (ANT), and cyclophilin D (CyPD). Nitration of CyPD and ANT in LGN mitochondria occurs by 2 days after cortical injury. Chemical cross-linking showed that LGN neuron pre-apoptosis is associated with formation of CyPD and VDAC oligomers, consistent with mPTP formation. Mice without CyPD are rescued from neuron apoptosis as are mice treated with the mPTP inhibitors TRO-19622 and TAT-Bcl-XL-BH4. Manipulation of the mPTP markedly attenuated the early pre-apoptotic production of reactive oxygen/nitrogen species in target-deprived neurons. Our results demonstrate in adult mouse brain neurons that the mPTP functions to enhance ROS production and the mPTP and NO trigger apoptosis; thus, the mPTP is a target for neuroprotection in vivo. PMID:21209222

  10. Persistent neuronal apoptosis and synaptic loss induced by multiple but not single exposure of propofol contribute to long-term cognitive dysfunction in neonatal rats.

    PubMed

    Chen, Bo; Deng, Xiaoyuan; Wang, Bin; Liu, Hongliang

    2016-01-01

    Propofol can induce acute neuronal apoptosis or long-term cognitive dysfunction when exposed at early age in rodents, but it is unclear how the neurotoxicity including neuronal apoptosis and synaptic loss will change in a dynamic manner with brain development after multiple or single exposure of propofol, and the role of neuronal apoptosis and synaptic loss in propofol-induced long-term cognitive impairment needs to be elucidated. In this study, we investigated dynamic changes of neuronal apoptosis, neuronal density, synaptic density in hippocampal CA1 region and the prelimbic cortex (PrL), and long-term cognitive function after multiple or single exposure of propofol in neonatal rats. Results showed that single exposure of propofol only induced great neuronal apoptosis and deficit at postnatal day 9(P9); while multiple exposures of propofol could induce significant neuronal apoptosis, neuronal deficit and synaptic loss at P9, P14, P21, or P35 compared with intact, and spatial learning and memory impairment from P36 to P41. Results suggest that single exposure of propofol only induces transient neuronal apoptosis and deficit, while multiple exposures of propofol induce persistent neuronal apoptosis, neuronal deficit, synaptic loss, and long-term cognitive impairment. Furthermore, persistent neuronal deficit and disturbances in synapse formation but not transient neuronal apoptosis may contribute to long-term cognitive impairment.

  11. miR-455 inhibits neuronal cell death by targeting TRAF3 in cerebral ischemic stroke

    PubMed Central

    Yao, Shengtao; Tang, Bo; Li, Gang; Fan, Ruiming; Cao, Fang

    2016-01-01

    Ischemic stroke is one of the leading causes of brain disease, with high morbidity, disability, and mortality. MicroRNAs (miRNAs) have been identified as vital gene regulators in various types of human diseases. Accumulating evidence has suggested that aberrant expression of miRNAs play critical roles in the pathologies of ischemic stroke. Yet, the precise mechanism by which miRNAs control cerebral ischemic stroke remains unclear. In the present study, we explored whether miR-455 suppresses neuronal death by targeting TRAF3 in cerebral ischemic stroke. The expression levels of miR-455 and TRAF3 were detected by quantitative real-time polymerase chain reaction and Western blot. The role of miR-455 in cell death caused by oxygen–glucose deprivation (OGD) was assessed using Cell Counting Kit-8 (CCK-8) assay. The influence of miR-455 on infarct volume was evaluated in mouse brain after middle cerebral artery occlusion (MCAO). Bioinformatics softwares and luciferase analysis were used to find and confirm the targets of miR-455. The results showed that the expression levels of miR-455 significantly decreased in primary neuronal cells subjected to OGD and mouse brain subjected to MCAO. In addition, forced expression of miR-455 inhibited neuronal death and weakened ischemic brain infarction in focal ischemia-stroked mice. Furthermore, TRAF3 was proved to be a direct target of miR-455, and miR-455 could negatively suppress TRAF3 expression. Biological function analysis showed that TRAF3 silencing displayed the neuroprotective effect in ischemic stroke and could enhance miR-455-induced positive impact on ischemic injury both in vitro and in vivo. Taken together, miR-455 played a vital role in protecting neuronal cells from death by downregulating TRAF3 protein expression. These findings may represent a novel latent therapeutic target for cerebral ischemic stroke. PMID:27980410

  12. Specific Roles of Akt iso Forms in Apoptosis and Axon Growth Regulation in Neurons

    PubMed Central

    Diez, Hector; Garrido, Juan Jose; Wandosell, Francisco

    2012-01-01

    Akt is a member of the AGC kinase family and consists of three isoforms. As one of the major regulators of the class I PI3 kinase pathway, it has a key role in the control of cell metabolism, growth, and survival. Although it has been extensively studied in the nervous system, we have only a faint knowledge of the specific role of each isoform in differentiated neurons. Here, we have used both cortical and hippocampal neuronal cultures to analyse their function. We characterized the expression and function of Akt isoforms, and some of their substrates along different stages of neuronal development using a specific shRNA approach to elucidate the involvement of each isoform in neuron viability, axon development, and cell signalling. Our results suggest that three Akt isoforms show substantial compensation in many processes. However, the disruption of Akt2 and Akt3 significantly reduced neuron viability and axon length. These changes correlated with a tendency to increase in active caspase 3 and a decrease in the phosphorylation of some elements of the mTORC1 pathway. Indeed, the decrease of Akt2 and more evident the inhibition of Akt3 reduced the expression and phosphorylation of S6. All these data indicate that Akt2 and Akt3 specifically regulate some aspects of apoptosis and cell growth in cultured neurons and may contribute to the understanding of mechanisms of neuron death and pathologies that show deregulated growth. PMID:22509246

  13. Establishment of a Cell-Free System of Neuronal Apoptosis: Comparison of Premitochondrial, Mitochondrial, and Postmitochondrial Phases

    PubMed Central

    Ellerby, H. Michael; Martin, Seamus J.; Ellerby, Lisa M.; Naiem, Shahrouz S.; Rabizadeh, Shahrooz; Salvesen, Guy S.; Casiano, Carlos A.; Cashman, Neil R.; Green, Douglas R.; Bredesen, Dale E.

    1997-01-01

    Apoptosis is a fundamental process required for normal development of the nervous system and is triggered during neurodegenerative disease. To dissect the molecular events leading to neuronal cell death, we have developed a cell-free model of neuronal apoptosis. The model faithfully reproduces key elements of apoptosis, including chromatin condensation, DNA fragmentation, caspase activation/processing, and selective substrate cleavage. We report that cell-free apoptosis is activated in premitochondrial, mitochondrial, and postmitochondrial phases by tamoxifen, mastoparan, and cytochromec, respectively, allowing a functional ordering of these proapoptotic modulators. Furthermore, this is the first report of mitochondrial-mediated activation of cell-free apoptosis in a cell extract. Although Bcl-2 blocks activation at the premitochondrial and mitochondrial levels, it does not affect the postmitochondrial level. The cell-free system described here provides a valuable tool to elucidate the molecular events leading to neuronal cell death. PMID:9236228

  14. Apoptotic neuron-secreted HN12 inhibits cell apoptosis in Hirschsprung’s disease

    PubMed Central

    Du, Chunxia; Xie, Hua; Zang, Rujin; Shen, Ziyang; Li, Hongxing; Chen, Pingfa; Xu, Xiaoqun; Xia, Yankai; Tang, Weibing

    2016-01-01

    Perturbation in apoptosis can lead to Hirschsprung’s disease (HSCR), which is a genetic disorder of neural crest development. It is believed that long noncoding RNAs (lncRNAs) play a role in the progression of HSCR. This study shows that apoptotic neurons can suppress apoptosis of nonapoptotic cells by secreting exosomes that contain high levels of HN12 lncRNA. Elevated exogenous HN12 in nonapoptotic cells effectively inhibited cell apoptosis by maintaining the function of mitochondria, including the production of ATP and the release of cytochrome C. These results demonstrate that secreted lncRNAs may serve as signaling molecules mediating intercellular communication in HSCR. In addition, high HN12 levels in the circulation worked as a biomarker for predicting HSCR, providing a potential, novel, noninvasive diagnostic approach for early screening of HSCR. PMID:27853370

  15. Effect of baculovirus P35 protein on apoptosis in brain tissue of rats with acute cerebral infarction.

    PubMed

    Ji, J F; Ma, X H

    2015-08-10

    We explored the effect of baculovirus P35 protein on apoptosis in the brain tissue of rats with acute cerebral infarction (ACI). A rat model of middle cerebral artery infarction was created. The rats were randomly divided into sham, model, and treatment groups. Baculovirus P35 protein was injected into the intracranial arteries of the treatment group rats. The rats in the model group were given an equal volume of phosphate-buffered saline. The rats were sacrificed after 72 h and the brain tissue was separated. The levels of caspase-3, Bcl-2, and Bax mRNA, the brain cell apoptosis index, and the infarct size were determined. After 72 h, the levels of caspase-3 and Bax mRNA in the model and treatment groups were significantly greater than in the sham group, and the levels of Bcl-2 mRNA were significantly smaller (P < 0.05). The levels of caspase-3 and Bax mRNA were significantly lower in the treatment group than in the model group, and the level of Bcl-2 mRNA was significantly greater (P < 0.05). Compared with the sham group, the brain tissue apoptosis index and the cerebral infarction area increased significantly in the model and treatment groups (P < 0.05). The brain tissue apoptosis index and cerebral infarction area in the treatment group were significantly lower than in the model group (P < 0.05). Baculovirus P35 protein can effectively inhibit brain cell apoptosis in rats with ACI. It delayed apoptosis and necrosis in subjects with ACI tissue and had a protective effect on brain tissue.

  16. Neuronal and astrocytic interactions modulate brain endothelial properties during metabolic stresses of in vitro cerebral ischemia

    PubMed Central

    2014-01-01

    Neurovascular and gliovascular interactions significantly affect endothelial phenotype. Physiologically, brain endothelium attains several of its properties by its intimate association with neurons and astrocytes. However, during cerebrovascular pathologies such as cerebral ischemia, the uncoupling of neurovascular and gliovascular units can result in several phenotypical changes in brain endothelium. The role of neurovascular and gliovascular uncoupling in modulating brain endothelial properties during cerebral ischemia is not clear. Specifically, the roles of metabolic stresses involved in cerebral ischemia, including aglycemia, hypoxia and combined aglycemia and hypoxia (oxygen glucose deprivation and re-oxygenation, OGDR) in modulating neurovascular and gliovascular interactions are not known. The complex intimate interactions in neurovascular and gliovascular units are highly difficult to recapitulate in vitro. However, in the present study, we used a 3D co-culture model of brain endothelium with neurons and astrocytes in vitro reflecting an intimate neurovascular and gliovascular interactions in vivo. While the cellular signaling interactions in neurovascular and gliovascular units in vivo are much more complex than the 3D co-culture models in vitro, we were still able to observe several important phenotypical changes in brain endothelial properties by metabolically stressed neurons and astrocytes including changes in barrier, lymphocyte adhesive properties, endothelial cell adhesion molecule expression and in vitro angiogenic potential. PMID:24438487

  17. Association of Cell Adhesion Molecules Contactin-6 and Latrophilin-1 Regulates Neuronal Apoptosis

    PubMed Central

    Zuko, Amila; Oguro-Ando, Asami; Post, Harm; Taggenbrock, Renske L. R. E.; van Dijk, Roland E.; Altelaar, A. F. Maarten; Heck, Albert J. R.; Petrenko, Alexander G.; van der Zwaag, Bert; Shimoda, Yasushi; Pasterkamp, R. Jeroen; Burbach, J. Peter H.

    2016-01-01

    In view of important neurobiological functions of the cell adhesion molecule contactin-6 (Cntn6) that have emerged from studies on null-mutant mice and autism spectrum disorders patients, we set out to examine pathways underlying functions of Cntn6 using a proteomics approach. We identified the cell adhesion GPCR latrophilin-1 (Lphn1, a.k.a. CIRL1/CL, ADGRL1) as a binding partner for Cntn6 forming together a heteromeric cis-complex. Lphn1 expression in cultured neurons caused reduction in neurite outgrowth and increase in apoptosis, which was rescued by coexpression of Cntn6. In cultured neurons derived from Cntn6-/- mice, Lphn1 knockdown reduced apoptosis, suggesting that the observed apoptosis was Lphn1-dependent. In line with these data, the number of apoptotic cells was increased in the cortex of Cntn6-/- mice compared to wild-type littermate controls. These results show that Cntn6 can modulate the activity of Lphn1 by direct binding and suggests that Cntn6 may prevent apoptosis thereby impinging on neurodevelopment. PMID:28018171

  18. HIF-1 antagonizes p53-mediated apoptosis through a secreted neuronal tyrosinase.

    PubMed

    Sendoel, Ataman; Kohler, Ines; Fellmann, Christof; Lowe, Scott W; Hengartner, Michael O

    2010-06-03

    Hypoxia-inducible factor (HIF) is a transcription factor that regulates fundamental cellular processes in response to changes in oxygen concentration. HIFalpha protein levels are increased in most solid tumours and correlate with patient prognosis. The link between HIF and apoptosis, a major determinant of cancer progression and treatment outcome, is poorly understood. Here we show that Caenorhabditis elegans HIF-1 protects against DNA-damage-induced germ cell apoptosis by antagonizing the function of CEP-1, the homologue of the tumour suppressor p53. The antiapoptotic property of HIF-1 is mediated by means of transcriptional upregulation of the tyrosinase family member TYR-2 in the ASJ sensory neurons. TYR-2 is secreted by ASJ sensory neurons to antagonize CEP-1-dependent germline apoptosis. Knock down of the TYR-2 homologue TRP2 (also called DCT) in human melanoma cells similarly increases apoptosis, indicating an evolutionarily conserved function. Our findings identify a novel link between hypoxia and programmed cell death, and provide a paradigm for HIF-1 dictating apoptotic cell fate at a distance.

  19. HIF-1 antagonizes p53-mediated apoptosis through a secreted neuronal tyrosinase

    PubMed Central

    Sendoel, Ataman; Kohler, Ines; Fellmann, Christof; Lowe, Scott W.; Hengartner, Michael O.

    2012-01-01

    Hypoxia-inducible factor (HIF) is a transcription factor that regulates fundamental cellular processes in response to changes in oxygen concentration. HIFα protein levels are increased in most solid tumours and correlate with patient prognosis. The link between HIF and apoptosis, a major determinant of cancer progression and treatment outcome, is poorly understood. Here we show that Caenorhabditis elegans HIF-1 protects against DNA-damage-induced germ cell apoptosis by antagonizing the function of CEP-1, the homologue of the tumour suppressor p53. The antiapoptotic property of HIF-1 is mediated by means of transcriptional upregulation of the tyrosinase family member TYR-2 in the ASJ sensory neurons. TYR-2 is secreted by ASJ sensory neurons to antagonize CEP-1-dependent germline apoptosis. Knock down of the TYR-2 homologue TRP2 (also called DCT) in human melanoma cells similarly increases apoptosis, indicating an evolutionarily conserved function. Our findings identify a novel link between hypoxia and programmed cell death, and provide a paradigm for HIF-1 dictating apoptotic cell fate at a distance. PMID:20520707

  20. Electroacupuncture Treatment Alleviates Central Poststroke Pain by Inhibiting Brain Neuronal Apoptosis and Aberrant Astrocyte Activation

    PubMed Central

    Tian, Gui-Hua; Tao, Shan-Shan; Chen, Man-Tang; Li, Yu-Sang; Shang, Hong-Cai; Tang, Xiao-Yi; Chen, Jian-Xin

    2016-01-01

    Electroacupuncture (EA) is reported to effectively relieve the central poststroke pain (CPSP). However, the underlying mechanism remains unclear. The present study investigated the detailed mechanisms of action of EA treatment at different frequencies for CPSP. A CPSP model was established with a single collagenase injection to the left ventral posterolateral nucleus of the thalamus. The EA-treated groups then received EA treatment at frequency of 2, 2/15, or 15 Hz for 30 min daily for five days. The pain-related behavioral responses, neuronal apoptosis, glial activation, and the expression of pain signal transmission-related factors (β-catenin, COX-2, and NK-1R) were assessed using behavioral tests, Nissl staining, TUNEL staining, and immunohistochemical staining, respectively. The low-frequency EA treatment significantly (1) reduced brain tissue damage and hematoma sizes and (2) inhibited neuronal apoptosis, thereby exerting abirritative effects. Meanwhile, the high-frequency EA treatment induced a greater inhibition of the aberrant astrocyte activation, accompanied by the downregulation of the expressions of COX-2, β-catenin, and subsequently NK-1R, thereby alleviating inflammation and producing strong analgesic effects. Together, these findings suggest that CPSP is closely related to pathological changes of the neocortex and hippocampus. EA treatments at different frequencies may exert abirritative effects by inhibiting brain neuronal apoptosis and aberrant astrocyte activation in the brain. PMID:27774321

  1. Mitochondrial DNA Toxicity in Forebrain Neurons Causes Apoptosis, Neurodegeneration, and Impaired Behavior ▿

    PubMed Central

    Lauritzen, Knut H.; Moldestad, Olve; Eide, Lars; Carlsen, Harald; Nesse, Gaute; Storm, Johan F.; Mansuy, Isabelle M.; Bergersen, Linda H.; Klungland, Arne

    2010-01-01

    Mitochondrial dysfunction underlying changes in neurodegenerative diseases is often associated with apoptosis and a progressive loss of neurons, and damage to the mitochondrial genome is proposed to be involved in such pathologies. In the present study we designed a mouse model that allows us to specifically induce mitochondrial DNA toxicity in the forebrain neurons of adult mice. This is achieved by CaMKIIα-regulated inducible expression of a mutated version of the mitochondrial UNG DNA repair enzyme (mutUNG1). This enzyme is capable of removing thymine from the mitochondrial genome. We demonstrate that a continual generation of apyrimidinic sites causes apoptosis and neuronal death. These defects are associated with behavioral alterations characterized by increased locomotor activity, impaired cognitive abilities, and lack of anxietylike responses. In summary, whereas mitochondrial base substitution and deletions previously have been shown to correlate with premature and natural aging, respectively, we show that a high level of apyrimidinic sites lead to mitochondrial DNA cytotoxicity, which causes apoptosis, followed by neurodegeneration. PMID:20065039

  2. Mitochondrial DNA toxicity in forebrain neurons causes apoptosis, neurodegeneration, and impaired behavior.

    PubMed

    Lauritzen, Knut H; Moldestad, Olve; Eide, Lars; Carlsen, Harald; Nesse, Gaute; Storm, Johan F; Mansuy, Isabelle M; Bergersen, Linda H; Klungland, Arne

    2010-03-01

    Mitochondrial dysfunction underlying changes in neurodegenerative diseases is often associated with apoptosis and a progressive loss of neurons, and damage to the mitochondrial genome is proposed to be involved in such pathologies. In the present study we designed a mouse model that allows us to specifically induce mitochondrial DNA toxicity in the forebrain neurons of adult mice. This is achieved by CaMKIIalpha-regulated inducible expression of a mutated version of the mitochondrial UNG DNA repair enzyme (mutUNG1). This enzyme is capable of removing thymine from the mitochondrial genome. We demonstrate that a continual generation of apyrimidinic sites causes apoptosis and neuronal death. These defects are associated with behavioral alterations characterized by increased locomotor activity, impaired cognitive abilities, and lack of anxietylike responses. In summary, whereas mitochondrial base substitution and deletions previously have been shown to correlate with premature and natural aging, respectively, we show that a high level of apyrimidinic sites lead to mitochondrial DNA cytotoxicity, which causes apoptosis, followed by neurodegeneration.

  3. The hyperbaric oxygen preconditioning-induced brain protection is mediated by a reduction of early apoptosis after transient global cerebral ischemia.

    PubMed

    Ostrowski, Robert P; Graupner, Gerhart; Titova, Elena; Zhang, Jennifer; Chiu, Jeffrey; Dach, Neal; Corleone, Dalia; Tang, Jiping; Zhang, John H

    2008-01-01

    We hypothesized that the brain-protective effect of hyperbaric oxygen (HBO) preconditioning in a transient global cerebral ischemia rat model is mediated by the inhibition of early apoptosis. One hundred ten male Sprague-Dawley (SD) rats (300-350 g body weight) were allocated to the sham group and three other groups with 10 min of four-vessel occlusion, untreated or preconditioned with either 3 or 5 hyperbaric oxygenations. HBO preconditioning improved neurobehavioral scores and reduced mortality, decreased ischemic cell change, reduced the number of early apoptotic cells and hampered a conversion of early to late apoptotic alterations. HBO preconditioning reduced the immunoreactivity of phosphorylated p38 in vulnerable neurons and increased the expression of brain derived neurotrophic factor (BDNF) in early stage post-ischemia. However, preconditioning with 3 HBO treatments proved less beneficial than with 5 HBO treatments. We conclude that HBO preconditioning may be neuroprotective by reducing early apoptosis and inhibition of the conversion of early to late apoptosis, possibly through an increase in brain BDNF level and the suppression of p38 activation.

  4. Photobiomodulation partially rescues visual cortical neurons from cyanide-induced apoptosis.

    PubMed

    Liang, H L; Whelan, H T; Eells, J T; Meng, H; Buchmann, E; Lerch-Gaggl, A; Wong-Riley, M

    2006-05-12

    Near-infrared light via light-emitting diode treatment has documented therapeutic effects on neurons functionally inactivated by tetrodotoxin or methanol intoxication. Light-emitting diode pretreatment also reduced potassium cyanide-induced cell death, but the mode of death via the apoptotic or necrotic pathway was unclear. The current study tested our hypothesis that light-emitting diode rescues neurons from apoptotic cell death. Primary neuronal cultures from postnatal rat visual cortex were pretreated with light-emitting diode for 10 min at a total energy density of 30 J/cm2 before exposing to potassium cyanide for 28 h. With 100 or 300 microM potassium cyanide, neurons died mainly via the apoptotic pathway, as confirmed by electron microscopy, Hoechst 33258, single-stranded DNA, Bax, and active caspase-3. In the presence of caspase inhibitor I, the percentage of apoptotic cells in 300microM potassium cyanide was significantly decreased. Light-emitting diode pretreatment reduced apoptosis from 36% to 17.9% (100 microM potassium cyanide) and from 58.9% to 39.6% (300 microM potassium cyanide), representing a 50.3% and 32.8% reduction, respectively. Light-emitting diode pretreatment significantly decreased the expression of caspase-3 elicited by potassium cyanide. It also reversed the potassium cyanide-induced increased expression of Bax and decreased expression of Bcl-2 to control levels. Moreover, light-emitting diode decreased the intensity of 5-(and -6) chloromethy-2', 7-dichlorodihydrofluorescein diacetate acetyl ester, a marker of reactive oxygen species, in neurons exposed to 300 microM potassium cyanide. These results indicate that light-emitting diode pretreatment partially protects neurons against cyanide-induced caspase-mediated apoptosis, most likely by decreasing reactive oxygen species production, down-regulating pro-apoptotic proteins and activating anti-apoptotic proteins, as well as increasing energy metabolism in neurons as reported previously.

  5. Dentate granule neuron apoptosis and glia activation in murine hippocampus induced by trimethyltin exposure.

    PubMed

    Fiedorowicz, A; Figiel, I; Kamińska, B; Zaremba, M; Wilk, S; Oderfeld-Nowak, B

    2001-09-07

    We investigated the effect of trimethyltin (TMT), a well-known neurotoxicant, on murine hippocampal neurons and glial cells. Three days following intraperitoneal (i.p.) injection of TMT into 1-month-old Balb/c mice at a dose of 2.5 mg/kg body weight we detected damage of the dentate gyrus granular neurons. The dying cells displayed chromatin condensation and internucleosomal DNA fragmentation, which are the most characteristic features of apoptosis. To study, if prolyl oligopeptidase is engaged in neuronal apoptosis following TMT administration, we pretreated mice with the specific inhibitor--Fmoc-Pro-ProCN in doses of 5 and 10 mg/kg body weight (i.p. injection). Three days following injection we did not observe any attenuation of neurotoxic damage, regardless of inhibitor dose, indicating the lack of prolyl oligopeptidase contribution to neuronal injury caused by TMT. The neurodegeneration was associated with reactive astrogliosis in whole hippocampus, but particularly in injured dentate gyrus. The reactive astrocytes showed an increased nerve growth factor (NGF) expression in ventral as well as dorsal hippocampal parts. NGF immunoreactivity was also augmented in neurons of CA3/CA4 areas, which were almost totally spared after TMT intoxication. It suggested a role for this neurotrophin in protection of pyramidal cells from loss of connection between CA3/CA4 and dentate gyrus fields. The granule neurons' death was accompanied by increased histochemical staining with isolectin B4, a marker of microglia, in the region of neurodegeneration. The microglial cells displayed ramified and ameboid morphology, characteristic of their reactive forms. Activated microglia were the main source of interleukin 1beta (IL-1beta). It is possible that this cytokine may participate in neurodegeneration of granule cells. Alternatively, IL-1beta elaborated by microglia could play a role in increasing NGF expression, both in astroglia and in CA3/CA4 neurons.

  6. Laser speckle contrast reveals cerebral blood flow dynamics evoked by optogenetically controlled neuronal activity

    NASA Astrophysics Data System (ADS)

    Li, Nan; Thakor, Nitish V.; Pelled, Galit

    2013-03-01

    As a critical basis of functional brain imaging, neurovascular coupling describes the link between neuronal and hemodynamic changes. The majority of in vivo neurovascular coupling studies was performed by inducing sensory stimulation via afferent inputs. Unfortunately such an approach results in recruiting of multiple types of cells, which confounds the explanation of neuronal roles in stimulus evoked hemodynamic changes. Recently optogenetics has emerged to provide immediate control of neurons by exciting or inhibiting genetically engineered neurons expressing light sensitive proteins. However, there is a need for optical methods capable of imaging the concurrent hemodynamic changes. We utilize laser speckle contrast imaging (LSCI) to obtain high resolution display of cerebral blood flow (CBF) in the vicinity of the targeted neural population. LSCI is a minimally invasive method for imaging CBF in microvessels through thinned skull, and produces images with high spatiotemporal resolution, wide field of view. In the integrated system light sources with different wavelengths and band-passing/blocking filters were used to allow simultaneous optical manipulation of neuronal activities and optical imaging of corresponding CBF. Experimental studies were carried out in a rodent model expressing channalrhodopsin (ChR2) in excitatory neurons in the somatosensory cortex (S1). The results demonstrated significant increases of CBF in response to ChR2 stimulation (exciting neuronal firing) comparable to the CBF response to contralateral forepaw stimulation. The approach promises to be an exciting minimally invasive method to study neurovascular coupling. The complete system provides a novel approach for broad neuroscience applications.

  7. Accelerated infarct development, cytogenesis and apoptosis following transient cerebral ischemia in aged rats.

    PubMed

    Popa-Wagner, Aurel; Badan, Irina; Walker, Lary; Groppa, Sergiu; Patrana, Nicoleta; Kessler, Christof

    2007-03-01

    Old age is associated with a deficient recovery from stroke, but the cellular mechanisms underlying such phenomena are poorly understood. To address this issue, focal cerebral ischemia was produced by reversible occlusion of the right middle cerebral artery in 3- and 20-month-old male Sprague-Dawley rats. Aged rats showed a delayed and suboptimal functional recovery in the post-stroke period. Using BrdU-labeling, quantitative immunohistochemistry and 3-D reconstruction of confocal images, we found that aged rats are predisposed to rapidly develop an infarct within the first few days after ischemia. The emergence of the necrotic zone is associated with a high rate of cellular degeneration, premature accumulation of proliferating BrdU-positive cells that appear to emanate from capillaries in the infarcted area, and a large number of apoptotic cells. With double labeling techniques, we were able to identify, for the first time, over 60% of BrdU-positive cells either as reactive microglia (45%), oligodendrocyte progenitors (17%), astrocytes (23%), CD8+ lymphocytes (4%), or apoptotic cells (<1%). Paradoxically, despite a robust reactive phenotype of microglia and astrocytes in aged rats, at 1-week post-stroke, the number of proliferating microglia and astrocytes was lower in aged rats than in young rats. Our data indicate that aging is associated with rapid infarct development and a poor prognosis for full recovery from stroke that is correlated with premature cellular proliferation and increased cellular degeneration and apoptosis in the infarcted area.

  8. Serum UCH-L1 as a Novel Biomarker to Predict Neuronal Apoptosis Following Deep Hypothermic Circulatory Arrest

    PubMed Central

    Zhang, Ya-Ping; Zhu, Yao-Bin; Duan, Dayue Darrel; Fan, Xiang-Ming; He, Yan; Su, Jun-Wu; Liu, Ying-Long

    2015-01-01

    Background: Deep hypothermic circulatory arrest (DHCA) has been used in cardiac surgery involving infant complex congenital heart disease and aortic dissection. DHCA carries a risk of neuronal apoptotic death in brain. Serum ubiquitin C-terminal hydrolase L1 (UCH-L1) level is elevated in a number of neurological diseases involving neuron injury and death. We studied the hypothesis that UCH-L1 may be a potential biomarker for DHCA-induced ischemic neuronal apoptosis. Methods: Anesthetized piglets were used to perform cardiopulmonary bypass (CPB). DHCA was induced for 1 hour followed by CPB rewarming. Blood samples were collected and serum UCH-L1 levels were measured. Neuron apoptosis and Bax and Bcl-2 proteins in hippocampus were examined. The relationship between neuron apoptosis and UCH-L1 level was determined by receiver operating characteristics (ROC) curves and correlation analysis. Results: DHCA resulted in marked neuronal apoptosis, significant increase in Bax:Bcl-2 ratio in hippocampus and UCH-L1 level elevations in serum (all P<0.05). Positive correlation was obtained between serum UCH-L1 level and the severity of neuron apoptosis (r= 0.78, P<0.01). By ROC, the area under the curve were 0.88 (95% CI: 0.74-0.99; P<0.01), 0.81 (95% CI: 0.81-0.96; P<0.05), 0.71 (95% CI: 0.47-0.92; P=0.11) for UCH-L1, Bax/Bcl-2 ratio and Bax, respectively. Using a cut-off point of 0.25, the UCH-L1 predicted neuronal apoptosis with a sensitivity of 85% and specificity of 57%. Conclusion: Serum UCH-L1, as an easy and quick measurable biomarker, can predict neural apoptosis induced by DHCA. The elevation in UCH-L1 concentration is consistent with the severity of neural apoptosis following DHCA. PMID:26180514

  9. Interacting partners of macrophage-secreted cathepsin B contribute to HIV-induced neuronal apoptosis

    PubMed Central

    CANTRES-ROSARIO, Yisel M.; HERNANDEZ, Natalia; NEGRON, Karla; PEREZ-LASPIUR, Juliana; LESZYK, John; SHAFFER, Scott A.; MELENDEZ, Loyda M.

    2015-01-01

    Objective HIV-1 infection of macrophages increases cathepsin B secretion and induces neuronal apoptosis, but the molecular mechanism remains unclear. Design We identified macrophage secreted cathepsin B protein interactions extracellularly and their contribution to neuronal death in vitro. Methods Cathepsin B was immunoprecipitated from monocyte-derived macrophage supernatants after 12 days post-infection. The cathepsin B interactome was quantified by label-free tandem mass spectrometry and compared to uninfected supernatants. Proteins identified were validated by western blot. Neurons were exposed to macrophage-conditioned media in presence or absence of antibodies against cathepsin B and interacting proteins. Apoptosis was measured using TUNEL labeling. Immunohistochemistry of post-mortem brain tissue samples from healthy, HIV-infected, and Alzheimer’s disease patients was performed to observe the ex vivo expression of the proteins identified. Results Nine proteins co-immunoprecipitated differentially with cathepsin B between uninfected and HIV-infected macrophages. Serum amyloid p component (SAPC) -cathepsin B interaction increased in HIV-infected macrophage supernatants, while matrix metalloprotease 9 (MMP-9) -cathepsin B interaction decreased. Pre-treatment of HIV-infected macrophage-conditioned media with antibodies against cathepsin B and SAPC decreased neuronal apoptosis. The addition of MMP-9 antibodies was not protective. SAPC was over-expressed in post-mortem brain tissue from HIV-positive neurocognitive impaired patients compared to HIV positive with normal cognition and healthy controls, while MMP-9 expression was similar in all tissues. Conclusions Inhibiting SAPC-cathepsin B interaction protects against HIV–induced neuronal death and may help to find alternative treatments for HIV-associated neurocognitive disorders. PMID:26208400

  10. Widespread heterogeneous neuronal loss across the cerebral cortex in Huntington's disease.

    PubMed

    Nana, Alissa L; Kim, Eric H; Thu, Doris C V; Oorschot, Dorothy E; Tippett, Lynette J; Hogg, Virginia M; Synek, Beth J; Roxburgh, Richard; Waldvogel, Henry J; Faull, Richard L M

    2014-01-01

    Huntington's disease is an autosomal dominant neurodegenerative disease characterized by neuronal degeneration in the basal ganglia and cerebral cortex, and a variable symptom profile. Although progressive striatal degeneration is known to occur and is related to symptom profile, little is known about the cellular basis of symptom heterogeneity across the entire cerebral cortex. To investigate this, we have undertaken a double blind study using unbiased stereological cell counting techniques to determine the pattern of cell loss in six representative cortical regions from the frontal, parietal, temporal, and occipital lobes in the brains of 14 Huntington's disease cases and 15 controls. The results clearly demonstrate a widespread loss of total neurons and pyramidal cells across all cortical regions studied, except for the primary visual cortex. Importantly, the results show that cell loss is remarkably variable both within and between Huntington's disease cases. The results also show that neuronal loss in the primary sensory and secondary visual cortices relate to Huntington's disease motor symptom profiles, and neuronal loss across the associational cortices in the frontal, parietal and temporal lobes is related to both Huntington's disease motor and to mood symptom profiles. This finding considerably extends a previous study (Thu et al., Brain, 2010; 133:1094-1110) which showed that neuronal loss in the primary motor cortex was related specifically to the motor symptom profiles while neuronal loss in the anterior cingulate cortex was related specifically to mood symptom profiles. The extent of cortical cell loss in the current study was generally related to the striatal neuropathological grade, but not to CAG repeat length on the HTT gene. Overall our findings show that Huntington's disease is characterized by a heterogeneous pattern of neuronal cell loss across the entire cerebrum which varies with symptom profile.

  11. Mesenchymal stem cells protect neurons against hypoxic-ischemic injury via inhibiting parthanatos, necroptosis, and apoptosis, but not autophagy.

    PubMed

    Kong, Deyan; Zhu, Juehua; Liu, Qian; Jiang, Yongjun; Xu, Lily; Luo, Ning; Zhao, Zhenqiang; Zhai, Qijin; Zhang, Hao; Zhu, Mingyue; Liu, Xinfeng

    2017-03-01

    Cellular therapy with mesenchymal stem cells (MSCs) protects cortical neurons against hypoxic-ischemic injury of stroke. Although sorts of efforts have been made to confirm the neuroprotective effect of MSCs on neurons against hypoxic-ischemic injury, the mechanism is until now far away from clear. Here in this study, oxygen-glucose deprivation (OGD)-injured neuron model was applied to mimic the neuronal hypoxic-ischemic injury in vitro. Co-culturing with MSCs in a transwell co-culture system, the OGD injured neurons were rescued by 75.0 %. Further data demonstrated that co-culturing with MSCs protected the cortical neurons from the OGD-induced parthanatos by alleviating apoptosis-inducing factor (AIF) nuclear translocation; attenuated the neuronal necroptosis by down-regulating the expression of the two essential kinases in necroptosis, receptor interacting protein kinase1 (RIP1) and 3 (RIP3); rescued the neurons from apoptosis by deactivating caspase-3; whilst performed no significant influence on OGD-induced neuronal autophagy, according to its failed regulation on Beclin1. In conclusion, MSCs potentially protect the cortical neurons from OGD-injury in vitro, through rescuing neurons from the cell death of parthanatos, necroptosis, and apoptosis, but not autophagy, which could provide some evidence to the mechanism explanation on stem cell treatment for ischemic stroke.

  12. Ceramides in Alzheimer's Disease: Key Mediators of Neuronal Apoptosis Induced by Oxidative Stress and Aβ Accumulation

    PubMed Central

    Jazvinšćak Jembrek, Maja; Hof, Patrick R.; Šimić, Goran

    2015-01-01

    Alzheimer's disease (AD), the most common chronic and progressive neurodegenerative disorder, is characterized by extracellular deposits of amyloid β-peptides (Aβ) and intracellular deposits of hyperphosphorylated tau (phospho-tau) protein. Ceramides, the major molecules of sphingolipid metabolism and lipid second messengers, have been associated with AD progression and pathology via Aβ generation. Enhanced levels of ceramides directly increase Aβ through stabilization of β-secretase, the key enzyme in the amyloidogenic processing of Aβ precursor protein (APP). As a positive feedback loop, the generated oligomeric and fibrillar Aβ induces a further increase in ceramide levels by activating sphingomyelinases that catalyze the catabolic breakdown of sphingomyelin to ceramide. Evidence also supports important role of ceramides in neuronal apoptosis. Ceramides may initiate a cascade of biochemical alterations, which ultimately leads to neuronal death by diverse mechanisms, including depolarization and permeabilization of mitochondria, increased production of reactive oxygen species (ROS), cytochrome c release, Bcl-2 depletion, and caspase-3 activation, mainly by modulating intracellular signalling, particularly along the pathways related to Akt/PKB kinase and mitogen-activated protein kinases (MAPKs). This review summarizes recent findings related to the role of ceramides in oxidative stress-driven neuronal apoptosis and interplay with Aβ in the cascade of events ending in neuronal degeneration. PMID:26090071

  13. Ceramides in Alzheimer's Disease: Key Mediators of Neuronal Apoptosis Induced by Oxidative Stress and Aβ Accumulation.

    PubMed

    Jazvinšćak Jembrek, Maja; Hof, Patrick R; Šimić, Goran

    2015-01-01

    Alzheimer's disease (AD), the most common chronic and progressive neurodegenerative disorder, is characterized by extracellular deposits of amyloid β-peptides (Aβ) and intracellular deposits of hyperphosphorylated tau (phospho-tau) protein. Ceramides, the major molecules of sphingolipid metabolism and lipid second messengers, have been associated with AD progression and pathology via Aβ generation. Enhanced levels of ceramides directly increase Aβ through stabilization of β-secretase, the key enzyme in the amyloidogenic processing of Aβ precursor protein (APP). As a positive feedback loop, the generated oligomeric and fibrillar Aβ induces a further increase in ceramide levels by activating sphingomyelinases that catalyze the catabolic breakdown of sphingomyelin to ceramide. Evidence also supports important role of ceramides in neuronal apoptosis. Ceramides may initiate a cascade of biochemical alterations, which ultimately leads to neuronal death by diverse mechanisms, including depolarization and permeabilization of mitochondria, increased production of reactive oxygen species (ROS), cytochrome c release, Bcl-2 depletion, and caspase-3 activation, mainly by modulating intracellular signalling, particularly along the pathways related to Akt/PKB kinase and mitogen-activated protein kinases (MAPKs). This review summarizes recent findings related to the role of ceramides in oxidative stress-driven neuronal apoptosis and interplay with Aβ in the cascade of events ending in neuronal degeneration.

  14. Astrocyte hepcidin is a key factor in LPS-induced neuronal apoptosis.

    PubMed

    You, Lin-Hao; Yan, Cai-Zhen; Zheng, Bing-Jie; Ci, Yun-Zhe; Chang, Shi-Yang; Yu, Peng; Gao, Guo-Fen; Li, Hai-Yan; Dong, Tian-Yu; Chang, Yan-Zhong

    2017-03-16

    Inflammatory responses involving microglia and astrocytes contribute to the pathogenesis of neurodegenerative diseases (NDs). In addition, inflammation is tightly linked to iron metabolism dysregulation. However, it is not clear whether the brain inflammation-induced iron metabolism dysregulation contributes to the NDs pathogenesis. Herein, we demonstrate that the expression of the systemic iron regulatory hormone, hepcidin, is induced by lipopolysaccharide (LPS) through the IL-6/STAT3 pathway in the cortex and hippocampus. In this paradigm, activated glial cells are the source of IL-6, which was essential in the iron overload-activated apoptosis of neurons. Disrupting astrocyte hepcidin expression prevented the apoptosis of neurons, which were able to maintain levels of FPN1 adequate to avoid iron accumulation. Together, our data are consistent with a model whereby inflammation initiates an intercellular signaling cascade in which activated microglia, through IL-6 signaling, stimulate astrocytes to release hepcidin which, in turn, signals to neurons, via hepcidin, to prevent their iron release. Such a pathway is relevant to NDs in that it links inflammation, microglia and astrocytes to neuronal damage.

  15. Sugammadex, a neuromuscular blockade reversal agent, causes neuronal apoptosis in primary cultures.

    PubMed

    Palanca, José M; Aguirre-Rueda, Diana; Granell, Manuel V; Aldasoro, Martin; Garcia, Alma; Iradi, Antonio; Obrador, Elena; Mauricio, Maria Dolores; Vila, Jose; Gil-Bisquert, Anna; Valles, Soraya L

    2013-01-01

    Sugammadex, a γ-cyclodextrin that encapsulates selectively steroidal neuromuscular blocking agents, such as rocuronium or vecuronium, has changed the face of clinical neuromuscular pharmacology. Sugammadex allows a rapid reversal of muscle paralysis. Sugammadex appears to be safe and well tolerated. Its blood-brain barrier penetration is poor (< 3% in rats), and thus no relevant central nervous toxicity is expected. However the blood brain barrier permeability can be altered under different conditions (i.e. neurodegenerative diseases, trauma, ischemia, infections, or immature nervous system). Using MTT, confocal microscopy, caspase-3 activity, cholesterol quantification and Western-blot we determine toxicity of Sugammadex in neurons in primary culture. Here we show that clinically relevant sugammadex concentrations cause apoptotic/necrosis neuron death in primary cultures. Studies on the underlying mechanism revealed that sugammadex-induced activation of mitochondria-dependent apoptosis associates with depletion of neuronal cholesterol levels. Furthermore SUG increase CytC, AIF, Smac/Diablo and CASP-3 protein expression in cells in culture. Potential association of SUG-induced alteration in cholesterol homeostasis with oxidative stress and apoptosis activation occurs. Furthermore, resistance/sensitivity to oxidative stress differs between neuronal cell types.

  16. Sugammadex, a Neuromuscular Blockade Reversal Agent, Causes Neuronal Apoptosis in Primary Cultures

    PubMed Central

    Palanca, José M.; Aguirre-Rueda, Diana; Granell, Manuel V.; Aldasoro, Martin; Garcia, Alma; Iradi, Antonio; Obrador, Elena; Mauricio, Maria Dolores; Vila, Jose; Gil-Bisquert, Anna; Valles, Soraya L.

    2013-01-01

    Sugammadex, a γ-cyclodextrin that encapsulates selectively steroidal neuromuscular blocking agents, such as rocuronium or vecuronium, has changed the face of clinical neuromuscular pharmacology. Sugammadex allows a rapid reversal of muscle paralysis. Sugammadex appears to be safe and well tolerated. Its blood-brain barrier penetration is poor (< 3% in rats), and thus no relevant central nervous toxicity is expected. However the blood brain barrier permeability can be altered under different conditions (i.e. neurodegenerative diseases, trauma, ischemia, infections, or immature nervous system). Using MTT, confocal microscopy, caspase-3 activity, cholesterol quantification and Western-blot we determine toxicity of Sugammadex in neurons in primary culture. Here we show that clinically relevant sugammadex concentrations cause apoptotic/necrosis neuron death in primary cultures. Studies on the underlying mechanism revealed that sugammadex-induced activation of mitochondria-dependent apoptosis associates with depletion of neuronal cholesterol levels. Furthermore SUG increase CytC, AIF, Smac/Diablo and CASP-3 protein expression in cells in culture. Potential association of SUG-induced alteration in cholesterol homeostasis with oxidative stress and apoptosis activation occurs. Furthermore, resistance/sensitivity to oxidative stress differs between neuronal cell types. PMID:23983586

  17. Methazolamide improves neurological behavior by inhibition of neuron apoptosis in subarachnoid hemorrhage mice

    PubMed Central

    Li, Mingchang; Wang, Wei; Mai, Haojian; Zhang, Xinmu; Wang, Jian; Gao, Yufeng; Wang, Yuefei; Deng, Gang; Gao, Ling; Zhou, Shuanhu; Chen, Qianxue; Wang, Xin

    2016-01-01

    Subarachnoid hemorrhage (SAH) results in significant nerve dysfunction, such as hemiplegia, mood disorders, cognitive and memory impairment. Currently, no clear measures can reduce brain nerve damage. The study of brain nerve protection after SAH is of great significance. We aim to evaluate the protective effects and the possible mechanism of methazolamide in C57BL/6J SAH animal model in vivo and in blood-induced primary cortical neuron (PCNs) cellular model of SAH in vitro. We demonstrate that methazolamide accelerates the recovery of neurological damage, effectively relieves cerebral edema, and improves cognitive function in SAH mice as well as offers neuroprotection in blood- or hemoglobin-treated PCNs and partially restores normal neuronal morphology. In addition, western blot analyses show obviously decreased expression of active caspase-3 in methazolamide-treated SAH mice comparing with vehicle-treated SAH animals. Furthermore, methazolamide effectively inhibits ROS production in PCNs induced by blood exposure or hemoglobin insult. However, methazolamide has no protective effects in morality, fluctuation of cerebral blood flow, SAH grade, and cerebral vasospasm of SAH mice. Given methazolamide, a potent carbonic anhydrase inhibitor, can penetrate the blood–brain barrier and has been used in clinic in the treatment of ocular conditions, it provides potential as a novel therapy for SAH. PMID:27731352

  18. GVS-111 prevents oxidative damage and apoptosis in normal and Down's syndrome human cortical neurons.

    PubMed

    Pelsman, Alejandra; Hoyo-Vadillo, Carlos; Gudasheva, Tatiana A; Seredenin, Sergei B; Ostrovskaya, Rita U; Busciglio, Jorge

    2003-05-01

    The neuroprotective activity of a novel N-acylprolyl-containing dipeptide analog of the nootropic 2-oxo-1-pyrrolidine acetamide (Piracetam) designated as GVS-111 (DVD-111/Noopept) was tested in two in vitro models of neuronal degeneration mediated by oxidative stress: normal human cortical neurons treated with H(2)O(2), and Down's syndrome (DS) cortical neurons. Incubation of normal cortical neurons with 50 microM H(2)O(2) for 1h resulted in morphological and structural changes consistent with neuronal apoptosis and in the degeneration of more than 60% of the neurons present in the culture. GVS-111 significantly increased neuronal survival after H(2)O(2)-treatment displaying a dose-dependent neuroprotective activity from 10nM to 100 microM, and an IC(50) value of 1.21+/-0.07 microM. GVS-111 inhibited the accumulation of intracellular free radicals and lipid peroxidation damage in neurons treated with H(2)O(2) or FeSO(4), suggesting an antioxidant mechanism of action. GVS-111 exhibited significantly higher neuroprotection compared to the standard cognition enhancer Piracetam, or to the antioxidants Vitamin E, propyl gallate and N-tert-butyl-2-sulpho-phenylnitrone (s-PBN). In DS cortical cultures, chronic treatment with GVS-111 significantly reduced the appearance of degenerative changes and enhanced neuronal survival. The results suggest that the neuroprotective effect of GVS-111 against oxidative damage and its potential nootropic activity may present a valuable therapeutic combination for the treatment of mental retardation and chronic neurodegenerative disorders.

  19. Phenylethanoid glycosides from Cistanches salsa inhibit apoptosis induced by 1-methyl-4-phenylpyridinium ion in neurons.

    PubMed

    Tian, Xue-Fei; Pu, Xiao-Ping

    2005-02-10

    In our study we investigated the neuroprotective effects of phenylethanoid glycosides (PhGs) from Cistanches salsa on 1-methyl-4-phenylpyridinium ion (MPP(+))-induced apoptosis in cerebellar granule neurons (CGNs). CGNs were treated with 100 microM MPP(+) for 24h to induce apoptosis, simultaneously CGNs were incubated with PhGs at 10, 20 and 40 microg/ml, respectively. In addition CGNs were pretreated with PhGs at 20 microg/ml for 6, 12, 24 h, respectively, and then treated with 100 microM MPP(+) for 24 h. 3-(4,5-Dimethylthiazol-2-ylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed that the treatment of CGNs with PhGs inhibited the decrease of cell viability induced by MPP(+). The activation of caspase-3 and caspase-8 was induced by MPP(+) in apoptosis. The caspase-3 and caspase-8 fluorogenic assays showed that the treatments of CGNs with PhGs efficiently suppressed the activation of caspase-3 and caspase-8 induced by MPP(+). It is concluded that PhGs can prevent the MPP(+)-induced apoptosis in CGNs and exert its anti-apoptosis effect by inhibiting caspase-3 and caspase-8 activities.

  20. Sphk1 mediates neuroinflammation and neuronal injury via TRAF2/NF-κB pathways in activated microglia in cerebral ischemia reperfusion.

    PubMed

    Su, Danying; Cheng, Yuefeng; Li, Shi; Dai, Dawei; Zhang, Wei; Lv, Manhua

    2017-04-15

    Sphingosine kinase 1 (Sphk1), a key enzyme responsible for phosphorylating sphingosine into sphingosine1-phosphate (S1P), plays an important role in mediating post-stroke neuroinflammation. However, the pathway and mechanism of the Sphk1-mediated inflammatory response remains unknown. In this study, we found that suppression of Sphk1 decreased IL17 production and relieved neuronal damage induced by microglia in cerebral ischemia reperfusion (IR) or in an in vitro oxygen-glucose deprivation reperfusion (OGDR) system. Inhibition of Sphk1 with an inhibitor or siRNA decreased tumor necrosis factor receptor-associated factor 2 (TRAF2) and nuclear factor-kappa B (NF-κB) sequentially in microglia in response to IR or OGDR. Moreover, we also found that after suppression of TRAF2 or NF-κB by siRNA in microglia, reductions in the downstream molecules NF-κB and IL-17 and in neuronal apoptosis were observed in response to OGDR. Taken together, we hypothesize that Sphk1, TRAF2 and NF-κB form an axis that leads to increased IL-17 and neuronal apoptosis. This axis may be a potential therapeutic target to control neuroinflammation in brain IR.

  1. Thiamine deficiency caused by thiamine antagonists triggers upregulation of apoptosis inducing factor gene expression and leads to caspase 3-mediated apoptosis in neuronally differentiated rat PC-12 cells.

    PubMed

    Chornyy, Sergiy; Parkhomenko, Julia; Chorna, Nataliya

    2007-01-01

    Recent evidence suggests that alterations in oxidative metabolism induced by thiamine deficiency lead to neuronal cell death. However, the molecular mechanisms underlying this process are still under extensive investigation. Here, we report that rat pheochromocytoma PC-12 cells differentiated in the presence of NGF into neurons undergo apoptosis due to thiamine deficiency caused by antagonists of thiamine - amprolium, pyrithiamine and oxythiamine. Confocal laser scanning fluorescence microscopy revealed that annexin V binds to PC-12 cells in presence of thiamine antagonists after 72 h incubation. Results also show that thiamine antagonists trigger upregulation of gene expression of mitochondrial-derived apoptosis inducing factor, DNA fragmentation, cleavage of caspase 3 and translocation of active product to the nucleus. We therefore propose that apoptosis induced by amprolium, pyrithiamine or oxythiamine occurs via the mitochondria-dependent caspase 3-mediated signaling pathway. In addition, our data indicate that pyrithiamine and oxythiamine are more potent inducers of apoptosis than amprolium.

  2. Association of Cerebral Amyloidosis, Blood Pressure, and Neuronal Injury with Late-Life Onset Depression

    PubMed Central

    Byun, Min Soo; Choe, Young Min; Sohn, Bo Kyung; Yi, Dahyun; Han, Ji Young; Park, Jinsick; Choi, Hyo Jung; Baek, Hyewon; Lee, Jun Ho; Kim, Hyun Jung; Kim, Yu Kyeong; Yoon, Eun Jin; Sohn, Chul-Ho; Woo, Jong Inn; Lee, Dong Young

    2016-01-01

    Previous literature suggests that Alzheimer's disease (AD) process may contribute to late-life onset depression (LLOD). Therefore, we investigated the association of LLOD with cerebral amyloidosis and neuronal injury, the two key brain changes in AD, along with vascular risks. Twenty nine non-demented individuals who first experienced major depressive disorder (MDD) after age of 60 years were included as LLOD subjects, and 27 non-demented elderly individuals without lifetime experience of MDD were included as normal controls (NC). Comorbid mild cognitive impairment (MCI) was diagnosed in 48% of LLOD subjects and in 0% of NC. LLOD, irrespective of comorbid MCI diagnosis, was associated with prominent prefrontal cortical atrophy. Compared to NC, LLOD subjects with comorbid MCI (LLODMCI) showed increased cerebral 11C-Pittsburg compound B (PiB) retention and plasma beta-amyloid 1–40 and 1–42 peptides, as measures of cerebral amyloidosis; and, such relationship was not observed in overall LLOD or LLOD without MCI (LLODwoMCI). LLOD subjects, particularly the LLODwoMCI, had higher systolic blood pressure (SBP) than NC. When analyzed in the same multiple logistic regression model that included prefrontal gray matter (GM) density, cerebral amyloidosis, and SBP as independent variables, only prefrontal GM density showed a significant independent association with LLOD regardless of MCI comorbidity status. Our findings suggest AD process might be related to LLOD via prefrontal neuronal injury in the MCI stage, whereas vascular processes—SBP elevation, in particular—are associated with LLOD via prefrontal neuronal injury even in cognitively intact or less impaired individuals. PMID:27790137

  3. Luoyutong Treatment Promotes Functional Recovery and Neuronal Plasticity after Cerebral Ischemia-Reperfusion Injury in Rats.

    PubMed

    Wang, Ning-Qun; Wang, Li-Ye; Zhao, Hai-Ping; Liu, Ping; Wang, Rong-Liang; Song, Jue-Xian; Gao, Li; Ji, Xun-Ming; Luo, Yu-Min

    2015-01-01

    Luoyutong (LYT) capsule has been used to treat cerebrovascular diseases clinically in China and is now patented and approved by the State Food and Drug Administration. In this retrospective validation study we investigated the ability of LYT to protect against cerebral ischemia-reperfusion injury in rats. Cerebral ischemia-reperfusion injury was induced by middle cerebral artery occlusion followed by reperfusion. Capsule containing LYT (high dose and medium dose) as treatment group and Citicoline Sodium as positive control treatment group were administered daily to rats 30 min after reperfusion. Treatment was continued for either 3 days or 14 days. A saline solution was administered to control animals. Behavior tests were performed after 3 and 14 days of treatment. Our findings revealed that LYT treatment improved the neurological outcome, decreased cerebral infarction volume, and reduced apoptosis. Additionally, LYT improved neural plasticity, as the expression of synaptophysin, microtubule associated protein, and myelin basic protein was upregulated by LYT treatment, while neurofilament 200 expression was reduced. Moreover, levels of brain derived neurotrophic factor and basic fibroblast growth factor were increased. Our results suggest that LYT treatment may protect against ischemic injury and improve neural plasticity.

  4. Luoyutong Treatment Promotes Functional Recovery and Neuronal Plasticity after Cerebral Ischemia-Reperfusion Injury in Rats

    PubMed Central

    Wang, Ning-qun; Wang, Li-ye; Zhao, Hai-ping; Liu, Ping; Wang, Rong-liang; Song, Jue-xian; Gao, Li; Ji, Xun-ming; Luo, Yu-min

    2015-01-01

    Luoyutong (LYT) capsule has been used to treat cerebrovascular diseases clinically in China and is now patented and approved by the State Food and Drug Administration. In this retrospective validation study we investigated the ability of LYT to protect against cerebral ischemia-reperfusion injury in rats. Cerebral ischemia-reperfusion injury was induced by middle cerebral artery occlusion followed by reperfusion. Capsule containing LYT (high dose and medium dose) as treatment group and Citicoline Sodium as positive control treatment group were administered daily to rats 30 min after reperfusion. Treatment was continued for either 3 days or 14 days. A saline solution was administered to control animals. Behavior tests were performed after 3 and 14 days of treatment. Our findings revealed that LYT treatment improved the neurological outcome, decreased cerebral infarction volume, and reduced apoptosis. Additionally, LYT improved neural plasticity, as the expression of synaptophysin, microtubule associated protein, and myelin basic protein was upregulated by LYT treatment, while neurofilament 200 expression was reduced. Moreover, levels of brain derived neurotrophic factor and basic fibroblast growth factor were increased. Our results suggest that LYT treatment may protect against ischemic injury and improve neural plasticity. PMID:26697095

  5. Lyophilized Powder of Catalpol and Puerarin Protected Cerebral Vessels from Ischemia by Its Anti-apoptosis on Endothelial Cells

    PubMed Central

    Liu, Yang; Tang, Qing; Shao, Siying; Chen, Yi; Chen, Weihai; Xu, Xiaoyu

    2017-01-01

    Catalpol and puerarin are two monomers of Rehmannia glutinosa and Lobed Kudzuvine Root, which are two herbs commonly used together in ancient prescriptions of traditional Chinese medicine for cerebral ischemia. Our previous study shows that the lyophilized powder of the two monomers improved the outcome of cerebral ischemia excellently in rodents. However, if it protects vessels from ischemia is unknown. The present research studied the protection of lyophilized powder of catalpol and puerarin (CP) on endothelial cells and the relative mechanism in vivo and in vitro. Middle cerebral artery occlusion (MCAO) rats were used to study the improvement of CP on neurological deficiency, regional cerebral blood flow (rCBF), and infarct volume. The morphology of vessels and the apoptosis of brain vascular endothelial cells (BVECs) were observed and detected by immunohistochemistry approaches. To study how CP protected primary BVECs (pBVECs) from ischemic penumbra, oxygen glucose deprivation (OGD)-damaged pBVECs were cultured in the condition of insufficient nutrition and low oxygen which recapitulate the low perfusion of ischemic penumbra. Using the cell model, the mechanism by which CP protected pBVECs was studied by shRNA and pathway inhibitors. CP at the dose of 65.4 mg/kg increased regional cerebral blood flow (rCBF), reduced infarct volume, protected vessel integrity and inhibited endothelial cell apoptosis in vivo. But it only improved rCBF, vessel integrity and BVECs apoptosis at the dose of 32.7 mg/kg. In vitro, the protection of CP on pBVECs was proved to be ERK/HIF-1a- and PI3K/AKT/mTOR/HIF-1a-dependent. This study indicates a possibility of CP being a new drug for cerebral ischemia. Besides, this research provides an alternative cell model for penumbra ECs study. PMID:28367097

  6. Primates exposed to cocaine in utero display reduced density and number of cerebral cortical neurons.

    PubMed

    Lidow, M S; Song, Z M

    2001-07-02

    This study examined the effects of cocaine use during the second trimester of pregnancy on cerebral neocortical volume and density, and total number of neocortical neurons and glia in offspring. We also evaluated the extent of postnatal recovery of cytoarchitectural abnormalities previously observed in the neocortex of two-month-old primates born from cocaine-treated mothers (Lidow [1995] Synapse 21:332-334). Pregnant monkeys received cocaine orally (20 mg/kg/day) from the 40th to 102nd days of pregnancy (embryonic day [E]40-E102). On E64 and E65, the animals were injected with [(3)H]thymidine. Cerebral hemispheres of the offspring were examined at three years of age. We found a reduction in the neocortical volume and density and total number of neocortical neurons. The observed reduction in neuronal number within the neocortex was not accounted for by the increase in the number of neurons in the white matter of cocaine-exposed animals, because the number of these "extra" neurons was equal to only half that of missing neurons. We detected no significant changes in the number of neocortical glia. The cytoarchitectural abnormalities in the neocortex of prenatally cocaine-exposed three-year-old monkeys closely resembled previously described neocortical abnormalities in similarly exposed two-month-old animals: the neocortex lacked a discernible lamination; the majority of the cells labeled by [(3)H]thymidine injected during neocortical neurogenesis did not reach their proper position within the cortical plate. Therefore, postnatal maturation is not associated with significant improvement in neocortical organization in primates prenatally exposed to cocaine. There was, however, a postnatal recovery of low glial fibrillary acidic protein (GFAP) immunoreactivity previously observed in 2-month-old cocaine-exposed animals.

  7. Ccm3, a gene associated with cerebral cavernous malformations, is required for neuronal migration.

    PubMed

    Louvi, Angeliki; Nishimura, Sayoko; Günel, Murat

    2014-03-01

    Loss of function of cerebral cavernous malformation 3 (CCM3) results in an autosomal dominant cerebrovascular disorder. Here, we uncover a developmental role for CCM3 in regulating neuronal migration in the neocortex. Using cell type-specific gene inactivation in mice, we show that CCM3 has both cell autonomous and cell non-autonomous functions in neural progenitors and is specifically required in radial glia and newly born pyramidal neurons migrating through the subventricular zone, but not in those migrating through the cortical plate. Loss of CCM3 function leads to RhoA activation, alterations in the actin and microtubule cytoskeleton affecting neuronal morphology, and abnormalities in laminar positioning of primarily late-born neurons, indicating CCM3 involvement in radial glia-dependent locomotion and possible interaction with the Cdk5/RhoA pathway. Thus, we identify a novel cytoplasmic regulator of neuronal migration and demonstrate that its inactivation in radial glia progenitors and nascent neurons produces severe malformations of cortical development.

  8. [Cold inducible RNA-binding protein inhibits hippocampal neuronal apoptosis under hypothermia by regulating redox system].

    PubMed

    Li, Jing-Hui; Zhang, Xue; Meng, Yu; Li, Chang-Sheng; Ji, Hong; Yang, Huan-Min; Li, Shi-Ze

    2015-08-25

    In this study, we intend to confirm our hypothesis that cold inducible RNA-binding protein (CIRP) can inhibit neuronal apoptosis through suppressing the formation of oxygen free radicals under hypothermia. Primary rat hippocampal neurons were isolated and cultured in vitro, and were divided into five groups: (1) normal control group (37 °C), (2) cells infected by empty viral vector group, (3) CIRP over-expressed group, (4) CIRP knock-down group, and (5) hypothermia control group. Cells in groups 2-5 were cultured under 32 °C, 5% CO2. Apoptosis of hippocampal neurons were detected by Annexin V-FITC/PI staining and flow cytometry; Expression of CIRP was determined by Western blot; Redox-related parameters (T-AOC, GSH-Px, SOD, MDA) were detected by ELISA kits. Results showed that CIRP expression levels were significantly increased (P < 0.01) and the apoptotic rates were significantly decreased (P < 0.01) in hypothermia control group and CIRP over-expressed group when compared with normal control group. On the other hand, the apoptotic rate was significantly increased (P < 0.05) in CIRP knock-down group compared with that in hypothermia control group. The levels of redox parameters in hypothermia control group and CIRP over-expressed group were significantly changed in comparison with those in normal control group, CIRP knock-down group and empty viral vector infected group, respectively (P < 0.05 or P < 0.01). These results suggest that up-regulation of CIRP by hypothermia treatment can protect the neuron from apoptosis through suppressing the formation of oxygen free radicals.

  9. Zinc Deficiency Induces Apoptosis via Mitochondrial p53- and Caspase-Dependent Pathways in Human Neuronal Precursor Cells

    ERIC Educational Resources Information Center

    Seth, Rohit; Corniola, Rikki S.; Gower-Winter, Shannon D.; Morgan, Thomas J., Jr.; Bishop, Brian; Levenson, Cathy W.

    2015-01-01

    Previous studies have shown that zinc deficiency leads to apoptosis of neuronal precursor cells in vivo and in vitro. In addition to the role of p53 as a nuclear transcription factor in zinc deficient cultured human neuronal precursors (NT-2), we have now identified the translocation of phosphorylated p53 to the mitochondria and p53-dependent…

  10. Effect of Ginkgo biloba extract on apoptosis of brain tissues in rats with acute cerebral infarction and related gene expression.

    PubMed

    Wu, C; Zhao, X; Zhang, X; Liu, S; Zhao, H; Chen, Y

    2015-06-11

    We investigated the effect of Ginkgo biloba extract on apoptosis of brain tissues in rats with acute cerebral infarction and apoptosis-related gene expression. Rat models of acute cerebral infarction were constructed using the suture method, and randomly divided into the control group, model, and treatment groups. In the treatment group, 4 mg/kg G. biloba extract was intravenously injected into the rat tail vein. Phosphate-buffered saline solution was injected in the model group. Seventy-two hours after treatment, rats were euthanized, and brain tissues were removed to analyze the changes in caspase-3, B-cell lymphoma 2 (Bcl-2), and Bcl-2-associated X protein (Bax) mRNA and protein levels, and variation in brain tissue cells' apoptosis indices was measured. Compared with the control group, the model and treatment groups showed significantly upregulated caspase-3, Bcl-2, and Bax mRNA and protein levels in brain tissues, but remarkably downregulated Bcl-2 mRNA and protein levels (P < 0.05). After treatment, in treatment group brain tissues, caspase-3 and Bax mRNA and protein levels were significantly lower than those in the model group, while Bcl-2 mRNA and protein levels were higher than that in the model group (P < 0.05). The model and treatment groups showed increased cell apoptosis indices of brain tissues compared to the control group; after treatment, the apoptosis index in the treatment group was significantly downregulated compared with that in the model group (P < 0.05). In conclusion, G. biloba extract significantly reduced apoptosis in rat brain tissue cells with acute cerebral infarction and thus protected brain tissues.

  11. In Vitro, Ex Vivo and In Vivo Techniques to Study Neuronal Migration in the Developing Cerebral Cortex

    PubMed Central

    Azzarelli, Roberta; Oleari, Roberto; Lettieri, Antonella; Andre', Valentina; Cariboni, Anna

    2017-01-01

    Neuronal migration is a fundamental biological process that underlies proper brain development and neuronal circuit formation. In the developing cerebral cortex, distinct neuronal populations, producing excitatory, inhibitory and modulatory neurotransmitters, are generated in different germinative areas and migrate along various routes to reach their final positions within the cortex. Different technical approaches and experimental models have been adopted to study the mechanisms regulating neuronal migration in the cortex. In this review, we will discuss the most common in vitro, ex vivo and in vivo techniques to visualize and study cortical neuronal migration. PMID:28448448

  12. Effects of melatonin on streptozotocin-induced retina neuronal apoptosis in high blood glucose rat.

    PubMed

    Li, Xiaoyan; Zhang, Maonian; Tang, Weiqiang

    2013-03-01

    One of the main pathological symptoms of early diabetic retinal neuropathy is retina neuronal apoptosis. In the present work we investigated the effects of indoleamine hormone melatonin, a powerful free radical scavenger, on streptozotocin-induced retina neuronal cell apoptosis in high blood glucose rat. After melatonin treatment (10 mg/kg/day), tunel detection was used to monitor the apoptosis rate of neurons in the retinal ganglion cell layer; reversed quantitative PCR was used to measure the mRNA expression of retinal caspase-3, Mn superoxidase dismutase (SOD) and Cu-Zn SOD; and the activities of total SOD (T-SOD) and sub-type SOD was detected using xanthine oxidase enzymatic detection. Our data showed that melatonin treatment leads to a decrease of retinal cell apoptosis and the apoptotic index was (1.67 ± 0.54) % and (7.73 ± 0.95) % at 8 and 12 weeks after treatment. The relative quantitative (RQ) value for caspase-3 mRNA expression was (6.996 ± 1.192) and (7.267 ± 1.178) in melatonin group, which are much lower than the values of diabetic group (12.566 ± 2.272 and (14.297 ± 2.110) at 8 and 12 weeks, respectively) under the same condition. mRNA expression of Mn SOD and Cu-Zn SOD as well as their activities all decreased in the diabetic group compared with the control group. While melatonin treatment induced the expression of Mn SOD mRNA and a continual increase of Mn SOD activity as well as the activity and mRNA expression of Cu-Zn SOD at 12 weeks. Therefore, our results demonstrate that melatonin treatment prevented the decrease in mRNA expression of SOD and the increase in caspase-3 mRNA expression induced by diabetes thus exerts a beneficial effect on retina neuronal apoptosis.

  13. Atrazine Causes Autophagy- and Apoptosis-Related Neurodegenerative Effects in Dopaminergic Neurons in the Rat Nigrostriatal Dopaminergic System

    PubMed Central

    Song, Xiao-Yao; Li, Jia-Nan; Wu, Yan-Ping; Zhang, Bo; Li, Bai-Xiang

    2015-01-01

    Atrazine (2-chloro-4-ethytlamino-6-isopropylamine-1,3,5-triazine; ATR) is widely used as a broad-spectrum herbicide. Animal studies have demonstrated that ATR exposure can cause cell death in dopaminergic neurons. The molecular mechanisms underlying ATR-induced neuronal cell death, however, are unknown. In this study, we investigated the autophagy and apoptosis induced by ATR in dopaminergic neurons in vivo. Wistar rats were administered with ATR at doses of 10, 50 and 100 mg/kg body weight by oral gavage for three months. In terms of histopathology, the expression of autophagy- and apoptosis-related genes as well as proteins related to the Beclin-1/B-cell lymphoma 2 (Bcl-2) autophagy and apoptosis pathways were examined in the rat nigrostriatal dopaminergic system. We observed degenerative micromorphology indicative of neuronal apoptosis and mitochondrial autophagy by electron microscopy in ATR-exposed rat striatum. The rat ventral mesencephalon in the ATR-exposed groups also showed increased expression of Beclin-1, LC3-II, Bax and Caspase-9, and decreased expression of tyrosine hydroxylase (TH), Bcl-xl and Bcl-2. These findings indicate that ATR may induce autophagy- and apoptosis-related changes in doparminergic neurons. Furthermore, this induction may be regulated by the Beclin-1 and Bcl-2 autophagy and apoptosis pathways, and this may help to better understand the mechanism underlying the neurotoxicity of ATR. PMID:26075868

  14. Transcriptional landscapes at the intersection of neuronal apoptosis and substance P-induced survival: exploring pathways and drug targets.

    PubMed

    Paparone, S; Severini, C; Ciotti, M T; D'Agata, V; Calissano, P; Cavallaro, S

    2016-01-01

    A change in the delicate equilibrium between apoptosis and survival regulates the neurons fate during the development of nervous system and its homeostasis in adulthood. Signaling pathways promoting or protecting from apoptosis are activated by multiple signals, including those elicited by neurotrophic factors, and depend upon specific transcriptional programs. To decipher the rescue program induced by substance P (SP) in cerebellar granule neurons, we analyzed their whole-genome expression profiles after induction of apoptosis and treatment with SP. Transcriptional pathways associated with the survival effect of SP included genes encoding for proteins that may act as pharmacological targets. Inhibition of one of these, the Myc pro-oncogene by treatment with 10058-F4, reverted in a dose-dependent manner the rescue effect of SP. In addition to elucidate the transcriptional mechanisms at the intersection of neuronal apoptosis and survival, our systems biology-based perspective paves the way towards an innovative pharmacology based on targets downstream of neurotrophic factor receptors.

  15. Arsenic moiety in gallium arsenide is responsible for neuronal apoptosis and behavioral alterations in rats.

    PubMed

    Flora, Swaran J S; Bhatt, Kapil; Mehta, Ashish

    2009-10-15

    Gallium arsenide (GaAs), an intermetallic semiconductor finds widespread applications in high frequency microwave and millimeter wave, and ultra fast supercomputers. Extensive use of GaAs has led to increased exposure to humans working in semiconductor industry. GaAs has the ability to dissociate into its constitutive moieties at physiological pH and might be responsible for the oxidative stress. The present study was aimed at evaluating, the principle moiety (Ga or As) in GaAs to cause neurological dysfunction based on its ability to cause apoptosis, in vivo and in vitro and if this neuronal dysfunction translated to neurobehavioral changes in chronically exposed rats. Result indicated that arsenic moiety in GaAs was mainly responsible for causing oxidative stress via increased reactive oxygen species (ROS) and nitric oxide (NO) generation, both in vitro and in vivo. Increased ROS further caused apoptosis via mitochondrial driven pathway. Effects of oxidative stress were also confirmed based on alterations in antioxidant enzymes, GPx, GST and SOD in rat brain. We noted that ROS induced oxidative stress caused changes in the brain neurotransmitter levels, Acetylcholinesterase and nitric oxide synthase, leading to loss of memory and learning in rats. The study demonstrates for the first time that the slow release of arsenic moiety from GaAs is mainly responsible for oxidative stress induced apoptosis in neuronal cells causing behavioral changes.

  16. Arsenic moiety in gallium arsenide is responsible for neuronal apoptosis and behavioral alterations in rats

    SciTech Connect

    Flora, Swaran J.S. Bhatt, Kapil; Mehta, Ashish

    2009-10-15

    Gallium arsenide (GaAs), an intermetallic semiconductor finds widespread applications in high frequency microwave and millimeter wave, and ultra fast supercomputers. Extensive use of GaAs has led to increased exposure to humans working in semiconductor industry. GaAs has the ability to dissociate into its constitutive moieties at physiological pH and might be responsible for the oxidative stress. The present study was aimed at evaluating, the principle moiety (Ga or As) in GaAs to cause neurological dysfunction based on its ability to cause apoptosis, in vivo and in vitro and if this neuronal dysfunction translated to neurobehavioral changes in chronically exposed rats. Result indicated that arsenic moiety in GaAs was mainly responsible for causing oxidative stress via increased reactive oxygen species (ROS) and nitric oxide (NO) generation, both in vitro and in vivo. Increased ROS further caused apoptosis via mitochondrial driven pathway. Effects of oxidative stress were also confirmed based on alterations in antioxidant enzymes, GPx, GST and SOD in rat brain. We noted that ROS induced oxidative stress caused changes in the brain neurotransmitter levels, Acetylcholinesterase and nitric oxide synthase, leading to loss of memory and learning in rats. The study demonstrates for the first time that the slow release of arsenic moiety from GaAs is mainly responsible for oxidative stress induced apoptosis in neuronal cells causing behavioral changes.

  17. Ketamine induces toxicity in human neurons differentiated from embryonic stem cells via mitochondrial apoptosis pathway

    PubMed Central

    Bosnjak, Zeljko J.; Yan, Yasheng; Canfield, Scott; Muravyeva, Maria Y.; Kikuchi, Chika; Wells, Clive; Corbett, John; Bai, Xiaowen

    2013-01-01

    Ketamine is widely used for anesthesia in pediatric patients. Growing evidence indicates that ketamine causes neurotoxicity in a variety of developing animal models. Our understanding of anesthesia neurotoxicity in humans is currently limited by difficulties in obtaining neurons and performing developmental toxicity studies in fetal and pediatric populations. It may be possible to overcome these challenges by obtaining neurons from human embryonic stem cells (hESCs) in vitro. hESCs are able to replicate indefinitely and differentiate into every cell type. In this study, we investigated the toxic effect of ketamine on neurons differentiated from hESCs. Two-week-old neurons were treated with different doses and durations of ketamine with or without the reactive oxygen species (ROS) scavenger, Trolox. Cell viability, ultrastructure, mitochondrial membrane potential (ΔΨm), cytochrome c distribution within cells, apoptosis, and ROS production were evaluated. Here we show that ketamine induced ultrastructural abnormalities and dose- and time-dependently caused cell death. In addition, ketamine decreased ΔΨm and increased cytochrome c release from mitochondria. Ketamine also increased ROS production and induced differential expression of oxidative stress-related genes. Specifically, abnormal ultrastructural and ΔΨm changes occurred earlier than cell death in the ketamine-induced toxicity process. Furthermore, Trolox significantly decreased ROS generation and attenuated cell death caused by ketamine in a dose-dependent manner. In conclusion, this study illustrates that ketamine time- and dose-dependently induces human neurotoxicity via ROS-mediated mitochondrial apoptosis pathway and that these side effects can be prevented by the antioxidant agent Trolox. Thus, hESC-derived neurons might provide a promising tool for studying anesthetic-induced developmental neurotoxicity and prevention strategies. PMID:22873495

  18. Propofol-induced apoptosis of neurones and oligodendrocytes in fetal and neonatal rhesus macaque brain.

    PubMed

    Creeley, C; Dikranian, K; Dissen, G; Martin, L; Olney, J; Brambrink, A

    2013-06-01

    Exposure of the fetal or neonatal non-human primate (NHP) brain to isoflurane or ketamine for 5 h causes widespread apoptotic degeneration of neurones, and exposure to isoflurane also causes apoptotic degeneration of oligodendrocytes (OLs). The present study explored the apoptogenic potential of propofol in the fetal and neonatal NHP brain. Fetal rhesus macaques at gestational age 120 days were exposed in utero, or postnatal day 6 rhesus neonates were exposed directly for 5 h to propofol anaesthesia (n=4 fetuses; and n=4 neonates) or to no anaesthesia (n=4 fetuses; n=5 neonates), and the brains were systematically evaluated 3 h later for evidence of apoptotic degeneration of neurones or glia. Exposure of fetal or neonatal NHP brain to propofol caused a significant increase in apoptosis of neurones, and of OLs at a stage when OLs were just beginning to myelinate axons. Apoptotic degeneration affected similar brain regions but to a lesser extent than we previously described after isoflurane. The number of OLs affected by propofol was approximately equal to the number of neurones affected at both developmental ages. In the fetus, neuroapoptosis affected particularly subcortical and caudal regions, while in the neonate injury involved neocortical regions in a distinct laminar pattern and caudal brain regions were less affected. Propofol anaesthesia for 5 h caused death of neurones and OLs in both the fetal and neonatal NHP brain. OLs become vulnerable to the apoptogenic action of propofol when they are beginning to achieve myelination competence.

  19. PBDE-209 exposure damages learning and memory ability in rats potentially through increased autophagy and apoptosis in the hippocampus neuron.

    PubMed

    Sun, Wen; Du, Lili; Tang, Wenting; Kuang, Liyun; Du, Peili; Chen, Jingsi; Chen, Dunjin

    2017-03-01

    This study is to investigate the neurotoxicity of PBDE-209 during pregnancy through autophagy and apoptosis in the fetal hippocampus neuron. The autophagy protein levels of LC3-II and Beclin-1 were significantly higher in hippocampus tissue and neuron, while P62 protein were lower. Apoptosis protein Cleaved Caspase-3 and Cleaved PARP was significantly higher in PBDE dose groups and BCL-2 levels in high PBDE dose groups were significantly lower. During the Morris water maze task, the escape latency times of high PBDE dose groups were significantly longer. PBDE-209-induced autophagy leads to neurons death and inhibition of autophagy reduce PBDE-209-induced apoptotic cell death. These results suggest that exposure of the PBDE-209 during pregnancy increases hippocampal autophagy, decrease neuron viability, and it partly effect apoptosis induced by PBDE-209. All that may contribute to the decline of learning and memory ability in the offspring. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. The cerebral cortex of the pygmy hippopotamus, Hexaprotodon liberiensis (Cetartiodactyla, Hippopotamidae): MRI, cytoarchitecture, and neuronal morphology.

    PubMed

    Butti, Camilla; Ewan Fordyce, R; Ann Raghanti, Mary; Gu, Xiaosi; Bonar, Christopher J; Wicinski, Bridget A; Wong, Edmund W; Roman, Jessica; Brake, Alanna; Eaves, Emily; Spocter, Muhammad A; Tang, Cheuk Y; Jacobs, Bob; Sherwood, Chet C; Hof, Patrick R

    2014-04-01

    The structure of the hippopotamus brain is virtually unknown because few studies have examined more than its external morphology. In view of their semiaquatic lifestyle and phylogenetic relatedness to cetaceans, the brain of hippopotamuses represents a unique opportunity for better understanding the selective pressures that have shaped the organization of the brain during the evolutionary process of adaptation to an aquatic environment. Here we examined the histology of the cerebral cortex of the pygmy hippopotamus (Hexaprotodon liberiensis) by means of Nissl, Golgi, and calretinin (CR) immunostaining, and provide a magnetic resonance imaging (MRI) structural and volumetric dataset of the anatomy of its brain. We calculated the corpus callosum area/brain mass ratio (CCA/BM), the gyrencephalic index (GI), the cerebellar quotient (CQ), and the cerebellar index (CI). Results indicate that the cortex of H. liberiensis shares one feature exclusively with cetaceans (the lack of layer IV across the entire cerebral cortex), other features exclusively with artiodactyls (e.g., the morphologiy of CR-immunoreactive multipolar neurons in deep cortical layers, gyrencephalic index values, hippocampus and cerebellum volumetrics), and others with at least some species of cetartiodactyls (e.g., the presence of a thick layer I, the pattern of distribution of CR-immunoreactive neurons, the presence of von Economo neurons, clustering of layer II in the occipital cortex). The present study thus provides a comprehensive dataset of the neuroanatomy of H. liberiensis that sets the ground for future comparative studies including the larger Hippopotamus amphibius. Copyright © 2014 Wiley Periodicals, Inc.

  1. Cellullar insights into cerebral cortical development: focusing on the locomotion mode of neuronal migration

    PubMed Central

    Kawauchi, Takeshi

    2015-01-01

    The mammalian brain consists of numerous compartments that are closely connected with each other via neural networks, comprising the basis of higher order brain functions. The highly specialized structure originates from simple pseudostratified neuroepithelium-derived neural progenitors located near the ventricle. A long journey by neurons from the ventricular side is essential for the formation of a sophisticated brain structure, including a mammalian-specific six-layered cerebral cortex. Neuronal migration consists of several contiguous steps, but the locomotion mode comprises a large part of the migration. The locomoting neurons exhibit unique features; a radial glial fiber-dependent migration requiring the endocytic recycling of N-cadherin and a neuron-specific migration mode with dilation/swelling formation that requires the actin and microtubule organization possibly regulated by cyclin-dependent kinase 5 (Cdk5), Dcx, p27kip1, Rac1, and POSH. Here I will introduce the roles of various cellular events, such as cytoskeletal organization, cell adhesion, and membrane trafficking, in the regulation of the neuronal migration, with particular focus on the locomotion mode. PMID:26500496

  2. RP58 regulates the multipolar-bipolar transition of newborn neurons in the developing cerebral cortex.

    PubMed

    Ohtaka-Maruyama, Chiaki; Hirai, Shinobu; Miwa, Akiko; Heng, Julian Ik-Tsen; Shitara, Hiroshi; Ishii, Rie; Taya, Choji; Kawano, Hitoshi; Kasai, Masataka; Nakajima, Kazunori; Okado, Haruo

    2013-02-21

    Accumulating evidence suggests that many brain diseases are associated with defects in neuronal migration, suggesting that this step of neurogenesis is critical for brain organization. However, the molecular mechanisms underlying neuronal migration remain largely unknown. Here, we identified the zinc-finger transcriptional repressor RP58 as a key regulator of neuronal migration via multipolar-to-bipolar transition. RP58(-/-) neurons exhibited severe defects in the formation of leading processes and never shifted to the locomotion mode. Cre-mediated deletion of RP58 using in utero electroporation in RP58(flox/flox) mice revealed that RP58 functions in cell-autonomous multipolar-to-bipolar transition, independent of cell-cycle exit. Finally, we found that RP58 represses Ngn2 transcription to regulate the Ngn2-Rnd2 pathway; Ngn2 knockdown rescued migration defects of the RP58(-/-) neurons. Our findings highlight the critical role of RP58 in multipolar-to-bipolar transition via suppression of the Ngn2-Rnd2 pathway in the developing cerebral cortex.

  3. Layer III neurons control synchronized waves in the immature cerebral cortex.

    PubMed

    Namiki, Shigehiro; Norimoto, Hiroaki; Kobayashi, Chiaki; Nakatani, Kei; Matsuki, Norio; Ikegaya, Yuji

    2013-01-16

    Correlated spiking activity prevails in immature cortical networks and is believed to contribute to neuronal circuit maturation; however, its spatiotemporal organization is not fully understood. Using wide-field calcium imaging from acute whole-brain slices of rat pups on postnatal days 1-6, we found that correlated spikes were initiated in the anterior part of the lateral entorhinal cortex and propagated anteriorly to the frontal cortex and posteriorly to the medial entorhinal cortex, forming traveling waves that engaged almost the entire cortex. The waves were blocked by ionotropic glutamatergic receptor antagonists but not by GABAergic receptor antagonists. During wave events, glutamatergic and GABAergic synaptic inputs were balanced and induced UP state-like depolarization. Magnified monitoring with cellular resolution revealed that the layer III neurons were first activated when the waves were initiated. Consistent with this finding, layer III contained a larger number of neurons that were autonomously active, even under a blockade of synaptic transmission. During wave propagation, the layer III neurons constituted a leading front of the wave. The waves did not enter the parasubiculum; however, in some cases, they were reflected at the parasubicular border and propagated back in the opposite direction. During this reflection process, the layer III neurons in the medial entorhinal cortex maintained persistent activity. Thus, our data emphasize the role of layer III in early network behaviors and provide insight into the circuit mechanisms through which cerebral cortical networks maturate.

  4. An axosomatic and axodendritic multipolar neuron in the lizard cerebral cortex.

    PubMed Central

    Bernabeu, A; Martinez-Guijarro, F J; de la Iglesia, J A; Lopez-Garcia, C

    1994-01-01

    The morphology and synaptic organisation of a type of multipolar neuron of the lizard cerebral cortex were studied by Golgi impregnation, intracellular injection of horseradish peroxidase, electron microscopy, and immunocytochemistry. It is a GABA-immunoreactive interneuron and most likely parvalbumin-immunoreactive. Its conspicuous axonal arbor is characterised by an initial segment arising from the soma or from a juxtasomatic dendritic segment. The initial axon segment ramifies and gives rise to thick myelinated segments that terminate in short unmyelinated branches studded with thick boutons 'en passant' that (1) make axosomatic synapses on bipyramidal neuronal somata and (2) synapse on initial apical dendritic segments of bipyramidal neurons forming climbing-like cartridges. The dendrites extend throughout the thickness of the cortex, receiving synaptic input from a variety of sources of which the most prominent is that of zinc-positive boutons coming from granule cells of the medial cortex. According to its synaptology, this interneuron may play a role in regulating the activity of bipyramidal neurons by both feed-forward and feed-back inhibition mechanisms. From a comparative standpoint, it may be related to the sparsely spiny or nonspiny multipolar neurons of the stratum oriens of the mammalian hippocampus. Images Fig. 1 Fig. 4 Fig. 6 Fig. 7 Fig. 8 PMID:7928645

  5. Chemical interactions with pyramidal neurons in layer 5 of the cerebral cortex: control of pain and anxiety.

    PubMed

    Adams, J D

    2009-01-01

    Pyramidal neurons in layer 5 of the cerebral cortex are involved in learning and memory and have complex connections with other neurons through a very large array of dendrites. These dendrites can switch between long term depression and long term potentiation depending on global summation of various inputs. The plasticity of the input into pyramidal neurons makes the neuronal output variable. Many interneurons in the cerebral cortex and distant neurons in other brain regions are involved in providing input to pyramidal neurons. All of these neurons and interneurons have neurotransmitters that act through receptors to provide input to pyramidal neurons. Serotonin is one of the important neurotransmitters involved with pyramidal neurons and has been implicated in psychosis, psychedelic states and what are called sacred dreams. This review will discuss the various chemicals and receptors that are important with pyramidal neurons including opioids, nicotine, scopolamine, psilocybin, LSD, mescaline, ergot alkaloids, salvinorin A, ergine and other compounds that interact with opioid, nicotinic, muscarinic and serotonergic receptors. The natural compounds provide clues to structure activity relationships with the receptors. It has been postulated that each receptor in the body has a natural agonist and antagonist, in addition to the normal neurotransmitters. It is common for natural antagonists and agonists to be peptides. Various possible peptide structures will be proposed for natural antagonists and agonists at each receptor. Natural antagonists and agonists may provide new ways to explore the functions of pyramidal neurons in normal health and pain management.

  6. The effects of piracetam on heroin-induced CPP and neuronal apoptosis in rats.

    PubMed

    Xu, Peng; Li, Min; Bai, Yanping; Lu, Wei; Ling, Xiaomei; Li, Weidong

    2015-05-01

    Piracetam is a positive allosteric modulator of the AMPA receptor that has been used in the treatment of cognitive disorders for decades. Recent surveys and drug analyses have demonstrated that a heroin mixture adulterated with piracetam has spread rapidly in heroin addicts in China, but its addictive properties and the damage it causes to the central neural system are currently unknown. The effect of piracetam on the reward properties of heroin was assessed by conditioned place preference (CPP). Electron microscopy and radioimmunoassay were used to compare the effects of heroin mixed with equivalent piracetam (HP) and heroin alone on neuronal apoptosis and the levels of beta-endorphin (β-EP) in different brain subregions within the corticolimbic system, respectively. Piracetam significantly enhanced heroin-induced CPP expression while piracetam itself didn't induce CPP. Morphological observations showed that HP-treated rats had less neuronal apoptosis than heroin-treated group. Interestingly, HP normalized the levels of β-EP in the medial prefrontal cortex (mPFC) and core of the nucleus accumbens (AcbC) subregions, in where heroin-treated rats showed decreased levels of β-EP. These results indicate that piracetam potentiate the heroin-induced CPP and protect neurons from heroin-induced apoptosis. The protective role of HP might be related to the restoration of β-EP levels by piracetam. Our findings may provide a potential interpretation for the growing trend of HP abuse in addicts in China. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Effect of serine protease inhibitors on posttraumatic brain injury and neuronal apoptosis.

    PubMed

    Movsesyan, V A; Yakovlev, A G; Fan, L; Faden, A I

    2001-02-01

    N-Tosyl-l-phenylalanyl chloromethyl ketone (TPCK), an inhibitor of chymotrypsin-like serine protease (CSP), prevents DNA fragmentation and apoptotic cell death in certain blood cell lines and was reported to reduce hippocampal neuronal damage caused by cerebral ischemia. We examined the role of CSP on recovery after lateral fluid percussion-induced traumatic brain injury (TBI) in rats, as well as on cell survival in various in vitro models of neuronal cell death. TBI caused significant time-dependent upregulation of CSP activity, but not trypsin-like serine protease activity in injured cortex. Intracerebroventricular administration of TPCK to rats after TBI did not significantly affect deficits of spatial learning but exacerbated motor dysfunction after injury. Moreover, TPCK did not prevent apoptotic neuronal cell death caused by serum/K(+) deprivation or by application of staurosporine or etoposide in cultured rat cerebellar granule cells, rat cortical neurons, or in the human neuroblastoma SH-SY5Y cell line. Instead, at doses from 10 to 100 microM, TPCK was cytotoxic in all cultures tested. Similar results were obtained in cultures treated with another CSP inhibitor, 3,4-dichloroisocoumarin. Cell death caused by CSP inhibitors was neither caspase-dependent nor associated with oligonucleosomal DNA fragmentation. Taken together, these data do not support a neuroprotective role for CSP inhibitors. Rather, they suggest that CSPs may serve an endogenous neuroprotective role, possibly by modulating necrotic cell death. Copyright 2001 Academic Press.

  8. Phospho-Rb mediating cell cycle reentry induces early apoptosis following oxygen-glucose deprivation in rat cortical neurons.

    PubMed

    Yu, Ying; Ren, Qing-Guo; Zhang, Zhao-Hui; Zhou, Ke; Yu, Zhi-Yuan; Luo, Xiang; Wang, Wei

    2012-03-01

    The aim of this study was to investigate the relationship between cell cycle reentry and apoptosis in cultured cortical neurons following oxygen-glucose deprivation (OGD). We found that the percentage of neurons with BrdU uptake, TUNEL staining, and colocalized BrdU uptake and TUNEL staining was increased relative to control 6, 12 and 24 h after 1 h of OGD. The number of neurons with colocalized BrdU and TUNEL staining was decreased relative to the number of TUNEL-positive neurons at 24 h. The expression of phosphorylated retinoblastoma protein (phospho-Rb) was significantly increased 6, 12 and 24 h after OGD, parallel with the changes in BrdU uptake. Phospho-Rb and TUNEL staining were colocalized in neurons 6 and 12 h after OGD. This colocalization was strikingly decreased 24 h after OGD. Treatment with the cyclin-dependent kinase inhibitor roscovitine (100 μM) decreased the expression of phospho-Rb and reduced neuronal apoptosis in vitro. These results demonstrated that attempted cell cycle reentry with phosphorylation of Rb induce early apoptosis in neurons after OGD and there must be other mechanisms involved in the later stages of neuronal apoptosis besides cell cycle reentry. Phosphoralated Rb may be an important factor which closely associates aberrant cell cycle reentry with the early stages of neuronal apoptosis following ischemia/hypoxia in vitro, and pharmacological interventions for neuroprotection may be useful directed at this keypoint.

  9. Oxidative stress associated with neuronal apoptosis in experimental models of epilepsy.

    PubMed

    Méndez-Armenta, Marisela; Nava-Ruíz, Concepción; Juárez-Rebollar, Daniel; Rodríguez-Martínez, Erika; Gómez, Petra Yescas

    2014-01-01

    Epilepsy is considered one of the most common neurological disorders worldwide. Oxidative stress produced by free radicals may play a role in the initiation and progression of epilepsy; the changes in the mitochondrial and the oxidative stress state can lead mechanism associated with neuronal death pathway. Bioenergetics state failure and impaired mitochondrial function include excessive free radical production with impaired synthesis of antioxidants. This review summarizes evidence that suggest what is the role of oxidative stress on induction of apoptosis in experimental models of epilepsy.

  10. Insulin-like growth factor binding protein 5 (IGFBP5) mediates methamphetamine-induced dopaminergic neuron apoptosis.

    PubMed

    Qiao, Dongfang; Xu, Jingtao; Le, Cuiyun; Huang, Enping; Liu, Chao; Qiu, Pingming; Lin, Zhoumeng; Xie, Wei-Bing; Wang, Huijun

    2014-11-04

    Overexposure to methamphetamine (METH), a psychoactive drug, induces a variety of adverse effects to the nervous system, including apoptosis of dopaminergic neurons. Insulin-like growth factor binding protein 5 (IGFBP5), a member of insulin-like growth factor (IGF) system, is a pro-apoptotic factor that plays important roles in neuronal apoptosis. To test the hypothesis that IGFBP5 can mediate METH-induced neuronal apoptosis, we examined IGFBP5 mRNA and protein expression changes in PC12 cells exposed to METH (3.0mM) for 24h and in the striatum of rats following 15 mg/kg × 8 intraperitoneal injections of METH at 12h interval. We also checked the effect on neuronal apoptosis after silencing IGFBP5 expression with TUNEL staining and flow cytometry; Western blot was used for detecting the expression of apoptotic markers active-caspase3 and PARP. To elucidate the mechanisms underlying IGFBP5-mediated neuronal apoptosis, we determined the release of cytochrome c (cyto c), an apoptogenic factor, from the mitochondria after METH treatment with or without IGFBP5 knockdown. Our results showed that IGFBP5 expression was increased significantly after METH exposure in PC12 cells and in the METH-treated rats' striatum. Further, METH-exposed PC12 cells exhibited higher apoptosis-positive cell number and activity of caspase3 and PARP compared with control cells, while these changes can be blocked by silencing IGFBP5 expression. In addition, a significant increase of cyto c release from mitochondria after METH exposure was observed and it was inhibited after silencing IGFBP5 expression in PC12 cells. These results indicate that IGFBP5 plays key roles in METH-induced neuronal apoptosis and may be a potential gene target for therapeutics in METH-caused neurotoxicity.

  11. Genes regulated in neurons undergoing transcription-dependent apoptosis belong to signaling pathways rather than the apoptotic machinery.

    PubMed

    Desagher, Solange; Severac, Dany; Lipkin, Alexey; Bernis, Cyril; Ritchie, William; Le Digarcher, Anne; Journot, Laurent

    2005-02-18

    Neuronal apoptosis has been shown to require de novo RNA/protein synthesis. However, very few genes whose expression is necessary for inducing apoptosis have been identified so far. To systematically identify such genes, we have used genome-scale, long oligonucleotide microarrays and characterized the gene expression profile of cerebellar granule neurons in the early phase of apoptosis elicited by KCl deprivation. We identified 368 significantly differentially expressed genes, including most of the genes previously reported to be transcriptionally regulated in this paradigm. In addition, we identified several hundreds of genes whose transcriptional regulation has never been associated with neuronal apoptosis. We used automated Gene Ontology annotation, analysis of promoter sequences, and statistical tools to characterize these regulations. Although differentially expressed genes included some components of the apoptotic machinery, this functional category was not significantly over-represented among regulated genes. On the other hand, categories related to signal transduction were the most significantly over-represented group. This indicates that the apoptotic machinery is mainly constitutive, whereas molecular pathways that lead to the activation of apoptotic components are transcriptionally regulated. In particular, we show for the first time that signaling pathways known to be involved in the control of neuronal survival are regulated at the transcriptional level and not only by post-translational mechanisms. Moreover, our approach provides insights into novel transcription factors and novel mechanisms, such as the unfolded protein response and cell adhesion, that may contribute to the induction of neuronal apoptosis.

  12. Venlafaxine inhibits apoptosis of hippocampal neurons by up-regulating brain-derived neurotrophic factor in a rat depression model

    PubMed Central

    Huang, Xiao; Mao, Yue-Shi; Li, Chao; Wang, Hao; Ji, Jian-Lin

    2014-01-01

    Objective: To study the effect of venlafaxine on the expression of brain-derived neurotrophic factor (BDNF) in rat hippocampal neurons, as well as its inhibitory effect on apoptosis of hippocampal neurons. Methods: Differences in behavioral ability between the depression model group and the Venlafaxine treatment group were observed using behavioral, sucrose-water and open field tests. The rat hippocampal tissue was sliced, stained and observed for BDNF distribution by immunohistochemistry. Apoptosis of hippocampal neurons was detected by TUNEL. BDNF expression in the hippocampal tissue was detected by Western blot. Injury and apoptosis of the hippocampal tissue were observed by electron microscopy. Results: Behavioral test showed that venlafaxine effectively improved the behavioral abilities of depressed rats. Immunohistochemistry showed that venlafaxine markedly increased the BDNF expression in the rat hippocampus. TUNEL showed that venlafaxine markedly inhibited apoptosis of hippocampal neurons, which was also confirmed by electron microscopic observation of the pathologic sections. Conclusion: Venlafaxine improved the expression of BDNF through working on PI3k/PKB/eNOS pathway and repressed the apoptosis of hippocampal neurons. PMID:25197330

  13. Venlafaxine inhibits apoptosis of hippocampal neurons by up-regulating brain-derived neurotrophic factor in a rat depression model.

    PubMed

    Huang, Xiao; Mao, Yue-Shi; Li, Chao; Wang, Hao; Ji, Jian-Lin

    2014-12-01

    The effect of venlafaxine on the expression of brain-derived neurotrophic factor (BDNF) in rat hippocampal neurons was studied, as well as its inhibitory effect on apoptosis of hippocampal neurons. Differences in behavioral ability between the depression model group and the venlafaxine treatment group were observed in behavioral, sucrose-water and open field tests. The rat hippocampal tissue was sliced, stained and observed for BDNF distribution by immunohistochemistry. Apoptosis of hippocampal neurons was detected by TUNEL. BDNF expression in the hippocampal tissue was detected by Western blot. Injury and apoptosis of the hippocampal tissue were observed by electron microscopy. Behavioral test showed that venlafaxine effectively improved the behavioral abilities of depressed rats. Immunohistochemistry showed that venlafaxine markedly increased BDNF expression in the rat hippocampus. TUNEL showed that venlafaxine markedly inhibited apoptosis of hippocampal neurons, which was also confirmed by electron microscopic observation of the pathologic sections. Venlafaxine improved the expression of BDNF by influencing the PI3k/PKB/eNOS pathway and repressed the apoptosis of hippocampal neurons.

  14. Venlafaxine inhibits apoptosis of hippocampal neurons by up-regulating brain-derived neurotrophic factor in a rat depression model.

    PubMed

    Huang, Xiao; Mao, Yue-Shi; Li, Chao; Wang, Hao; Ji, Jian-Lin

    2014-01-01

    To study the effect of venlafaxine on the expression of brain-derived neurotrophic factor (BDNF) in rat hippocampal neurons, as well as its inhibitory effect on apoptosis of hippocampal neurons. Differences in behavioral ability between the depression model group and the Venlafaxine treatment group were observed using behavioral, sucrose-water and open field tests. The rat hippocampal tissue was sliced, stained and observed for BDNF distribution by immunohistochemistry. Apoptosis of hippocampal neurons was detected by TUNEL. BDNF expression in the hippocampal tissue was detected by Western blot. Injury and apoptosis of the hippocampal tissue were observed by electron microscopy. Behavioral test showed that venlafaxine effectively improved the behavioral abilities of depressed rats. Immunohistochemistry showed that venlafaxine markedly increased the BDNF expression in the rat hippocampus. TUNEL showed that venlafaxine markedly inhibited apoptosis of hippocampal neurons, which was also confirmed by electron microscopic observation of the pathologic sections. Venlafaxine improved the expression of BDNF through working on PI3k/PKB/eNOS pathway and repressed the apoptosis of hippocampal neurons.

  15. Apoptosis of supraoptic AVP neurons is involved in the development of central diabetes insipidus after hypophysectomy in rats.

    PubMed

    Wang, Yihua; Zhao, Cuiping; Wang, Zhigang; Wang, Chengwei; Feng, Wenfeng; Huang, Lijin; Zhang, Jialin; Qi, Songtao

    2008-06-25

    It has been reported that various types of axonal injury of hypothalamo-neurohypophyseal tract can result in degeneration of the magnocellular neurons (MCNs) in hypothalamus and development of central diabetes insipidus (CDI). However, the mechanism of the degeneration and death of MCNs after hypophysectomy in vivo is still unclear. This present study was aimed to disclose it and to figure out the dynamic change of central diabetes insipidus after hypophysectomy. The analysis on the dynamic change of daily water consumption (DWC), daily urine volume(DUV), specific gravity of urine(USG) and plasma vasopressin concentration showed that the change pattern of them was triphasic and neuron counting showed that the degeneration of vasopressin neurons began at 10 d, aggravated at 20 d and then stabilized at 30 d after hypophysectomy. There was marked upregulation of cleaved Caspase-3 expression of vasopressin neurons in hypophysectomy rats. A "ladder" pattern of migration of DNA internucleosomal fragments was detected and apoptotic ultrastructure was found in these neurons. There was time correlation among the occurrence of diabetes insipidus, the changes of plasma vasopressin concentration and the degeneration of vasopressin neurons after hypophysectomy. This study firstly demonstrated that apoptosis was involved in degeneration of supraoptic vasopressin neurons after hypophysectomy in vivo and development of CDI. Our study on time course and correlations among water metabolism, degeneration and apoptosis of vasopressin neurons suggested that there should be an efficient therapeutic window in which irreversible CDI might be prevented by anti-apoptosis.

  16. Aspects of the quantitative analysis of neurons in the cerebral cortex.

    PubMed

    Skoglund, T S; Pascher, R; Berthold, C H

    1996-12-28

    We address three problems concerning the quantitative analysis of nerve cell distribution in the cerebral cortex: (i) preparatory tissue deformation (shrinkage); (ii) difficulties in differentiating between small neurons and astroglia; and (iii) the bias introduced by the counting method. We found that staining with Richardson's solution led to no shrinkage in Vibratome-cut sections of aldehyde-fixed rat brains, but did result in staining of the neurons and left the glial cells unstained. This was in striking contrast to Nissl staining which introduced a linear shrinkage of 20-30% and stained all kinds of cortical cells indiscriminately. A computer-based unbiased counting method was implemented by taking advantage of the stereological procedure referred to as the 'optical disector' (Gundersen, H.J.G. (1986) Stereology of arbitrary particles, J. Microsc., 143: 3-45).

  17. Natural apoptosis in developing mice dopamine midbrain neurons and vermal Purkinje cells.

    PubMed

    Martí-Clúa, J

    2016-01-01

    Natural cell death by apoptosis was studied in two neuronal populations of BALB/c, C57BL/6 and B6CBA-Aw-j/A hybrid stock mice: (I) dopaminergic (DA) neurons in choosing coronal levels throughout the anteroposterior extent of the substantia nigra pars compacta (SNc), and (II) Purkinje cells (PCs) in each vermal lobe of the cerebellar cortex. Mice were collected at postnatal day (P) 2 and P14 for the midbrain study, and at P4 and P7 for the analysis of the cerebellum. No DA cells with morphologic criteria for apoptosis were found. Moreover, when the combination of tyrosine hydroxylase and TUNEL or tyrosine hydroxylase and active caspase-3 immunohistochemistry were performed in the same tissue section, no DA cells TUNEL positives or active caspase-3-stained DA neurons were seen. On the other hand, when PCs were considered, data analysis revealed that more dying PCs were observed at P4 than at P7. Values of neuron death were highest in the central lobe; this was followed by the posterior and anterior lobes and then by the inferior lobe. To determine if apoptotic death of PCs is linked to their time-of-origin profiles, pregnant dams were administered with [3H]TdR on embryonic days 11-12, 12-13, 13-14 and 14-15. When TUNEL and [3H]TdR autoradiography or active caspase-3 immunohistochemistry and [3H]TdR autoradiography were combined in the same tissue section, results reveal that the naturally occurring PC death is not related to its time of origin but, rather, is random across age.

  18. Neurosteroid dehydroepiandrosterone interacts with nerve growth factor (NGF) receptors, preventing neuronal apoptosis.

    PubMed

    Lazaridis, Iakovos; Charalampopoulos, Ioannis; Alexaki, Vassilia-Ismini; Avlonitis, Nicolaos; Pediaditakis, Iosif; Efstathopoulos, Paschalis; Calogeropoulou, Theodora; Castanas, Elias; Gravanis, Achille

    2011-04-01

    The neurosteroid dehydroepiandrosterone (DHEA), produced by neurons and glia, affects multiple processes in the brain, including neuronal survival and neurogenesis during development and in aging. We provide evidence that DHEA interacts with pro-survival TrkA and pro-death p75(NTR) membrane receptors of neurotrophin nerve growth factor (NGF), acting as a neurotrophic factor: (1) the anti-apoptotic effects of DHEA were reversed by siRNA against TrkA or by a specific TrkA inhibitor; (2) [(3)H]-DHEA binding assays showed that it bound to membranes isolated from HEK293 cells transfected with the cDNAs of TrkA and p75(NTR) receptors (K(D): 7.4 ± 1.75 nM and 5.6 ± 0.55 nM, respectively); (3) immobilized DHEA pulled down recombinant and naturally expressed TrkA and p75(NTR) receptors; (4) DHEA induced TrkA phosphorylation and NGF receptor-mediated signaling; Shc, Akt, and ERK1/2 kinases down-stream to TrkA receptors and TRAF6, RIP2, and RhoGDI interactors of p75(NTR) receptors; and (5) DHEA rescued from apoptosis TrkA receptor positive sensory neurons of dorsal root ganglia in NGF null embryos and compensated NGF in rescuing from apoptosis NGF receptor positive sympathetic neurons of embryonic superior cervical ganglia. Phylogenetic findings on the evolution of neurotrophins, their receptors, and CYP17, the enzyme responsible for DHEA biosynthesis, combined with our data support the hypothesis that DHEA served as a phylogenetically ancient neurotrophic factor.

  19. Neurosteroid Dehydroepiandrosterone Interacts with Nerve Growth Factor (NGF) Receptors, Preventing Neuronal Apoptosis

    PubMed Central

    Alexaki, Vassilia-Ismini; Avlonitis, Nicolaos; Pediaditakis, Iosif; Efstathopoulos, Paschalis; Calogeropoulou, Theodora; Castanas, Elias; Gravanis, Achille

    2011-01-01

    The neurosteroid dehydroepiandrosterone (DHEA), produced by neurons and glia, affects multiple processes in the brain, including neuronal survival and neurogenesis during development and in aging. We provide evidence that DHEA interacts with pro-survival TrkA and pro-death p75NTR membrane receptors of neurotrophin nerve growth factor (NGF), acting as a neurotrophic factor: (1) the anti-apoptotic effects of DHEA were reversed by siRNA against TrkA or by a specific TrkA inhibitor; (2) [3H]-DHEA binding assays showed that it bound to membranes isolated from HEK293 cells transfected with the cDNAs of TrkA and p75NTR receptors (KD: 7.4±1.75 nM and 5.6±0.55 nM, respectively); (3) immobilized DHEA pulled down recombinant and naturally expressed TrkA and p75NTR receptors; (4) DHEA induced TrkA phosphorylation and NGF receptor-mediated signaling; Shc, Akt, and ERK1/2 kinases down-stream to TrkA receptors and TRAF6, RIP2, and RhoGDI interactors of p75NTR receptors; and (5) DHEA rescued from apoptosis TrkA receptor positive sensory neurons of dorsal root ganglia in NGF null embryos and compensated NGF in rescuing from apoptosis NGF receptor positive sympathetic neurons of embryonic superior cervical ganglia. Phylogenetic findings on the evolution of neurotrophins, their receptors, and CYP17, the enzyme responsible for DHEA biosynthesis, combined with our data support the hypothesis that DHEA served as a phylogenetically ancient neurotrophic factor. PMID:21541365

  20. Neuroprotective effect of a novel Chinese herbal decoction on cultured neurons and cerebral ischemic rats.

    PubMed

    Ip, Fanny Chui-Fun; Zhao, Yu-Ming; Chan, Kim-Wan; Cheng, Elaine Yee-Ling; Tong, Estella Pui-Sze; Chandrashekar, Oormila; Fu, Guang-Miao; Zhao, Zhong-Zhen; Ip, Nancy Yuk-Yu

    2016-11-04

    Historically, traditional Chinese medicine has been widely used to treat stroke. Based on the theory of Chinese medicine and the modern pharmacological knowledge of herbal medicines, we have designed a neuroprotective formula called Post-Stroke Rehabilitation (PSR), comprising seven herbs - Astragalus membranaceus (Fisch.) Bunge, Salvia miltiorrhiza Bunge, Paeonia lactiflora Pall., Cassia obtusifolia L., Ligusticum chuanxiong Hort., Angelica sinensis (Oliv.) Diels, and Glycyrrhiza uralensis Fisch. We aim to examine the neuroprotective activity of PSR in vitro and in vivo, and to explore the underlying molecular mechanisms, to better understand its therapeutic effect and to further optimize its efficacy. PSR extract or vehicle was applied to primary rat neurons to examine their survival effects against N-methyl-D-aspartate (NMDA)-elicited excitotoxicity. Whole-cell patch-clamp recording was conducted to examine the NMDA-induced current in the presence of PSR. ERK- and CREB-activation were revealed by western blot analysis. Furthermore, PSR was tested for CRE promoter activation in neurons transfected with a luciferase reporter. The protective effect of PSR was then studied in the rat middle cerebral artery occlusion (MCAO) model. MCAO rats were either treated with PSR extract or vehicle, and their neurobehavioral deficit and cerebral infarct were evaluated. Statistical differences were analyzed by ANOVA or t-test. PSR prominently reduced the death of cultured neurons caused by NMDA excitotoxicity in a dose-dependent manner, indicating its neuroprotective property. Furthermore, PSR significantly reduced NMDA-evoked current reversibly and activated phosphorylation of ERK and CREB with distinct time courses, with the latter's kinetics slower. PSR also triggered CRE-promoter activity as revealed by the increased expression of luciferase reporter in transfected neurons. PSR effectively reduced cerebral infarct and deficit in neurological behavior in MCAO rats when PSR

  1. Different mechanisms of secondary neuronal damage in thalamic nuclei after focal cerebral ischemia in rats.

    PubMed

    Dihné, Marcel; Grommes, Christian; Lutzenburg, Michael; Witte, Otto W; Block, Frank

    2002-12-01

    After focal cerebral ischemia, depending on its localization and extent, secondary neuronal damage may occur that is remote from the initial lesion. In this study differences in secondary damage of the ventroposterior thalamic nucleus (VPN) and the reticular thalamic nucleus (RTN) were investigated with the use of different ischemia models. Transient middle cerebral artery occlusion (MCAO) leads to cortical infarction, including parts of the basal ganglia such as the globus pallidus, and to widespread edema. Photothrombotic ischemia generates pure cortical infarcts sparing the basal ganglia and with only minor edema. Neuronal degeneration was quantified within the ipsilateral RTN and VPN 14 days after ischemia. Glial reactions were studied with the use of immunohistochemistry. MCAO resulted in delayed neuronal cell loss of the ipsilateral VPN and RTN. Glial activation occurred in both nuclei beginning after 24 hours. Photothrombotic ischemia resulted in delayed neuronal cell loss only within the VPN. Even 2 weeks after photothrombotic ischemia, glial activation could only be seen within the VPN. Pure cortical infarcts after photothrombotic ischemia, without major edema and without effects on the globus pallidus of the basal ganglia, only lead to secondary VPN damage that is possibly due to retrograde degeneration. MCAO, which results in infarction of cortex and globus pallidus and which causes widespread edema, leads to secondary damage in the VPN and RTN. Thus, additional RTN damage may be due to loss of protective GABAergic input from the globus pallidus to the RTN or due to the extensive edema. Retrograde degeneration is not possible because the RTN, in contrast to the VPN, has no efferents to the cortex.

  2. p75 neurotrophin receptor and its novel interaction partner, NIX, are involved in neuronal apoptosis after intracerebral hemorrhage.

    PubMed

    Shen, Jiabing; Chen, Xiaomei; Li, Hongmei; Wang, Yang; Huo, Keke; Ke, Kaifu

    2017-04-01

    Recently, NIX, a pro-apoptotic BH3-only protein, was found to be a novel p75 neurotrophin receptor (p75(NTR)) binding protein by screening a human fetal brain two-hybrid library in our laboratory. We further study the interaction of these two proteins and the possible roles of p75(NTR) and NIX in intracerebral hemorrhage (ICH)-induced neuronal death. Using the split-ubiquitin yeast two-hybrid system, we found that the "Copper" domain in p75(NTR) and the TM region in NIX were sufficient for the interaction of these two proteins. Co-immunoprecipitation and in vitro binding assays demonstrated the direct interaction between p75(NTR) and NIX. NIX protein was stabilized by p75(NTR) at post-translational levels. Moreover, p75(NTR) was able to work together with NIX to promote apoptosis and affected the NIX-induced JNK-p53-Bax pathway in neuronal PC12 cells. Previous work has indicated that p75(NTR) and NIX are induced in neurons in human ICH and the rat ICH model, respectively. We confirm that both p75(NTR) and NIX levels were up-regulated in glutamate-treated primary cortical neurons (a cellular in vitro model for ICH) and in the rat ICH model. Glutamate exposure increased the association between p75(NTR) and NIX and elevated the activation of the JNK-p53-Bax pathway and neuronal apoptosis; all of these observations were similar in the rat ICH model. Importantly, p75(NTR) and NIX appeared to be involved in cortical neuronal apoptosis, because knockdown of p75(NTR) or NIX not only inhibited the JNK pathway but also impaired neuronal apoptosis. Thus, p75(NTR) and NIX may play critical roles in ICH-induced neuronal apoptosis in vitro and in vivo.

  3. 14,15-EET promotes mitochondrial biogenesis and protects cortical neurons against oxygen/glucose deprivation-induced apoptosis

    SciTech Connect

    Wang, Lai; Chen, Man; Yuan, Lin; Xiang, Yuting; Zheng, Ruimao; Zhu, Shigong

    2014-07-18

    Highlights: • 14,15-EET inhibits OGD-induced apoptosis in cortical neurons. • Mitochondrial biogenesis of cortical neurons is promoted by 14,15-EET. • 14,15-EET preserves mitochondrial function of cortical neurons under OGD. • CREB mediates effect of 14,15-EET on mitochondrial biogenesis and function. - Abstract: 14,15-Epoxyeicosatrienoic acid (14,15-EET), a metabolite of arachidonic acid, is enriched in the brain cortex and exerts protective effect against neuronal apoptosis induced by ischemia/reperfusion. Although apoptosis has been well recognized to be closely associated with mitochondrial biogenesis and function, it is still unclear whether the neuroprotective effect of 14,15-EET is mediated by promotion of mitochondrial biogenesis and function in cortical neurons under the condition of oxygen–glucose deprivation (OGD). In this study, we found that 14,15-EET improved cell viability and inhibited apoptosis of cortical neurons. 14,15-EET significantly increased the mitochondrial mass and the ratio of mitochondrial DNA to nuclear DNA. Key makers of mitochondrial biogenesis, peroxisome proliferator activator receptor gamma-coactivator 1 alpha (PGC-1α), nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM), were elevated at both mRNA and protein levels in the cortical neurons treated with 14,15-EET. Moreover, 14,15-EET markedly attenuated the decline of mitochondrial membrane potential, reduced ROS, while increased ATP synthesis. Knockdown of cAMP-response element binding protein (CREB) by siRNA blunted the up-regulation of PGC-1α and NRF-1 stimulated by 14,15-EET, and consequently abolished the neuroprotective effect of 14,15-EET. Our results indicate that 14,15-EET protects neurons from OGD-induced apoptosis by promoting mitochondrial biogenesis and function through CREB mediated activation of PGC-1α and NRF-1.

  4. Effects of activated ACM on expression of signal transducers in cerebral cortical neurons of rats.

    PubMed

    Wang, Xiaojing; Li, Zhengli; Zhu, Changgeng; Li, Zhongyu

    2007-06-01

    To explore the roles of astrocytes in the epileptogenesis, astrocytes and neurons were isolated, purified and cultured in vitro from cerebral cortex of rats. The astrocytes were activated by ciliary neurotrophic factor (CNTF) and astrocytic conditioned medium (ACM) was collected to treat neurons for 4, 8 and 12 h. By using Western blot, the expression of calmodulin dependent protein kinase II (CaMK II), inducible nitric oxide synthase (iNOS) and adenylate cyclase (AC) was detected in neurons. The results showed that the expression of CaMK II, iNOS and AC was increased significantly in the neurons treated with ACM from 4 h to 12 h (P<0.05), and that of iNOS and AC peaked at 8 h and 12 h respectively. It was suggested that there might be some epileptogenic factors in the ACM and such signal pathways as NOS-NO-cGMP, Ca2+/CaM-CaMK II and AC-cAMP-PKA might take part in the signal transduction of epileptogenesis.

  5. Molecular Pathways Underlying Projection Neuron Production and Migration during Cerebral Cortical Development

    PubMed Central

    Ohtaka-Maruyama, Chiaki; Okado, Haruo

    2015-01-01

    Glutamatergic neurons of the mammalian cerebral cortex originate from radial glia (RG) progenitors in the ventricular zone (VZ). During corticogenesis, neuroblasts migrate toward the pial surface using two different migration modes. One is multipolar (MP) migration with random directional movement, and the other is locomotion, which is a unidirectional movement guided by the RG fiber. After reaching their final destination, the neurons finalize their migration by terminal translocation, which is followed by maturation via dendrite extension to initiate synaptogenesis and thereby complete neural circuit formation. This switching of migration modes during cortical development is unique in mammals, which suggests that the RG-guided locomotion mode may contribute to the evolution of the mammalian neocortical 6-layer structure. Many factors have been reported to be involved in the regulation of this radial neuronal migration process. In general, the radial migration can be largely divided into four steps; (1) maintenance and departure from the VZ of neural progenitor cells, (2) MP migration and transition to bipolar cells, (3) RG-guided locomotion, and (4) terminal translocation and dendrite maturation. Among these, many different gene mutations or knockdown effects have resulted in failure of the MP to bipolar transition (step 2), suggesting that it is a critical step, particularly in radial migration. Moreover, this transition occurs at the subplate layer. In this review, we summarize recent advances in our understanding of the molecular mechanisms underlying each of these steps. Finally, we discuss the evolutionary aspects of neuronal migration in corticogenesis. PMID:26733777

  6. Neuroprotective effect of Momordica charantia in global cerebral ischemia and reperfusion induced neuronal damage in diabetic mice.

    PubMed

    Malik, Zafar Ahmad; Singh, Manjeet; Sharma, P L

    2011-01-27

    Momordica charantia L. (Cucurbitaceae) fruits have been used traditionally for centuries, especially for treating diabetes and associated complications. The present study was performed to evaluate neuroprotective effect of lyophilized M. charantia fruit juice against global cerebral ischemia and reperfusion induced neuronal injury in diabetic mice. Global cerebral ischemia induced by occluding both common carotid arteries for 10 min followed by 24 h reperfusion was used to induce neuronal injury. Ischemia-reperfusion induced neuronal injury was evaluated in terms of cerebral infarct size, generation of free radicals measured as thiobarbaturic acid reactive substances (TBARS), and neurological functions measured as short term memory and motor activity. The cerebral oxidative stress and damage, and neurological deficits were dose dependently attenuated by pre-treatment with the lyophilized M. charantia juice (200-800 mg/kg, p.o., o.d.). Moreover, M. charantia also exhibited dose dependent antihyperglycemic activity in diabetic mice. These results suggest that M. charantia has potent neuroprotective activity against global cerebral ischemia-reperfusion induced neuronal injury and consequent neurological deficits in diabetic mice. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  7. Multichannel optical brain imaging to separate cerebral vascular, tissue metabolic, and neuronal effects of cocaine

    NASA Astrophysics Data System (ADS)

    Ren, Hugang; Luo, Zhongchi; Yuan, Zhijia; Pan, Yingtian; Du, Congwu

    2012-02-01

    Characterization of cerebral hemodynamic and oxygenation metabolic changes, as well neuronal function is of great importance to study of brain functions and the relevant brain disorders such as drug addiction. Compared with other neuroimaging modalities, optical imaging techniques have the potential for high spatiotemporal resolution and dissection of the changes in cerebral blood flow (CBF), blood volume (CBV), and hemoglobing oxygenation and intracellular Ca ([Ca2+]i), which serves as markers of vascular function, tissue metabolism and neuronal activity, respectively. Recently, we developed a multiwavelength imaging system and integrated it into a surgical microscope. Three LEDs of λ1=530nm, λ2=570nm and λ3=630nm were used for exciting [Ca2+]i fluorescence labeled by Rhod2 (AM) and sensitizing total hemoglobin (i.e., CBV), and deoxygenated-hemoglobin, whereas one LD of λ1=830nm was used for laser speckle imaging to form a CBF mapping of the brain. These light sources were time-sharing for illumination on the brain and synchronized with the exposure of CCD camera for multichannel images of the brain. Our animal studies indicated that this optical approach enabled simultaneous mapping of cocaine-induced changes in CBF, CBV and oxygenated- and deoxygenated hemoglobin as well as [Ca2+]i in the cortical brain. Its high spatiotemporal resolution (30μm, 10Hz) and large field of view (4x5 mm2) are advanced as a neuroimaging tool for brain functional study.

  8. Tissue-type plasminogen activator triggers the synaptic vesicle cycle in cerebral cortical neurons

    PubMed Central

    Wu, Fang; Torre, Enrique; Cuellar-Giraldo, David; Cheng, Lihong; Yi, Hong; Bichler, Edyta K; García, Paul S; Yepes, Manuel

    2015-01-01

    The active zone (AZ) is a thickening of the presynaptic membrane where exocytosis takes place. Chemical synapses contain neurotransmitter-loaded synaptic vesicles (SVs) that at rest are tethered away from the synaptic release site, but after the presynaptic inflow of Ca+2 elicited by an action potential translocate to the AZ to release their neurotransmitter load. We report that tissue-type plasminogen activator (tPA) is stored outside the AZ of cerebral cortical neurons, either intermixed with small clear-core vesicles or in direct contact with the presynaptic membrane. We found that cerebral ischemia-induced release of neuronal tPA, or treatment with recombinant tPA, recruits the cytoskeletal protein βII-spectrin to the AZ and promotes the binding of SVs to βII-spectrin, enlarging the population of SVs in proximity to the synaptic release site. This effect does not require the generation of plasmin and is followed by the recruitment of voltage gated calcium channels (VGCC) to the presynaptic terminal that leads to Ca+2-dependent synapsin I phosphorylation, freeing SVs to translocate to the AZ to deliver their neurotransmitter load. Our studies indicate that tPA activates the SV cycle and induces the structural and functional changes in the synapse that are required for successful neurotransmission. PMID:26126868

  9. Allicin protects auditory hair cells and spiral ganglion neurons from cisplatin - Induced apoptosis.

    PubMed

    Wu, Xianmin; Li, Xiaofei; Song, Yongdong; Li, He; Bai, Xiaohui; Liu, Wenwen; Han, Yuechen; Xu, Lei; Li, Jianfeng; Zhang, Daogong; Wang, Haibo; Fan, Zhaomin

    2017-04-01

    Cisplatin is a broad-spectrum anticancer drug that is commonly used in the clinic. Ototoxicity is one of the major side effects of this drug, which caused irreversible sensorineural hearing loss. Allicin, the main biologically active compound derived from garlic, has been shown to exert various anti-apoptotic and anti-oxidative activities in vitro and in vivo studies. We took advantage of C57 mice intraperitoneally injected with cisplatin alone or with cisplatin and allicin combined, to investigate whether allicin plays a protective role in vivo against cisplatin ototoxicity. The result showed that C57 mice in cisplatin group exhibited increased shift in auditory brainstem response, whereas the auditory fuction of mice in allicin + cisplatin group was protected in most frequencies, which was accordance with observed damages of outer hair cells (OHCs) and spiral ganglion neurons (SGNs) in the cochlea. Allicin markedly protected SGN mitochondria from damage and releasing cytochrome c, and significantly reduced pro-apoptosis factor expressions activated by cisplatin, including Bax, cleaved-caspase-9, cleaved-caspase-3and p53. Furthermore, allicin reduced the level of Malondialdehyde (MDA), but increased the level of superoxide dismutase (SOD). All data suggested that allicin could prevent hearing loss induced by cisplatin effectively, of which allicin protected SGNs from apoptosis via mitochondrial pathway while protected OHCs and supporting cells (SCs) from apoptosis through p53 pathway.

  10. Sugammadex-Enhanced Neuronal Apoptosis following Neonatal Sevoflurane Exposure in Mice

    PubMed Central

    Sun, Zhongliang; Adachi, Yushi U.; Makita, Koshi

    2016-01-01

    In rodents, neonatal sevoflurane exposure induces neonatal apoptosis in the brain and results in learning deficits. Sugammadex is a new selective neuromuscular blockade (NMB) binding agent that anesthesiologists can use to achieve immediate reversal of an NMB with few side effects. Given its molecular weight of 2178, sugammadex is thought to be unable to pass through the blood brain barrier (BBB). Volatile anesthetics can influence BBB opening and integrity. Therefore, we investigated whether the intraperitoneal administration of sugammadex could exacerbate neuronal damage following neonatal 2% sevoflurane exposure via changes in BBB integrity. Cleaved caspase-3 immunoblotting was used to detect apoptosis, and the ultrastructure of the BBB was examined by transmission electron microscopy. Exposure to 2% sevoflurane for 6 h resulted in BBB ultrastructural abnormalities in the hippocampus of neonatal mice. Sugammadex alone without sevoflurane did not induce apoptosis. The coadministration of sugammadex with sevoflurane to neonatal mice caused a significant increase (150%) in neuroapoptosis in the brain compared with 2% sevoflurane. In neonatal anesthesia, sugammadex could influence neurotoxicity together with sevoflurane. Exposure to 2% sevoflurane for 6 h resulted in BBB ultrastructural abnormalities in the hippocampus of neonatal mice. PMID:27895665

  11. Human cerebral cortex Cajal-Retzius neuron: development, structure and function. A Golgi study.

    PubMed

    Marín-Padilla, Miguel

    2015-01-01

    The development, morphology and possible functional activity of the Cajal-Retzius cell of the developing human cerebral cortex are explored herein. The C-RC, of extracortical origin, is the essential neuron of the neocortex first lamina. It receives inputs from afferent fibers that reach the first lamina early in development. Although the origin and function of these original afferent fibers remain unknown, their target is the first lamina sole neuron: the C-RC. This neuron orchestrates the arrival, size and stratification of all pyramidal neurons (of ependymal origin) of the neocortex gray matter. Its axonic terminals spread radially and horizontally throughout the entirety of the first lamina establishing contacts with the dendritic terminals of all gray matter pyramidal cells regardless of size, location and/or eventual functional roles. While the neuron axonic terminals spread radially and horizontally throughout the first lamina, the neuronal' body undergoes progressive developmental dilution and locating any of them in the adult brain become quite difficult. The neuron bodies are probably retained in the older regions of the neocortex while their axonic collaterals will spread throughout its more recent ones and eventually will extend to great majority of the cortical surface. The neocortex first lamina evolution and composition and that of the C-RC are intertwined and mutually interdependent. It is not possible to understand the C-RC evolving morphology without understanding that of the first lamina. The first lamina composition and its structural and functional organizations obtained with different staining methods may be utterly different. These differences have added unnecessary confusion about its nature. The essential emptiness observed in hematoxylin and eosin preparations (most commonly used) contrast sharply with the concentration of dendrites (the cortex' largest) obtained using special (MAP-2) stain for dendrites. Only Golgi preparations

  12. Neuronal apoptosis by HIV-1 Vpr: contribution of proinflammatory molecular networks from infected target cells.

    PubMed

    Guha, Debjani; Nagilla, Pruthvi; Redinger, Carrie; Srinivasan, Alagarsamy; Schatten, Gerald P; Ayyavoo, Velpandi

    2012-06-22

    Human immunodeficiency virus type 1 (HIV-1) induces neuronal dysfunction through host cellular factors and viral proteins including viral protein R (Vpr) released from infected macrophages/microglia. Vpr is important for infection of terminally differentiated cells such as macrophages. The objective of this study was to assess the effect of Vpr in the context of infectious virus particles on neuronal death through proinflammatory cytokines released from macrophages. Monocyte-derived macrophages (MDM) were infected with either HIV-1 wild type (HIV-1wt), Vpr deleted mutant (HIV-1∆Vpr) or mock. Cell lysates and culture supernatants from MDMs were analyzed for the expression and release of proinflammatory cytokines by quantitative reverse transcription-PCR and enzyme-linked immunosorbent assay respectively. Mitogen-activated protein kinases (MAPK) were analyzed in activated MDMs by western blots. Further, the effect of Vpr on neuronal apoptosis was examined using primary neurons exposed to culture supernatants from HIV-1wt, HIV-1∆Vpr or mock-infected MDMs by Annexin-V staining, MTT and Caspase - Glo® 3/7 assays. The role of interleukin (IL)-1β, IL-8 and tumor necrosis factor (TNF)-α on neuronal apoptosis was also evaluated in the presence or absence of neutralizing antibodies against these cytokines. HIV-1∆Vpr-infected MDMs exhibited reduced infection over time and specifically a significant downregulation of IL-1β, IL-8 and TNF-α at the transcriptional and/or protein levels compared to HIV-1wt-infected cultures. This downregulation was due to impaired activation of p38 and stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK) in HIV-1∆Vpr-infected MDMs. The association of SAPK/JNK and p38 to IL-1β and IL-8 production was confirmed by blocking MAPKs that prevented the elevation of IL-1β and IL-8 in HIV-1wt more than in HIV-1∆Vpr-infected cultures. Supernatants from HIV-1∆Vpr-infected MDMs containing lower concentrations of IL-1β, IL-8

  13. Neuronal apoptosis by HIV-1 Vpr: contribution of proinflammatory molecular networks from infected target cells

    PubMed Central

    2012-01-01

    Background Human immunodeficiency virus type 1 (HIV-1) induces neuronal dysfunction through host cellular factors and viral proteins including viral protein R (Vpr) released from infected macrophages/microglia. Vpr is important for infection of terminally differentiated cells such as macrophages. The objective of this study was to assess the effect of Vpr in the context of infectious virus particles on neuronal death through proinflammatory cytokines released from macrophages. Methods Monocyte-derived macrophages (MDM) were infected with either HIV-1 wild type (HIV-1wt), Vpr deleted mutant (HIV-1∆Vpr) or mock. Cell lysates and culture supernatants from MDMs were analyzed for the expression and release of proinflammatory cytokines by quantitative reverse transcription-PCR and enzyme-linked immunosorbent assay respectively. Mitogen-activated protein kinases (MAPK) were analyzed in activated MDMs by western blots. Further, the effect of Vpr on neuronal apoptosis was examined using primary neurons exposed to culture supernatants from HIV-1wt, HIV-1∆Vpr or mock-infected MDMs by Annexin-V staining, MTT and Caspase - Glo® 3/7 assays. The role of interleukin (IL)-1β, IL-8 and tumor necrosis factor (TNF)-α on neuronal apoptosis was also evaluated in the presence or absence of neutralizing antibodies against these cytokines. Results HIV-1∆Vpr-infected MDMs exhibited reduced infection over time and specifically a significant downregulation of IL-1β, IL-8 and TNF-α at the transcriptional and/or protein levels compared to HIV-1wt-infected cultures. This downregulation was due to impaired activation of p38 and stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK) in HIV-1∆Vpr-infected MDMs. The association of SAPK/JNK and p38 to IL-1β and IL-8 production was confirmed by blocking MAPKs that prevented the elevation of IL-1β and IL-8 in HIV-1wt more than in HIV-1∆Vpr-infected cultures. Supernatants from HIV-1∆Vpr-infected MDMs containing lower

  14. Inhibition of neuronal nitric oxide synthase improves microregional O2 balance in cerebral ischemia-reperfusion.

    PubMed

    Chi, Oak Z; Rah, Kang H; Barsoum, Sylviana; Liu, Xia; Weiss, Harvey R

    2015-06-29

    Objectives Return of regional cerebral blood flow (rCBF) in focal cerebral ischaemia may not ensure proper distribution of blood flow to meet metabolic demand. This study was performed to determine how inhibition of neuronal nitric oxide synthase (NOS) during ischaemia-reperfusion would affect microregional O2 supply/consumption balances and their variation. Methods Twenty minutes before middle cerebral artery (MCA) occlusion, a NOS inhibitor 7-nitroindazole (7-NI) 50 mg/kg ip (7-NI group) or vehicle (control group) was administered. At 1 hour of ischaemia and 2 hours of reperfusion, rCBF, the size of cortical infarct and arteriolar and venular O2 saturations (20-60 μm in diameter) using cryomicrospectrophotometry were determined. Results Ischaemia-reperfusion decreased the average venular O2 saturation and the ratio of O2 supply/consumption. But, 7-NI treatment improved the average O2 supply/consumption ratio and venular O2 saturation (57.6 ± 1.3 vs 52.0 ± 3.8%) in ischaemia-reperfusion. The heterogeneity of venular O2 saturations reported as coefficient of variation (CV = 100 × SD/mean) was much smaller in the 7-NI than the control group (8.8 vs 15.5). The number of veins with low O2 saturation ( < 50%) was also smaller with the 7-NI (4/70) than the control group (18/70). The size of cortical infarct was smaller with 7-NI treatment. Discussion Our data suggest that inhibition of neuronal NOS by 7-NI improved microregional O2 balance in the ischaemic-reperfused cortex (IR-C). The improvement in microregional O2 balance could be one of the contributing factors to the reduced size of cortical infarct.

  15. Caspase-mediated apoptosis in neuronal excitotoxicity triggered by nitric oxide.

    PubMed Central

    Leist, M.; Volbracht, C.; Kühnle, S.; Fava, E.; Ferrando-May, E.; Nicotera, P.

    1997-01-01

    BACKGROUND: Excitotoxicity and excess generation of nitric oxide (NO) are believed to be fundamental mechanisms in many acute and chronic neurodegenerative disorders. Disturbance of Ca2+ homeostasis and protein nitration/nitrosylation are key features in such conditions. Recently, a family of proteases collectively known as caspases has been implicated as common executor of a variety of death signals. In addition, overactivation of poly-(ADP-ribose) polymerase (PARP) has been observed in neuronal excitotoxicity. We therefore designed this study to investigate whether triggering of caspase activity and/or activation of PARP played a role in cerebellar granule cell (CGC) apoptosis elicited by peroxynitrite (ONOO-) or NO donors. MATERIALS AND METHODS: CGC from wild-type or PARP -/- mice were exposed to various nitric oxide donors. Caspase activation and its implications for membrane alterations, Ca2+ homeostasis, intracellular proteolysis, chromatin degradation, and cell death were investigated. RESULTS: CGC exposed to NO donors undergo apoptosis, which is mediated by excess synaptic release of excitotoxic mediators. This excitotoxic mechanism differs from direct NO toxicity in some other neuronal populations and does not involve PARP activation. Inhibition of caspases with different peptide substrates prevented cell death and the related features, including intracellular proteolysis, chromatin breakdown, and translocation of phosphatidylserine to the outer surface of the cell membrane. Increased Ca2+ influx following N-methyl-D-aspartate (NMDA) receptor (NMDA-R) activation was not inhibited by caspase inhibitors. CONCLUSIONS: In CGC, NO donors elicit apoptosis by a mechanism involving excitotoxic mediators, Ca2+ overload, and subsequent activation of caspases. Images Fig. 4 FIG. 5 FIG. 6 FIG. 7 PMID:9407551

  16. Satratoxin G–Induced Apoptosis in PC-12 Neuronal Cells is Mediated by PKR and Caspase Independent

    PubMed Central

    Islam, Zahidul; Hegg, Colleen C.; Bae, Hee Kyong; Pestka, James J.

    2008-01-01

    Satratoxin G (SG) is a macrocyclic trichothecene mycotoxin produced by Stachybotrys chartarum, a mold suggested to play an etiologic role in damp building-related illnesses. Acute intranasal exposure of mice to SG specifically induces apoptosis in olfactory sensory neurons of the nose. The PC-12 rat pheochromocytoma cell model was used to elucidate potential mechanisms of SG-induced neuronal cell death. Agarose gel electrophoresis revealed that exposure to SG at 10 ng/ml or higher for 48-h induced DNA fragmentation characteristic of apoptosis in PC-12 cells. SG-induced apoptosis was confirmed by microscopic morphology, hypodiploid fluorescence and annexin V-fluorescein isothiocyanate (FITC) uptake. Messenger RNA expression of the proapoptotic genes p53, double-stranded RNA–activated protein kinase (PKR), BAX, and caspase-activated DNAse was significantly elevated from 6 to 48 h after SG treatment. SG also induced apoptosis and proapoptotic gene expression in neural growth factor-differentiated PC-12 cells. Although SG-induced caspase-3 activation, caspase inhibition did not impair apoptosis. Moreover, SG induced nuclear translocation of apoptosis-inducing factor (AIF), a known contributor to caspase-independent neuronal cell death. SG-induced apoptosis was not affected by inhibitors of oxidative stress or mitogen-activated protein kinases but was suppressed by the PKR inhibitor C16 and by PKR siRNA transfection. PKR inhibition also blocked SG-induced apoptotic gene expression and AIF translocation but not caspase-3 activation. Taken together, SG-induced apoptosis in PC-12 neuronal cells is mediated by PKR via a caspase-independent pathway possibly involving AIF translocation. PMID:18535002

  17. Pivotal roles of p53 transcription-dependent and -independent pathways in manganese-induced mitochondrial dysfunction and neuronal apoptosis.

    PubMed

    Wan, Chunhua; Ma, Xa; Shi, Shangshi; Zhao, Jianya; Nie, Xiaoke; Han, Jingling; Xiao, Jing; Wang, Xiaoke; Jiang, Shengyang; Jiang, Junkang

    2014-12-15

    Chronic exposure to excessive manganese (Mn) has been known to lead to neuronal loss and a clinical syndrome resembling idiopathic Parkinson's disease (IPD). p53 plays an integral role in the development of various human diseases, including neurodegenerative disorders. However, the role of p53 in Mn-induced neuronal apoptosis and neurological deficits remains obscure. In the present study, we showed that p53 was critically involved in Mn-induced neuronal apoptosis in rat striatum through both transcription-dependent and -independent mechanisms. Western blot and immunohistochemistrical analyses revealed that p53 was remarkably upregulated in the striatum of rats following Mn exposure. Coincidentally, increased level of cleaved PARP, a hallmark of apoptosis, was observed. Furthermore, using nerve growth factor (NGF)-differentiated PC12 cells as a neuronal cell model, we showed that Mn exposure decreased cell viability and induced apparent apoptosis. Importantly, p53 was progressively upregulated, and accumulated in both the nucleus and the cytoplasm. The cytoplasmic p53 had a remarkable distribution in mitochondria, suggesting an involvement of p53 mitochondrial translocation in Mn-induced neuronal apoptosis. In addition, Mn-induced impairment of mitochondrial membrane potential (ΔΨm) could be partially rescued by pretreatment with inhibitors of p53 transcriptional activity and p53 mitochondrial translocation, Pifithrin-α (PFT-α) and Pifithrin-μ (PFT-μ), respectively. Moreover, blockage of p53 activities with PFT-α and PFT-μ significantly attenuated Mn-induced reactive oxidative stress (ROS) generation and mitochondrial H₂O₂ production. Finally, we observed that pretreatment with PFT-α and PFT-μ ameliorated Mn-induced apoptosis in PC12 cells. Collectively, these findings implicate that p53 transcription-dependent and -independent pathways may play crucial roles in the regulation of Mn-induced neuronal death.

  18. Ammonia prevents glutamate-induced but not low K(+)-induced apoptosis in cerebellar neurons in culture.

    PubMed

    Llansola, M; Boscá, L; Felipo, V; Hortelano, S

    2003-01-01

    Cultured rat cerebellar granule neurons are widely used as a model system for studying neuronal apoptosis. Either low K(+) (5 mM) or low concentrations of glutamate (1-10 microM) induce apoptosis in cerebellar neurons in culture. However, the molecular mechanism(s) involved remain unclear. We show that long-term treatment with ammonia prevents glutamate-induced but not low K(+)-induced apoptosis in cerebellar neurons, as assessed by measuring DNA fragmentation and activation of caspase 3. Ammonia prevented glutamate-induced increase of intracellular calcium, depolarization of the inner mitochondrial membrane, release of cytochrome c to the cytosol, activation of caspase 3 and fragmentation of DNA. However, ammonia did not prevent low K(+)-induced activation of caspase 3 and fragmentation of DNA. These results indicate that the initial steps involved in the induction of apoptosis by low K(+) or by glutamate are different and that ammonia prevents glutamate-induced apoptosis by reducing glutamate-induced rise of intracellular Ca(2+), thus avoiding the activation of subsequent events of the apoptotic process.

  19. Sericin can reduce hippocampal neuronal apoptosis by activating the Akt signal transduction pathway in a rat model of diabetes mellitus☆

    PubMed Central

    Chen, Zhihong; He, Yaqiang; Song, Chengjun; Dong, Zhijun; Su, Zhejun; Xue, Jingfeng

    2012-01-01

    In the present study, a rat model of type 2 diabetes mellitus was established by continuous peritoneal injection of streptozotocin. Following intragastric perfusion of sericin for 35 days, blood glucose levels significantly reduced, neuronal apoptosis in the hippocampal CA1 region decreased, hippocampal phosphorylated Akt and nuclear factor kappa B expression were enhanced, but Bcl-xL/Bcl-2 associated death promoter expression decreased. Results demonstrated that sericin can reduce hippocampal neuronal apoptosis in a rat model of diabetes mellitus by regulating abnormal changes in the Akt signal transduction pathway. PMID:25767499

  20. Sciatic nerve injury induces apoptosis of dorsal root ganglion satellite glial cells and selectively modifies neurosteroidogenesis in sensory neurons.

    PubMed

    Schaeffer, Véronique; Meyer, Laurence; Patte-Mensah, Christine; Eckert, Anne; Mensah-Nyagan, Ayikoe G

    2010-01-15

    Neurosteroids are synthesized either by glial cells, by neurons, or within the context of neuron-glia cross-talk. Various studies suggested neurosteroid involvement in the control of neurodegeneration but there is no evidence showing that the natural protection of nerve cells against apoptosis directly depends on their own capacity to produce neuroprotective neurosteroids. Here, we investigated the interactions between neurosteroidogenesis and apoptosis occurring in sensory structures of rats subjected to neuropathic pain generated by sciatic nerve chronic constriction injury (CCI). Using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), we observed no apoptotic cells in the spinal cord up to 30 days after CCI although pain symptoms such as mechano-allodynia, thermal and mechanical hyperalgesia were evidenced with the Hargreaves's behavioral and von Frey filament tests. In contrast, double-labeling experiments combining TUNEL and immunostaining with antibodies against glutamine synthetase or neuronal nuclei protein revealed apoptosis occurrence in satellite glial cells (SGC) (not in neurons) of CCI rat ipsilateral dorsal root ganglia (DRG) at day 30 after injury. Pulse-chase experiments coupled with high performance liquid chromatography and flow scintillation detection showed that, among numerous biosynthetic pathways converting [(3)H]pregnenolone into various [(3)H]neurosteroids, only [(3)H]estradiol formation was selectively modified and upregulated in DRG of CCI rats. Consistently, immunohistochemical investigations localized aromatase (estradiol-synthesizing enzyme) in DRG neurons but not in SGC. Pharmacological inhibition of aromatase caused apoptosis of CCI rat DRG neurons. Altogether, our results suggest that endogenously produced neurosteroids such as estradiol may be pivotal for the protection of DRG sensory neurons against sciatic nerve CCI-induced apoptosis.

  1. Tissue-type plasminogen activator induces synaptic vesicle endocytosis in cerebral cortical neurons.

    PubMed

    Yepes, M; Wu, F; Torre, E; Cuellar-Giraldo, D; Jia, D; Cheng, L

    2016-04-05

    The release of the serine proteinase tissue-type plasminogen activator (tPA) from the presynaptic terminal of cerebral cortical neurons plays a central role in the development of synaptic plasticity, adaptation to metabolic stress and neuronal survival. Our earlier studies indicate that by inducing the recruitment of the cytoskeletal protein βII-spectrin and voltage-gated calcium channels to the active zone, tPA promotes Ca(2+)-dependent translocation of synaptic vesicles (SVs) to the synaptic release site where they release their load of neurotransmitters into the synaptic cleft. Here we used a combination of in vivo and in vitro experiments to investigate whether this effect leads to depletion of SVs in the presynaptic terminal. Our data indicate that tPA promotes SV endocytosis via a mechanism that does not require the conversion of plasminogen into plasmin. Instead, we show that tPA induces calcineurin-mediated dynamin I dephosphorylation, which is followed by dynamin I-induced recruitment of the actin-binding protein profilin II to the presynaptic membrane, and profilin II-induced F-actin formation. We report that this tPA-induced sequence of events leads to the association of newly formed SVs with F-actin clusters in the endocytic zone. In summary, the data presented here indicate that following the exocytotic release of neurotransmitters tPA activates the mechanism whereby SVs are retrieved from the presynaptic membrane and endocytosed to replenish the pool of vesicles available for a new cycle of exocytosis. Together, these results indicate that in murine cerebral cortical neurons tPA plays a central role coupling SVs exocytosis and endocytosis.

  2. Two Separate Subtypes of Early Non-Subplate Projection Neurons in the Developing Cerebral Cortex of Rodents

    PubMed Central

    Espinosa, Ana; Gil-Sanz, Cristina; Yanagawa, Yuchio; Fairén, Alfonso

    2009-01-01

    The preplate of the cerebral cortex contains projection neurons that connect the cortical primordium with the subpallium. These are collectively named pioneer neurons. After preplate partition, most of these pioneer neurons become subplate neurons. Certain preplate neurons, however, never associate with the subplate but rather with the marginal zone. In the present overview, we propose a novel classification of non-subplate pioneer neurons in rodents into two subtypes. In rats, the neurons of the first subtype are calbindin+ (CB), calretinin+ (CR) and L1+ and are situated in the upper part of the preplate before its partition. Neurons of the second subtype are TAG-1+ and are located slightly deeper to the previous population in the preplate. After the preplate partition, the CB+, CR+ and L1+ neurons remain in the marginal zone whereas TAG-1+ neurons become transiently localized in the upper cortical plate. In mice, by contrast, calcium binding proteins did not label pioneer neurons. We define in mice two subtypes of non-subplate pioneer neurons, either L1+ or TAG-1+/cntn2+. We propose these to be the homologues of the two subtypes of non-subplate pioneer neurons of rats. The anatomical distribution of these neuron populations is similar in rats and mice. The two populations of non-subplate pioneer neurons differ in their axonal projections. Axons of L1+ pioneer neurons project to the ganglionic eminences and the anterior preoptic area, but avoid entering the posterior limb of the internal capsule towards the thalamus. Axons of TAG-1+ pioneer neurons project to the lateral parts of the ganglionic eminences at the early stages of cortical histogenesis examined. PMID:19949463

  3. Human cerebral cortex Cajal-Retzius neuron: development, structure and function. A Golgi study

    PubMed Central

    Marín-Padilla, Miguel

    2015-01-01

    The development, morphology and possible functional activity of the Cajal-Retzius cell of the developing human cerebral cortex are explored herein. The C-RC, of extracortical origin, is the essential neuron of the neocortex first lamina. It receives inputs from afferent fibers that reach the first lamina early in development. Although the origin and function of these original afferent fibers remain unknown, their target is the first lamina sole neuron: the C-RC. This neuron orchestrates the arrival, size and stratification of all pyramidal neurons (of ependymal origin) of the neocortex gray matter. Its axonic terminals spread radially and horizontally throughout the entirety of the first lamina establishing contacts with the dendritic terminals of all gray matter pyramidal cells regardless of size, location and/or eventual functional roles. While the neuron axonic terminals spread radially and horizontally throughout the first lamina, the neuronal’ body undergoes progressive developmental dilution and locating any of them in the adult brain become quite difficult. The neuron bodies are probably retained in the older regions of the neocortex while their axonic collaterals will spread throughout its more recent ones and eventually will extend to great majority of the cortical surface. The neocortex first lamina evolution and composition and that of the C-RC are intertwined and mutually interdependent. It is not possible to understand the C-RC evolving morphology without understanding that of the first lamina. The first lamina composition and its structural and functional organizations obtained with different staining methods may be utterly different. These differences have added unnecessary confusion about its nature. The essential emptiness observed in hematoxylin and eosin preparations (most commonly used) contrast sharply with the concentration of dendrites (the cortex’ largest) obtained using special (MAP-2) stain for dendrites. Only Golgi preparations

  4. Vertical organization of gamma-aminobutyric acid-accumulating intrinsic neuronal systems in monkey cerebral cortex

    SciTech Connect

    DeFelipe, J.; Jones, E.G.

    1985-12-01

    Light and electron microscopic methods were used to examine the neurons in the monkey cerebral cortex labeled autoradiographically following the uptake and transport of (/sup 3/H)-gamma-aminobutyric acid (GABA). Nonpyramidal cell somata in the sensory-motor areas and primary visual area (area 17) were labeled close to the injection site and at distances of 1 to 1.5 mm beyond the injection site, indicating labeling by retrograde axoplasmic transport. This labeling occurred preferentially in the vertical dimension of the cortex. Prior injections of colchicine, an inhibitor of axoplasmic transport, abolished all labeling of somata except those within the injection site. In each area, injections of superficial layers (I to III) produced labeling of clusters of cell somata in layer V, and injections of the deep layers (V and VI) produced labeling of clusters of cell somata in layers II and III. In area 17, injections of the superficial layers produced dense retrograde cell labeling in three bands: in layers IVC, VA, and VI. Vertically oriented chains of silver grains linked the injection sites with the resulting labeled cell clusters. In all areas, the labeling of cells in the horizontal dimension was insignificant. Electron microscopic examination of labeled neurons confirms that the neurons labeled at a distance from an injection site are nonpyramidal neurons, many with somata so small that they would be mistaken for neuroglial cells light microscopically. They receive few axosomatic synapses, most of which have symmetric membrane thickenings. The vertical chains of silver grains overlie neuronal processes identifiable as both dendrites and myelinated axons, but unmyelinated axons may also be included. The clusters of (/sup 3/H)GABA-labeled cells are joined to one another and to adjacent unlabeled cells by junctional complexes, including puncta adherentia and multi-lamellar cisternal complexes.

  5. Increased apoptosis and hypomyelination in cerebral white matter of macular mutant mouse brain.

    PubMed

    Takikita, Shoichi; Takano, Tomoyuki; Narita, Tsutomu; Maruo, Yoshihiro

    2015-09-01

    Hypomyelination in developing brain is often accompanied by congenital metabolic disorders. Menkes kinky hair disease is an X-linked neurodegenerative disease of impaired copper transport, resulting from a mutation of the Menkes disease gene, a transmembrane copper-transporting p-type ATPase gene (ATP7A). In a macular mutant mouse model, the murine ortholog of Menkes gene (mottled gene) is mutated, and widespread neurodegeneration and subsequent death are observed. Although some biochemical analysis of myelin protein in macular mouse has been reported, detailed histological study of myelination in this mouse model is currently lacking. Since myelin abnormality is one of the neuropathologic findings of human Menkes disease, in this study early myelination in macular mouse brain was evaluated by immunohistochemistry. Two-week-old macular mice and normal littermates were perfused with 4% paraformaldehyde. Immunohistochemical staining of paraffin embedded and vibratome sections was performed using antibodies against either CNPase, cleaved caspase-3 or O4 (marker of immature oligodendrocytes). This staining showed that cerebral myelination in macular mouse was generally hypoplastic and that hypomyelination was remarkable in internal capsule, corpus callosum, and cingulate cortex. In addition, an increased number of cleaved caspase-3 positive cells were observed in corpus callosum and internal capsule. Copper deficiency induced by low copper diet has been reported to induce oligodendrocyte dysfunction and leads to hypomyelination in this mouse model. Taken together, hypomyelination observed in this study in a mouse model of Menkes disease is assumed to be induced by increased apoptosis of immature oligodendrocytes in developing cerebrum, through deficient intracellular copper metabolism.

  6. Increased apoptosis and hypomyelination in cerebral white matter of macular mutant mouse brain

    PubMed Central

    Takikita, Shoichi; Takano, Tomoyuki; Narita, Tsutomu; Maruo, Yoshihiro

    2015-01-01

    Hypomyelination in developing brain is often accompanied by congenital metabolic disorders. Menkes kinky hair disease is an X-linked neurodegenerative disease of impaired copper transport, resulting from a mutation of the Menkes disease gene, a transmembrane copper-transporting p-type ATPase gene (ATP7A). In a macular mutant mouse model, the murine ortholog of Menkes gene (mottled gene) is mutated, and widespread neurodegeneration and subsequent death are observed. Although some biochemical analysis of myelin protein in macular mouse has been reported, detailed histological study of myelination in this mouse model is currently lacking. Since myelin abnormality is one of the neuropathologic findings of human Menkes disease, in this study early myelination in macular mouse brain was evaluated by immunohistochemistry. Two-week-old macular mice and normal littermates were perfused with 4% paraformaldehyde. Immunohistochemical staining of paraffin embedded and vibratome sections was performed using antibodies against either CNPase, cleaved caspase-3 or O4 (marker of immature oligodendrocytes). This staining showed that cerebral myelination in macular mouse was generally hypoplastic and that hypomyelination was remarkable in internal capsule, corpus callosum, and cingulate cortex. In addition, an increased number of cleaved caspase-3 positive cells were observed in corpus callosum and internal capsule. Copper deficiency induced by low copper diet has been reported to induce oligodendrocyte dysfunction and leads to hypomyelination in this mouse model. Taken together, hypomyelination observed in this study in a mouse model of Menkes disease is assumed to be induced by increased apoptosis of immature oligodendrocytes in developing cerebrum, through deficient intracellular copper metabolism. PMID:26937406

  7. Simulated weightlessness aggravates hypergravity-induced impairment of learning and memory and neuronal apoptosis in rats.

    PubMed

    Sun, Xi-Qing; Xu, Zhi-Peng; Zhang, Shu; Cao, Xin-Sheng; Liu, Ting-Song

    2009-05-16

    It has been demonstrated that altered gravity may lead to impairments in cognitive functions. However, the effect of a combination of hypergravity and weightlessness on cognitive functions is not well understood. In the present study, we report the effects of high sustained hypergravity after 7 days' simulated weightlessness on learning and memory abilities and neuronal apoptosis in rats. In the Y-maze tests, hypergravity (HG) or simulated weightlessness (SW) significantly decreases accuracy, and increases reaction time of rats compared to that of controls. On the contrary, in the passive avoidance test, HG or SW treatment significantly shortens latency and prolongs total time compared to those of controls. In addition, TUNEL staining shows a few apoptotic cells in cortex and hippocampus in the HG, SW and HG+SW groups, and the number of TUNEL positive cells was found to be the most in the HG+SW group. Furthermore, rats with combined HG and SW treatment reveal a synergistic effect in both the Y-maze and the passive avoidance tests, as well as increased neuronal cell death. These findings suggest that simulated weightlessness may exacerbate hypergravity-induced impairment of learning and memory, likely caused by neuronal cell death in rats.

  8. An Up-regulation of IRF-1 After a Spinal Cord Injury: Implications for Neuronal Apoptosis.

    PubMed

    Zhao, Jian; Chen, Chen; Xiao, Jian-Ru; Wei, Hai-Feng; Zhou, Xu-hui; Mao, Xing-Xing; Zhang, Wei-dong; Qian, Rong; Chen, Xin-lei; He, Ming-qing; Yu, Xiao-Wei; Zhao, Jian

    2015-12-01

    IRF-1, a kind of transcription factor, is expressed in many cell types, except in early embryonal cells. IRF-1 has played an essential role in various physiological and pathological processes, including tumor immune surveillance, viral infection, development of immunity system and pro-inflammatory injury. However, the expression and function of IRF-1 in spinal cord injury (SCI) are still unknown. In this study, we have performed an acute SCI model in adult rats and investigated the dynamic changes of IRF-1 expression in the spinal cord. Western blot have shown that IRF-1 protein levels gradually increased, reaching a peak at day 3 and then gradually declined to a normal level at day 14 after SCI. Double immunofluorescence staining showed that IRF-1 immunoreactivity was found in neurons, but not in astrocytes and microglia. Additionally, colocalization of IRF-1/active caspase-3 was detected in neurons. In vitro, IRF-1 depletion, by short interfering RNA, obviously decreases neuronal apoptosis. In conclusion, this is the first description of IRF-1 expression in spinal cord injury. Our results suggested that IRF-1 might play crucial roles in CNS pathophysiology after SCI.

  9. Engulfing Astrocytes Protect Neurons from Contact-Induced Apoptosis following Injury

    PubMed Central

    Lööv, Camilla; Hillered, Lars; Ebendal, Ted; Erlandsson, Anna

    2012-01-01

    Clearing of dead cells is a fundamental process to limit tissue damage following brain injury. Engulfment has classically been believed to be performed by professional phagocytes, but recent data show that non-professional phagocytes are highly involved in the removal of cell corpses in various situations. The role of astrocytes in cell clearance following trauma has however not been studied in detail. We have found that astrocytes actively collect and engulf whole dead cells in an in vitro model of brain injury and thereby protect healthy neurons from bystander cell death. Time-lapse experiments showed that migrating neurons that come in contact with free-floating cell corpses induced apoptosis, while neurons that migrate through groups of dead cells, garnered by astrocytes, remain unaffected. Furthermore, apoptotic cells are present within astrocytes in the mouse brain following traumatic brain injury (TBI), indicating a possible role for astrocytes in engulfment of apoptotic cells in vivo. qRT-PCR analysis showed that members of both ced pathways and Megf8 are expressed in the cell culture, indicating their possible involvement in astrocytic engulfment. Moreover, addition of dead cells had a positive effect on the protein expression of MEGF10, an ortholog to CED1, known to initiate phagocytosis by binding to phosphatidylserine. Although cultured astrocytes have an immense capacity for engulfment, seemingly without adverse effects, the ingested material is stored rather than degraded. This finding might explain the multinuclear astrocytes that are found at the lesion site in patients with various brain disorders. PMID:22461890

  10. Overexpression of SOD1 in transgenic rats protects vulnerable neurons against ischemic damage after global cerebral ischemia and reperfusion.

    PubMed

    Chan, P H; Kawase, M; Murakami, K; Chen, S F; Li, Y; Calagui, B; Reola, L; Carlson, E; Epstein, C J

    1998-10-15

    Transient global cerebral ischemia resulting from cardiac arrest is known to cause selective death in vulnerable neurons, including hippocampal CA1 pyramidal neurons. It is postulated that oxygen radicals, superoxide in particular, are involved in cell death processes. To test this hypothesis, we first used in situ imaging of superoxide radical distribution by hydroethidine oxidation in vulnerable neurons. We then generated SOD1 transgenic (Tg) rats with a five-fold increase in copper zinc superoxide dismutase activity. The Tg rats and their non-Tg wild-type littermates were subjected to 10 min of global ischemia followed by 1 and 3 d of reperfusion. Neuronal damage, as assessed by cresyl violet staining and DNA fragmentation analysis, was significantly reduced in the hippocampal CA1 region, cortex, striatum, and thalamus in SOD1 Tg rats at 3 d, as compared with the non-Tg littermates. There were no changes in the hippocampal CA3 subregion and dentate gyrus, resistant areas in both SOD1 Tg and non-Tg rats. Quantitative analysis of the damaged CA1 subregion showed marked neuroprotection against transient global cerebral ischemia in SOD1 Tg rats. These results suggest that superoxide radicals play a role in the delayed ischemic death of hippocampal CA1 neurons. Our data also indicate that SOD1 Tg rats are useful tools for studying the role of oxygen radicals in the pathogenesis of neuronal death after transient global cerebral ischemia.

  11. Hyperbaric oxygenation alleviates chronic constriction injury (CCI)-induced neuropathic pain and inhibits GABAergic neuron apoptosis in the spinal cord.

    PubMed

    Fu, Huiqun; Li, Fenghua; Thomas, Sebastian; Yang, Zhongjin

    2017-09-15

    Dysfunction of GABAergic inhibitory controls contributes to the development of neuropathic pain. We examined our hypotheses that (1) chronic constriction injury (CCI)-induced neuropathic pain is associated with increased spinal GABAergic neuron apoptosis, and (2) hyperbaric oxygen therapy (HBO) alleviates CCI-induced neuropathic pain by inhibiting GABAergic neuron apoptosis. Male rats were randomized into 3 groups: CCI, CCI+HBO and the control group (SHAM). Mechanical allodynia was tested daily following CCI procedure. HBO rats were treated at 2.4 atmospheres absolute (ATA) for 60min once per day. The rats were euthanized and the spinal cord harvested on day 8 and 14 post-CCI. Detection of GABAergic cells and apoptosis was performed. The percentages of double positive stained cells (NeuN/GABA), cleaved caspase-3 or Cytochrome C in total GABAergic cells or in total NeuN positive cells were calculated. HBO significantly alleviated mechanical allodynia. CCI-induced neuropathic pain was associated with significantly increased spinal apoptotic GABA-positive neurons. HBO considerably decreased these spinal apoptotic cells. Cytochrome-C-positive neurons and cleaved caspase-3-positive neurons were also significantly higher in CCI rats. HBO significantly decreased these positive cells. Caspase-3 mRNA was also significantly higher in CCI rats. HBO reduced mRNA expression of caspase-3. CCI-induced neuropathic pain was associated with increased apoptotic GABAergic neurons induced by activation of key proteins of mitochondrial apoptotic pathways in the dorsal horn of the spinal cord. HBO alleviated CCI-induced neuropathic pain and reduced GABAergic neuron apoptosis. The beneficial effect of HBO may be via its inhibitory role in CCI-induced GABAergic neuron apoptosis by suppressing mitochondrial apoptotic pathways in the spinal cord. Increased apoptotic GABAergic neurons induced by activation of key proteins of mitochondrial apoptotic pathways in the dorsal horn of the spinal

  12. Phosphorylated retinoblastoma protein (p-Rb) is involved in neuronal apoptosis after traumatic brain injury in adult rats.

    PubMed

    Liu, Wei; Liu, Xiaojuan; Yang, Huilin; Zhu, Xinhui; Yi, Hong; Zhu, Xuesong; Zhang, Jie

    2013-04-01

    Phosphorylated retinoblastoma protein (p-Rb), a well identified cell cycle related protein, is involved in regulating the biological functions of various cell types including neurons. One attractive biological function of p-Rb is releasing E2F transcription factor to induce S-phase entry and cellular proliferation of mitotic cells. However, some studies point out that the role of p-Rb in post-mitotic cells such as mature neurons is unique; it may induce cellular apoptosis rather than proliferation via regulating cell cycle reactivation. Up to now, the knowledge of p-Rb function in CNS is still limited. To investigate whether p-Rb is involved in CNS injury and repair, we performed a traumatic brain injury model in adult rats. Up-regulation of p-Rb was observed in the injured brain cortex by western blot analysis and immunohistochemistry staining. Terminal deoxynucleotidyl transferase deoxy-UTP-nick end labeling (TUNEL) and 4',6-diamidino-2-phenylindole (DAPI) staining suggested that p-Rb was relevant to neuronal apoptosis after brain injury. In addition, glutamate excitotoxic model of primary cortex neurons was introduced to further investigate the role of p-Rb in neuronal apoptosis; the result implied p-Rb was associated with cell cycle activation in the apoptotic neurons. Based on our data, we suggested that p-Rb might play an important role in neuronal apoptosis after traumatic brain injury in rat; which might also provide a basis for the further study on its role in regulating cell cycle re-entry in apoptotic neurons, and might gain a novel strategy for the clinical therapy for traumatic brain injury.

  13. NDUFV2 regulates neuronal migration in the developing cerebral cortex through modulation of the multipolar-bipolar transition.

    PubMed

    Chen, Tianda; Wu, Qinwei; Zhang, Yang; Zhang, Dai

    2015-11-02

    Abnormalities during brain development are tightly linked several psychiatric disorders. Mutations in NADH dehydrogenase ubiquinone flavoprotein 2 (NDUFV2) are responsible for schizophrenia, bipolar disorder and Parkinson׳s disease. However, the function of NDUFV2 during brain development remains unclear. Here we reported that ndufv2 is expressed in the developing cerebral cortex. In utero suppression of ndufv2 arrested neuronal migration, leading to accumulation of ectopic neurons in the intermediate zone. ndufv2 inhibition did not affect radial glia scaffold, progenitor cells or neurons survival. However, the loss of ndufv2 impairs neuronal multipolar-bipolar transition in vivo and polarization in vitro. Moreover, ndufv2 affected actin cytoskeleton and tubulin stabilization in cortical neurons. Overall, our findings establish a new NDUFV2 dependent mechanism underlying neuronal migration and psychiatric disorders.

  14. Sequential neuronal and astrocytic changes after transient middle cerebral artery occlusion in the rat.

    PubMed

    Chen, H; Chopp, M; Schultz, L; Bodzin, G; Garcia, J H

    1993-09-01

    The temporal evolution and spatial distribution of ischemic cell injury was investigated after transient middle cerebral artery (MCA) occlusion. Male Wistar rats (n = 61) were subjected to 2 h of MCA occlusion induced by advancing a nylon monofilament into the right internal carotid artery. Animals were killed after different durations of reperfusion, ranging from 4 to 166 h (n = 6-11 for each group). Neuronal injury and astrocytic reaction were evaluated using hematoxylin and eosin (H & E) and glial fibrillary acidic protein (GFAP) immunohistochemistry, respectively. Eosinophilic neurons were detected at 4 h of reperfusion in the basal ganglia, and at 10 h of reperfusion in the cortex. Focal brain infarct developed by 46 h of reperfusion, both in the cortex and the basal ganglia, and the volume remained constant between 46 and 166 h of reperfusion. Significant differences in astrocytic reaction were detected between the lesion and the periphery of the lesion at reperfusion times from 46 to 166 h; GFAP staining decreased in the core of the lesion and increased in the peripheral areas. Our data suggest that, after 2 h of MCA occlusion, brain tissue progresses from isolated neuronal injury to infarct with a time course dependent on anatomical site; and astrocytic reactivity, expressed by GFAP staining, reflects the outcome of the ischemic injury.

  15. Pax6 regulates regional development and neuronal migration in the cerebral cortex.

    PubMed

    Talamillo, Ana; Quinn, Jane C; Collinson, J Martin; Caric, Damira; Price, David J; West, John D; Hill, Robert E

    2003-03-01

    Mutations in the Pax6 gene disrupt telencephalic development, resulting in a thin cortical plate, expansion of proliferative layers, and the absence of the olfactory bulb. The primary defect in the neuronal cell population of the developing cerebral cortex was analysed by using mouse chimeras containing a mixture of wild-type and Pax6-deficient cells. The chimeric analysis shows that Pax6 influences cellular activity throughout corticogenesis. At early stages, Pax6-deficient and wildtype cells segregate into exclusive patches, indicating an inability of different cell genotypes to interact. At later stages, cells are sorted further based on telencephalic domains. Pax6-deficient cells are specifically reduced in the mediocaudal domain of the dorsal telencephalon, indicating a role in regionalization. In addition, Pax6 regulates the process of radial migration of neuronal precursors. Loss of Pax6 particularly affects movement of neuronal precursors at the subventricular zone/intermediate zone boundary at a transitional migratory phase essential for entry into the intermediate zone. We suggest that the primary role of Pax6 is the continual regulation of cell surface properties responsible for both cellular identity and radial migration, defects of which cause regional cell sorting and abnormalities of migration in chimeras.

  16. Neuroprotective effects of NSTyr on cognitive function and neuronal plasticity in rats of chronic cerebral hypoperfusion.

    PubMed

    Lin, Qi; Hai, Jian; Yao, Li-Yun; Lu, Yang

    2010-04-14

    The neuroprotective effects of N-stearoyl-L-tyrosine (NSTyr) on cognitive function and neuronal plasticity during chronic cerebral hypoperfusion (CCH) in rats were investigated. After induction of CCH, NSTyr was administered daily for 3 months intraperitoneally. Cognitive functions were evaluated by Morris water maze and hippocampal long-term potentiation (LTP). Neuropathological changes were examined using light micrograph and Fluoro-Jade B staining. Neuronal plasticity was assessed by measuring the expression of MAP-2, GAP-43 and synaptophysin on hippocampal regions of rats with immunohistochemistry and western blotting. CCH resulted in significant spatial memory impairment and inhibition of LTP, and led to neurodegeneration in the CA1 region of the hippocampus in the model rats compared with the sham-operated rats. In the model rats treated with NSTyr, cognitive function improved. The expression levels of MAP-2 and synaptophysin protein in hippocampal areas in the model rats were less than those in the sham-operated rats, and increased in the model rats treated with NSTyr. However, no statistical significance of GAP-43 expression among the sham, model and NSTyr groups was observed. These data indicate that NSTyr exerts protective effects on cognitive function of rats after CCH, which may be related to the changes of neurodegeneration and neuronal plasticity in the hippocampal area of rats.

  17. Pharmacologic inhibition of reactive gliosis blocks TNF-α-mediated neuronal apoptosis

    PubMed Central

    Livne-Bar, Izhar; Lam, Susy; Chan, Darren; Guo, Xiaoxin; Askar, Idil; Nahirnyj, Adrian; Flanagan, John G; Sivak, Jeremy M

    2016-01-01

    Reactive gliosis is an early pathological feature common to most neurodegenerative diseases, yet its regulation and impact remain poorly understood. Normally astrocytes maintain a critical homeostatic balance. After stress or injury they undergo rapid parainflammatory activation, characterized by hypertrophy, and increased polymerization of type III intermediate filaments (IFs), particularly glial fibrillary acidic protein and vimentin. However, the consequences of IF dynamics in the adult CNS remains unclear, and no pharmacologic tools have been available to target this mechanism in vivo. The mammalian retina is an accessible model to study the regulation of astrocyte stress responses, and their influence on retinal neuronal homeostasis. In particular, our work and others have implicated p38 mitogen-activated protein kinase (MAPK) signaling as a key regulator of glutamate recycling, antioxidant activity and cytokine secretion by astrocytes and related Müller glia, with potent influences on neighboring neurons. Here we report experiments with the small molecule inhibitor, withaferin A (WFA), to specifically block type III IF dynamics in vivo. WFA was administered in a model of metabolic retinal injury induced by kainic acid, and in combination with a recent model of debridement-induced astrocyte reactivity. We show that WFA specifically targets IFs and reduces astrocyte and Müller glial reactivity in vivo. Inhibition of glial IF polymerization blocked p38 MAPK-dependent secretion of TNF-α, resulting in markedly reduced neuronal apoptosis. To our knowledge this is the first study to demonstrate that pharmacologic inhibition of IF dynamics in reactive glia protects neurons in vivo. PMID:27685630

  18. Downregulation of Mfn2 participates in manganese-induced neuronal apoptosis in rat striatum and PC12 cells.

    PubMed

    Liu, Xinhang; Yang, Jianbin; Lu, Chunhua; Jiang, Shengyang; Nie, Xiaoke; Han, Jingling; Yin, Lifeng; Jiang, Junkang

    2017-02-21

    Manganese (Mn) is a widely distributed trace element that is essential for normal brain function and development. However, chronic exposure to excessive Mn has been known to lead to neuronal loss and manganism, a disease with debilitating motor and cognitive deficits, whose clinical syndrome resembling idiopathic Parkinson's disease (IPD). However, the precise molecular mechanism underlying Mn neurotoxicity remains largely unclear. Accumulating evidence indicates that abnormal mitochondrial functionality is an early and causal event in Mn-induced neurodegeneration and apoptosis. Here, we investigated whether Mitofusin 2 (Mfn2), a highly conserved dynamin-related protein (DRP), played a role in the regulation of Mn-induced neuronal apoptosis. We revealed that Mfn2 was significantly dysregulated in rat striatum and PC12 neuronal-like cells following Mn exposure. Western blot analysis revealed that the expression of Mfn2 was remarkably decreased following different concentrations of Mn exposure. Immunohistochemistry analysis confirmed a remarkable downregulation of Mfn2 in rat striatum after Mn exposure. Immunofluorescent staining showed that Mfn2 was expressed predominantly in neurons, and neuronal loss of Mfn2 was associated with the expression of active caspase-3 following Mn exposure. Importantly, overexpression of Mfn2 apparently attenuated Mn-induced neuronal apoptosis. Notably, treatment with caspase-3 inhibitor Ac-DEVD-CH could not rescue Mn-induced downregulation of Mfn2, suggesting that Mn-induced mfn2 occurs prior to neuronal apoptosis. Taken together, these results indicated that down-regulated expression of Mfn2 might contribute to the pathological processes underlying Mn neurotoxicity.

  19. Pivotal roles of p53 transcription-dependent and -independent pathways in manganese-induced mitochondrial dysfunction and neuronal apoptosis

    SciTech Connect

    Wan, Chunhua; Ma, Xa; Shi, Shangshi; Zhao, Jianya; Nie, Xiaoke; Han, Jingling; Xiao, Jing; Wang, Xiaoke; Jiang, Shengyang; Jiang, Junkang

    2014-12-15

    Chronic exposure to excessive manganese (Mn) has been known to lead to neuronal loss and a clinical syndrome resembling idiopathic Parkinson's disease (IPD). p53 plays an integral role in the development of various human diseases, including neurodegenerative disorders. However, the role of p53 in Mn-induced neuronal apoptosis and neurological deficits remains obscure. In the present study, we showed that p53 was critically involved in Mn-induced neuronal apoptosis in rat striatum through both transcription-dependent and -independent mechanisms. Western blot and immunohistochemistrical analyses revealed that p53 was remarkably upregulated in the striatum of rats following Mn exposure. Coincidentally, increased level of cleaved PARP, a hallmark of apoptosis, was observed. Furthermore, using nerve growth factor (NGF)-differentiated PC12 cells as a neuronal cell model, we showed that Mn exposure decreased cell viability and induced apparent apoptosis. Importantly, p53 was progressively upregulated, and accumulated in both the nucleus and the cytoplasm. The cytoplasmic p53 had a remarkable distribution in mitochondria, suggesting an involvement of p53 mitochondrial translocation in Mn-induced neuronal apoptosis. In addition, Mn-induced impairment of mitochondrial membrane potential (ΔΨm) could be partially rescued by pretreatment with inhibitors of p53 transcriptional activity and p53 mitochondrial translocation, Pifithrin-α (PFT-α) and Pifithrin-μ (PFT-μ), respectively. Moreover, blockage of p53 activities with PFT-α and PFT-μ significantly attenuated Mn-induced reactive oxidative stress (ROS) generation and mitochondrial H{sub 2}O{sub 2} production. Finally, we observed that pretreatment with PFT-α and PFT-μ ameliorated Mn-induced apoptosis in PC12 cells. Collectively, these findings implicate that p53 transcription-dependent and -independent pathways may play crucial roles in the regulation of Mn-induced neuronal death. - Highlights: • p53 is robustly

  20. Baicalein Promotes Neuronal and Behavioral Recovery After Intracerebral Hemorrhage Via Suppressing Apoptosis, Oxidative Stress and Neuroinflammation.

    PubMed

    Wei, Ning; Wei, Yinghai; Li, Binru; Pang, Linlin

    2017-01-21

    Intracerebral hemorrhage (ICH) is an important public health problem in neurology, which is not only associated with high mortality but also leading to disability. Yet no satisfactory treatment has been developed. The secondary injury that resulted from a number of self-destructive processes such as neuroinflammation, apoptosis and oxidative stress, is the key factor contributing to ICH-induced brain damage. Baicalein has been proved to improve neuronal functional recovery in rat model of subarachnoid hemorrhage and ischemic brain damage. To investigate the effect of baicalein on ICH and its underlying mechanism, a collagenase-induced ICH rat model was performed. Baicalein treatment significantly decreased neurological severity score at day 1 and 3 after ICH injury. Our results showed that the lesion volume, the brain water content, the expression levels of four pro-inflammatory cytokines (IL-1β, IL-4 and IL-6 and TNF-α) and the numbers of apoptotic cells were reduced significantly in ICH rats receiving baicalein treatment, especially in 50 mg/kg baicalein-treated group. Moreover, baicalein increased SOD and GSH-Px activities and down-regulated MDA level of brain tissues in rats. These results suggested that the therapeutic efficacy of baicalein on repairing brain damage is probably caused by suppressing apoptosis, oxidative stress and neuroinflammation. Baicalein could be developed into a novel drug for clinical treatment of ICH and ICH-related brain injuries.

  1. Monitoring apoptosis and neuronal degeneration by real-time detection of phosphatidylserine externalization using a polarity-sensitive indicator of viability and apoptosis

    PubMed Central

    Kim, Yujin E; Chen, Jeannie; Langen, Ralf; Chan, Jonah R

    2015-01-01

    Applications for noninvasive real-time imaging of apoptosis and neuronal degeneration are hindered by technical limitations in imaging strategies and by existing probes. Monitoring the progression of a cell through apoptosis could provide valuable insight into the temporal events that initiate cell death as well as the potential for rescue of apoptotic cells. We engineered an annexin-based biosensor to function as a polarity-sensitive indicator for viability and apoptosis (known as psIVa) by binding to externalized phosphatidylserine (ps) exposed on apoptotic cell membranes. constructed from a structure-based design strategy, psIVa fluoresces only when bound to ps and remains effectively undetectable in solution. In this paper, we describe protocols for the design, expression, purification and labeling of psIVa as well as for its application in time-lapse imaging of degenerating neurons in culture; the entire protocol can be completed in 2 weeks. the primary advantage of this method is the flexibility to use psIVa, in combination with other probes and without perturbing experimental conditions, to explore the cellular mechanisms involved in apoptosis and degeneration in real time. PMID:20671723

  2. Monitoring apoptosis and neuronal degeneration by real-time detection of phosphatidylserine externalization using a polarity-sensitive indicator of viability and apoptosis.

    PubMed

    Kim, Yujin E; Chen, Jeannie; Langen, Ralf; Chan, Jonah R

    2010-08-01

    Applications for noninvasive real-time imaging of apoptosis and neuronal degeneration are hindered by technical limitations in imaging strategies and by existing probes. Monitoring the progression of a cell through apoptosis could provide valuable insight into the temporal events that initiate cell death as well as the potential for rescue of apoptotic cells. We engineered an annexin-based biosensor to function as a polarity-sensitive indicator for viability and apoptosis (known as pSIVA) by binding to externalized phosphatidylserine (PS) exposed on apoptotic cell membranes. Constructed from a structure-based design strategy, pSIVA fluoresces only when bound to PS and remains effectively undetectable in solution. In this paper, we describe protocols for the design, expression, purification and labeling of pSIVA as well as for its application in time-lapse imaging of degenerating neurons in culture; the entire protocol can be completed in 2 weeks. The primary advantage of this method is the flexibility to use pSIVA, in combination with other probes and without perturbing experimental conditions, to explore the cellular mechanisms involved in apoptosis and degeneration in real time.

  3. In Utero Electroporation: Assay System for Migration of Cerebral Cortical Neurons

    NASA Astrophysics Data System (ADS)

    Tabata, Hidenori; Nakajima, Kazunori

    During the development of the cerebral cortex, the majority of cortical neurons are generated in the ventricular zone (VZ) facing the lateral ventricle and then migrate toward the pial surface to form the highly organized 6-layered cerebral cortex. Detailed profiles of these processes and their molecular mechanisms had been largely unknown because of the absence of an efficient assay system. The in vivo electroporation system was initially devised for use within chick embryos (Funahashi et al., 1999; Itasaki et al., 1999; Momose et al., 1999; Muramatsu et al., 1997), and we and other groups have used that system as a basis for developing an in utero electroporation system, which allows plasmid DNA to be introduced into cortical progenitor cells in developing mouse embryos in the uterus (Fukuchi-Shimogori and Grove, 2001; Saito and Nakatsuji, 2001; Tabata and Nakajima, 2001; Takahashi et al., 2002). In utero electroporation of other sites in the brain, including the hippocampus (Navarro-Quiroga et al., 2007), cerebral basal ganglia (Borrell et al., 2005; Nakahira et al., 2006), cortical hem (Takiguchi-Hayashi et al., 2004), and dorsal thalamus (Bonnin et al., 2007), has recently been reported. Introducing green fluorescent protein (GFP) enables the entire processes of migration and layer formation to be visualized (Ajioka and Nakajima, 2005; Sasaki et al., 2008; Tabata and Nakajima, 2002, 2003), and the role of any gene involved in these processes can be easily assessed by overexpressing the proteins or their mutants (Ohshima et al., 2007), or by knocking down the genes by the RNA interference technique (Bai et al., 2003). Furthermore, the Tet-On/Off system and/or other plasmid- vector-based technologies will expand the potential of the analyses. In this section we review the principles and methods of gene transfer into the cortical wall of mouse embryos by means of the in utero electroporation system.

  4. Glutamate and GABA imbalance promotes neuronal apoptosis in hippocampus after stress

    PubMed Central

    Gao, Jie; Wang, He; Liu, Yuan; Li, Ying-yu; Chen, Can; Liu, Liang-ming; Wu, Ya-min; Li, Sen; Yang, Ce

    2014-01-01

    Background People who experience traumatic events have an increased risk of post-traumatic stress disorder (PTSD). However, PTSD-related pathological changes in the hippocampus and prefrontal cortex remain poorly understood. Material/Methods We investigated the effect of a PTSD-like animal model induced by severe stress. The experimental rats received 20 inescapable electric foot shocks in an enclosed box for a total of 6 times in 3 days. The physiological state (body weight and plasma corticosterone concentrations), emotion, cognitive behavior, brain morphology, apoptosis, and balance of gamma-aminobutyric acid (GABA) and glutamate in the hippocampus and prefrontal cortex were observed. Cell damages were examined with histological staining (HE, Nissl, and silver impregnation), while apoptosis was analyzed with flow cytometry using an Annexin V and propidium iodide (PI) binding and terminal deoxynucleotidyl transferase mediated-dUTP nick end labeling (TUNEL) method. Results In comparison with the sham litter-mates, the stressed rats showed decreased body weight, inhibition of hypothalamic-pituitary-adrenal (HPA) axis activation, increase in freezing response to trauma reminder, hypoactivity and anxiety-like behaviors in elevated plus maze and open field test, poor learning in Morris water maze, and shortened latency in hot-plate test. There were significant damages in the hippocampus but not in the prefrontal cortex. Imbalance between glutamate and GABA was more evident in the hippocampus than in the prefrontal cortex. Conclusions These results suggest that neuronal apoptosis in the hippocampus after severe traumatic stress is related to the imbalance between glutamate and GABA. Such modifications may resemble the profound changes observed in PTSD patients. PMID:24675061

  5. Retinoic acid influences neuronal migration from the ganglionic eminence to the cerebral cortex

    PubMed Central

    Crandall, James E.; Goodman, Timothy; McCarthy, Deirdre M.; Duester, Gregg; Bhide, Pradeep G.; Dräger, Ursula C.; McCaffery, Peter

    2013-01-01

    The ganglionic eminence contributes cells to several forebrain structures including the cerebral cortex, for which it provides GABAergic interneurons. Migration of neuronal precursors from the retinoic-acid rich embryonic ganglionic eminence to the cerebral cortex is known to be regulated by several factors, but retinoic acid has not been previously implicated. We found retinoic acid to potently inhibit cell migration in slice preparations of embryonic mouse forebrains, which was reversed by an antagonist of the dopamine-D2 receptor, whose gene is transcriptionally regulated by retinoic acid. Histonedeacetylase inhibitors, which amplify nuclear receptor-mediated transcription, potentiated the inhibitory effect of retinoic acid. Surprisingly, when retinoic acid signalling was completely blocked with a pan-retinoic acid receptor antagonist, this also decreased cell migration into the cortex, implying that a minimal level of endogenous retinoic acid is necessary for tangential migration. Given these opposing effects of retinoic acid in vitro, the in vivo contribution of retinoic acid to migration was tested by counting GABAergic interneurons in cortices of adult mice with experimental reductions in retinoic acid signalling: a range of perturbations resulted in significant reductions in the numerical density of some GABAergic interneuron subpopulations. These observations suggest functions of retinoic acid in interneuron diversity and organization of cortical excitatory–inhibitory balance. PMID:21895658

  6. Selective Neuronal Nitric Oxide Synthase Inhibitors and the Prevention of Cerebral Palsy

    PubMed Central

    Ji, Haitao; Tan, Sidhartha; Igarashi, Jotaro; Li, Huiying; Derrick, Matthew; Martásek, Pavel; Roman, Linda J.; Vásquez-Vivar, Jeannette; Poulos, Thomas L.; Silverman, Richard B.

    2008-01-01

    Objective To design a new class of selective neuronal nitric oxide synthase (nNOS) inhibitors and demonstrate that administration in a rabbit model for cerebral palsy (CP) prevents hypoxia-ischemia induced deaths and reduces the number of newborn kits exhibiting signs of CP. Methods We used a novel computer-based drug design method called fragment hopping to identify new chemical entities, synthesized them, carried out in vitro enzyme inhibition studies with the three isozymes of NOS and in vivo experiments to monitor cardiovascular effects on pregnant rabbit dams, NOS activity and NOx concentration in fetal brain, and assess neurobehavioral effects on kits born to saline- and compound treated dams. Results The computer-based design led to the development of powerful and highly selective compounds for inhibition of nNOS over the other isozymes. Following maternal administration in a rabbit model of CP, these compounds were found to distribute to fetal brain, to be non-toxic, without cardiovascular effects, inhibit fetal brain NOS activity in vivo, reduce NO concentration in fetal brain, and dramatically ameliorate deaths and number of newborn kits exhibiting signs of CP. Interpretation This approach may lead to new preventive strategies for cerebral palsy. PMID:19235180

  7. Apoptosis of Hippocampal Pyramidal Neurons Is Virus Independent in a Mouse Model of Acute Neurovirulent Picornavirus Infection

    PubMed Central

    Buenz, Eric J.; Sauer, Brian M.; LaFrance-Corey, Reghann G.; Deb, Chandra; Denic, Aleksandar; German, Christopher L.; Howe, Charles L.

    2009-01-01

    Many viruses, including picornaviruses, have the potential to infect the central nervous system (CNS) and stimulate a neuroinflammatory immune response, especially in infants and young children. Cognitive deficits associated with CNS picornavirus infection result from injury and death of neurons that may occur due to direct viral infection or during the immune responses to virus in the brain. Previous studies have concluded that apoptosis of hippocampal neurons during picornavirus infection is a cell-autonomous event triggered by direct neuronal infection. However, these studies assessed neuron death at time points late in infection and during infections that lead to either death of the host or persistent viral infection. In contrast, many neurovirulent picornavirus infections are acute and transient, with rapid clearance of virus from the host. We provide evidence of hippocampal pathology in mice acutely infected with the Theiler’s murine encephalomyelitis picornavirus. We found that CA1 pyramidal neurons exhibited several hallmarks of apoptotic death, including caspase-3 activation, DNA fragmentation, and chromatin condensation within 72 hours of infection. Critically, we also found that many of the CA1 pyramidal neurons undergoing apoptosis were not infected with virus, indicating that neuronal cell death during acute picornavirus infection of the CNS occurs in a non–cell-autonomous manner. These observations suggest that therapeutic strategies other than antiviral interventions may be useful for neuroprotection during acute CNS picornavirus infection. PMID:19608874

  8. ClC-3 Expression and Its Association with Hyperglycemia Induced HT22 Hippocampal Neuronal Cell Apoptosis.

    PubMed

    Fan, Feiyan; Liu, Tao; Wang, Xin; Ren, Dongni; Liu, Hui; Zhang, Pengxing; Wang, Zhen; Liu, Nan; Li, Qian; Tu, Yanyang; Fu, Jianfang

    2016-01-01

    Although apoptosis plays an important role in the development of Diabetic Encephalopathy (DE), the underlying molecular mechanisms remain unclear. With respect to this, the present work aims to study the variation in chloride/proton exchanger ClC-3 expression and its association with HT22 hippocampal neuronal apoptosis under hyperglycemic condition in vitro. The cells were stimulated with added 0, 5, or 25 mM glucose or mannitol for up to 72 hours before assessing the rate of ClC-3 expression, cell viability, and apoptosis. In a consecutive experiment, cells received chloride channel blocker in addition to glucose. The rate of cellular death/apoptosis and viability was measured using Flow Cytometry and MTT assay, respectively. Changes in ClC-3 expression were assessed using immunofluorescence staining and western blot analysis. The results revealed a significant increase in cellular apoptosis and reduction in viability, associated with increased ClC-3 expression in high glucose group. Osmolarity had no role to play. Addition of chloride channel blocker completely abolished this effect. Thus we conclude that, with its increased expression, ClC-3 plays a major role in hyperglycemia induced hippocampal neuronal apoptosis. To strengthen our understanding of this aforesaid association, we conducted an extensive literature search which is presented in this paper.

  9. Glutamate Clearance Is Locally Modulated by Presynaptic Neuronal Activity in the Cerebral Cortex

    PubMed Central

    Armbruster, Moritz; Hanson, Elizabeth

    2016-01-01

    Excitatory amino acid transporters (EAATs) are abundantly expressed by astrocytes, rapidly remove glutamate from the extracellular environment, and restrict the temporal and spatial extent of glutamate signaling. Studies probing EAAT function suggest that their capacity to remove glutamate is large and does not saturate, even with substantial glutamate challenges. In contrast, we report that neuronal activity rapidly and reversibly modulates EAAT-dependent glutamate transport. To date, no physiological manipulation has shown changes in functional glutamate uptake in a nonpathological state. Using iGluSnFr-based glutamate imaging and electrophysiology in the adult mouse cortex, we show that glutamate uptake is slowed up to threefold following bursts of neuronal activity. The slowing of glutamate uptake depends on the frequency and duration of presynaptic neuronal activity but is independent of the amount of glutamate released. The modulation of glutamate uptake is brief, returning to normal within 50 ms after stimulation ceases. Interestingly, the slowing of glutamate uptake is specific to activated synapses, even within the domain of an individual astrocyte. Activity-induced slowing of glutamate uptake, and the increased persistence of glutamate in the extracellular space, is reflected by increased decay times of neuronal NR2A-mediated NMDA currents. These results show that astrocytic clearance of extracellular glutamate is slowed in a temporally and spatially specific manner following bursts of neuronal activity ≥30 Hz and that these changes affect the neuronal response to released glutamate. This suggests a previously unreported form of neuron–astrocyte interaction. SIGNIFICANCE STATEMENT We report the first fast, physiological modulation of astrocyte glutamate clearance kinetics. We show that presynaptic activity in the cerebral cortex increases the persistence of glutamate in the extracellular space by slowing its clearance by astrocytes. Because of

  10. Phrenic nerve afferent activation of neurons in the cat SI cerebral cortex.

    PubMed

    Davenport, Paul W; Reep, Roger L; Thompson, Floyd J

    2010-03-01

    Stimulation of respiratory afferents elicits neural activity in the somatosensory region of the cerebral cortex in humans and animals. Respiratory afferents have been stimulated with mechanical loads applied to breathing and electrical stimulation of respiratory nerves and muscles. It was hypothesized that stimulation of the phrenic nerve myelinated afferents will activate neurons in the 3a and 3b region of the somatosensory cortex. This was investigated in cats with electrical stimulation of the intrathoracic phrenic nerve and C(5) root of the phrenic nerve. The somatosensory cortical response to phrenic afferent stimulation was recorded from the cortical surface, contralateral to the phrenic nerve, ispilateral to the phrenic nerve and with microelectrodes inserted into the cortical site of the surface dipole. Short-latency, primary cortical evoked potentials (1 degrees CEP) were recorded with stimulation of myelinated afferents of the intrathoracic phrenic nerve in the contralateral post-cruciate gyrus of all animals (n = 42). The mean onset and peak latencies were 8.5 +/- 5.7 ms and 21.8 +/- 9.8 ms, respectively. The rostro-caudal surface location of the 1 degrees CEP was found between the rostral edge of the post-cruciate dimple (PCD) and the rostral edge of the ansate sulcus, medio-lateral location was between 2 mm lateral to the sagittal sulcus and the lateral end of the cruciate sulcus. Histological examination revealed that the 1 degrees CEP sites were recorded over areas 3a and 3b of the SI somatosensory cortex. Intracortical activation of 16 neurons with two patterns of neural activity was recorded: (1) short-latency, short-duration activation of neurons and (2) long-latency, long-duration activation of neurons. Short-latency neurons had a mean onset latency of 10.4 +/- 3.1 ms and mean burst duration of 10.1 +/- 3.2 ms. The short-latency units were recorded at an average depth of 1.7 +/- 0.5 mm below the cortical surface. The long-latency neurons had a

  11. Cenpj/CPAP regulates progenitor divisions and neuronal migration in the cerebral cortex downstream of Ascl1

    PubMed Central

    Garcez, Patricia P.; Diaz-Alonso, Javier; Crespo-Enriquez, Ivan; Castro, Diogo; Bell, Donald; Guillemot, François

    2015-01-01

    The proneural factor Ascl1 controls multiple steps of neurogenesis in the embryonic brain, including progenitor division and neuronal migration. Here we show that Cenpj, also known as CPAP, a microcephaly gene, is a transcriptional target of Ascl1 in the embryonic cerebral cortex. We have characterized the role of Cenpj during cortical development by in utero electroporation knockdown and found that silencing Cenpj in the ventricular zone disrupts centrosome biogenesis and randomizes the cleavage plane orientation of radial glia progenitors. Moreover, we show that downregulation of Cenpj in post-mitotic neurons increases stable microtubules and leads to slower neuronal migration, abnormal centrosome position and aberrant neuronal morphology. Moreover, rescue experiments shows that Cenpj mediates the role of Ascl1 in centrosome biogenesis in progenitor cells and in microtubule dynamics in migrating neurons. These data provide insights into genetic pathways controlling cortical development and primary microcephaly observed in humans with mutations in Cenpj. PMID:25753651

  12. Human Immunodeficiency Virus Type 1 gp120 Induces Apoptosis in Human Primary Neurons through Redox-Regulated Activation of Neutral Sphingomyelinase

    PubMed Central

    Jana, Arundhati; Pahan, Kalipada

    2007-01-01

    Human immunodeficiency virus type 1 (HIV-1) infection is known to cause disorders of the CNS, including HIV-associated dementia (HAD). HIV-1 coat protein gp120 (glycoprotein 120) induces neuronal apoptosis and has been implicated in the pathogenesis of HAD. However, the mechanism by which gp120 causes neuronal apoptosis is poorly understood. The present study underlines the importance of gp120 in inducing the production of ceramide, an important inducer of apoptosis, in human primary neurons. gp120 induced the activation of sphingomyelinases (primarily the neutral one) and the production of ceramide in primary neurons. Antisense knockdown of neutral (NSMase) but not acidic (ASMase) sphingomyelinase markedly inhibited gp120-mediated apoptosis and cell death of primary neurons, suggesting that the activation of NSMase but not ASMase plays an important role in gp120-mediated neuronal apoptosis. Similarly, the HIV-1 regulatory protein Tat also induced neuronal cell death via NSMase. Furthermore, gp120-induced production of ceramide was redox sensitive, because reactive oxygen species were involved in the activation of NSMase but not ASMase. gp120 coupled CXCR4 (CXC chemokine receptor 4) to induce NADPH oxidase-mediated production of superoxide radicals in neurons, which was involved in the activation of NSMase but not ASMase. These studies suggest that gp120 may induce neuronal apoptosis in the CNS of HAD patients through the CXCR4–NADPH oxidase–superoxide–NSMase–ceramide pathway. PMID:15509740

  13. In vivo clonal overexpression of neuroligin 3 and neuroligin 2 in neurons of the rat cerebral cortex. Differential effects on GABAergic synapses and neuronal migration

    PubMed Central

    Fekete, Christopher D.; Chiou, Tzu-Ting; Miralles, Celia P.; Harris, Rachel S.; Fiondella, Christopher G.; LoTurco, Joseph J.; De Blas, Angel L.

    2015-01-01

    We have studied the effect of clonal overexpression of neuroligin 3 (NL3) or neuroligin 2 (NL2) in the adult rat cerebral cortex following in utero electroporation (IUEP) at embryonic stage E14. Overexpression of NL3 leads to a large increase in vGAT and GAD65 in the GABAergic contacts that the overexpressing neurons receive. Overexpression of NL2 produced a similar effect but to a lesser extent. In contrast, overexpression of NL3 or NL2 after IUEP, does not affect vGlut1 in the glutamatergic contacts that the NL3 or NL2 overexpressing neurons receive. The NL3 or NL2 overexpressing neurons do not show increased innervation by parvalbumin-containing GABAergic terminals or increased parvalbumin in the same terminals that show increased vGAT. These results indicate that the observed increase in vGAT and GAD65 is not due to increased GABAergic innervation but to increased expression of vGAT and GAD65 in the GABAergic contacts that NL3 or NL2 overexpressing neurons receive. The majority of bright vGAT puncta contacting the NL3 overexpressing neurons have no gephyrin juxtaposed to them indicating that many of these contacts are non-synaptic. This contrasts with the majority of the NL2 overexpressing neurons, which show plenty of synaptic gephyrin clusters juxtaposed to vGAT. Besides having an effect on GABAergic contacts, overexpression of NL3 interferes with the neuronal radial migration, in the cerebral cortex, of the neurons overexpressing NL3. PMID:25565602

  14. Pressure-dependent effect of shock waves on rat brain: induction of neuronal apoptosis mediated by a caspase-dependent pathway.

    PubMed

    Kato, Kaoruko; Fujimura, Miki; Nakagawa, Atsuhiro; Saito, Atsushi; Ohki, Tomohiro; Takayama, Kazuyoshi; Tominaga, Teiji

    2007-04-01

    Shock waves have been experimentally applied to various neurosurgical treatments including fragmentation of cerebral emboli, perforation of cyst walls or tissue, and delivery of drugs into cells. Nevertheless, the application of shock waves to clinical neurosurgery remains challenging because the threshold for shock wave-induced brain injury has not been determined. The authors investigated the pressure-dependent effect of shock waves on histological changes of rat brain, focusing especially on apoptosis. Adult male rats were exposed to a single shot of shock waves (produced by silver azide explosion) at overpressures of 1 or 10 MPa after craniotomy. Histological changes were evaluated sequentially by H & E staining and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL). The expression of active caspase-3 and the effect of the nonselective caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (Z-VAD-FMK) were examined to evaluate the contribution of a caspase-dependent pathway to shock wave-induced brain injury. High-overpressure (> 10 MPa) shock wave exposure resulted in contusional hemorrhage associated with a significant increase in TUNEL-positive neurons exhibiting chromatin condensation, nuclear segmentation, and apoptotic bodies. The maximum increase was seen at 24 hours after shock wave application. Low-overpressure (1 MPa) shock wave exposure resulted in spindle-shaped changes in neurons and elongation of nuclei without marked neuronal injury. The administration of Z-VAD-FMK significantly reduced the number of TUNEL-positive cells observed 24 hours after high-overpressure shock wave exposure (p < 0.01). A significant increase in the cytosolic expression of active caspase-3 was evident 24 hours after high-overpressure shock wave application; this increase was prevented by Z-VAD-FMK administration. Double immunofluorescence staining showed that TUNEL-positive cells were exclusively neurons. The

  15. Neuroprotective effect of ebselen against intracerebroventricular streptozotocin-induced neuronal apoptosis and oxidative stress in rats.

    PubMed

    Unsal, Cuneyt; Oran, Mustafa; Albayrak, Yakup; Aktas, Cevat; Erboga, Mustafa; Topcu, Birol; Uygur, Ramazan; Tulubas, Feti; Yanartas, Omer; Ates, Ozkan; Ozen, Oguz Aslan

    2016-04-01

    The goal of this study was to examine the neuroprotective effect of ebselen against intracerebroventricular streptozotocin (ICV-STZ)-induced oxidative stress and neuronal apoptosis in rat brain. A total of 30 adult male Sprague-Dawley rats were randomly divided into 3 groups of 10 animals each: control, ICV-STZ, and ICV-STZ treated with ebselen. The ICV-STZ group rats were injected bilaterally with ICV-STZ (3 mg/kg) on days 1 and 3, and ebselen (10 mg/kg/day) was administered for 14 days starting from 1st day of ICV-STZ injection to day 14. Rats were killed at the end of the study and brain tissues were removed for biochemical and histopathological investigation. Our results demonstrated, for the first time, the neuroprotective effect of ebselen on Alzheimer's disease (AD) model in rats. Our present study, in ICV-STZ group, showed significant increase in tissue malondialdehyde levels and significant decrease in enzymatic antioxidants superoxide dismutase and glutathione peroxidase in the frontal cortex tissue. The histopathological studies in the brain of rats also supported that ebselen markedly reduced the ICV-STZ-induced histopathological changes and well preserved the normal histological architecture of the frontal cortex tissue. The number of apoptotic neurons was increased in frontal cortex tissue after ICV-STZ administration. Treatment of ebselen markedly reduced the number of degenerating apoptotic neurons. The study demonstrates the effectiveness of ebselen, as a powerful antioxidant, in preventing the oxidative damage and morphological changes caused by ICV-STZ in rats. Thus, ebselen may have a therapeutic value for the treatment of AD.

  16. Multipolar migration: the third mode of radial neuronal migration in the developing cerebral cortex.

    PubMed

    Tabata, Hidenori; Nakajima, Kazunori

    2003-11-05

    Two distinct modes of radial neuronal migration, locomotion and somal translocation, have been reported in the developing cerebral cortex. Although these two modes of migration have been well documented, the cortical intermediate zone contains abundant multipolar cells, and they do not resemble the cells migrating by locomotion or somal translocation. Here, we report that these multipolar cells express neuronal markers and extend multiple thin processes in various directions independently of the radial glial fibers. Time-lapse analysis of living slices revealed that the multipolar cells do not have any fixed cell polarity, and that they very dynamically extend and retract multiple processes as their cell bodies slowly move. They do not usually move straight toward the pial surface during their radial migration, but instead frequently change migration direction and rate; sometimes they even remain in almost the same position, especially when they are in the subventricular zone. Occasionally, the multipolar cells jump tangentially during their radial migration. Because the migration modality of these cells clearly differs from locomotion or somal translocation, we refer to their novel type of migration as "multipolar migration." In view of the high proportion of cells exhibiting multipolar migration, this third mode of radial migration must be an important type of migration in the developing cortex.

  17. Characterizing learning deficits and hippocampal neuron loss following transient global cerebral ischemia in rats.

    PubMed

    Hartman, Richard E; Lee, Jin M; Zipfel, Greg J; Wozniak, David F

    2005-05-10

    The 2-vessel-occlusion + hypotension (2VO + H) model of transient global cerebral ischemia results in neurodegeneration within the CA1 field of the hippocampus, but previous research has failed to demonstrate robust or reliable learning/memory deficits in rats subjected to this treatment. In the present study, sensitive behavioral protocols were developed in an effort to characterize the cognitive impairments following 2VO + H more precisely. Adult rats were exposed to 10 min of bilateral carotid occlusion with simultaneous hypotension. Following recovery, 2VO + H and control rats were subjected to a series of behavioral tests (locomotor activity, sensorimotor battery, water maze [cued, place, learning set], object recognition, and radial arm maze) over an extended recovery period followed by an assessment of neuronal loss in the dorsal hippocampus. The 2VO + H treatment was associated with long-lasting spatial learning deficits in the absence of other behavioral impairments and with neurodegeneration in dorsal hippocampal CA1. Water maze protocols that placed higher memory demands upon the rats (relatively "hard" vs. "easy") were more sensitive for detecting ischemia-induced deficits. We have shown that the use of appropriate behavioral tests (e.g., a relatively difficult place learning task) allowed for the observation of robust spatial learning deficits in a model previously shown to induce relatively subtle behavioral effects. Thus, the 2VO + H model induces both hippocampal neuronal loss and long-term learning deficits in rats, providing a potentially useful model for evaluating therapeutic efficacy.

  18. Neuronal activity (c-Fos) delineating interactions of the cerebral cortex and basal ganglia

    PubMed Central

    Qiu, Mei-Hong; Chen, Michael C.; Huang, Zhi-Li; Lu, Jun

    2014-01-01

    The cerebral cortex and basal ganglia (BG) form a neural circuit that is disrupted in disorders such as Parkinson’s disease. We found that neuronal activity (c-Fos) in the BG followed cortical activity, i.e., high in arousal state and low in sleep state. To determine if cortical activity is necessary for BG activity, we administered atropine to rats to induce a dissociative state resulting in slow-wave electroencephalography but hyperactive motor behaviors. Atropine blocked c-Fos expression in the cortex and BG, despite high c-Fos expression in the sub-cortical arousal neuronal groups and thalamus, indicating that cortical activity is required for BG activation. To identify which glutamate receptors in the BG that mediate cortical inputs, we injected ketamine [N-methyl-d-aspartate (NMDA) receptor antagonist] and 6-cyano-nitroquinoxaline-2, 3-dione (CNQX, a non-NMDA receptor antagonist). Systemic ketamine and CNQX administration revealed that NMDA receptors mediated subthalamic nucleus (STN) input to internal globus pallidus (GPi) and substantia nigra pars reticulata (SNr), while non-NMDA receptor mediated cortical input to the STN. Both types of glutamate receptors were involved in mediating cortical input to the striatum. Dorsal striatal (caudoputamen, CPu) dopamine depletion by 6-hydroxydopamine resulted in reduced activity of the CPu, globus pallidus externa (GPe), and STN but increased activity of the GPi, SNr, and putative layer V neurons in the motor cortex. Our results reveal that the cortical activity is necessary for BG activity and clarifies the pathways and properties of the BG-cortical network and their putative role in the pathophysiology of BG disorders. PMID:24723855

  19. Endogenous nitric oxide induces activation of apoptosis signal-regulating kinase 1 via S-nitrosylation in rat hippocampus during cerebral ischemia-reperfusion.

    PubMed

    Liu, D-H; Yuan, F-G; Hu, S-Q; Diao, F; Wu, Y-P; Zong, Y-Y; Song, T; Li, C; Zhang, G-Y

    2013-01-15

    Apoptosis signal-regulating kinase 1 (ASK1) is a general mediator of cell death in response to a variety of stimuli, including reactive oxygen species, tumor necrosis factor α, lipopolysaccharide, endoplasmic reticulum stress, calcium influx and ischemia. Here we reported ASK1 was activated by nitric oxide (NO) through S-nitrosylation during cerebral ischemia-reperfusion. The reagents that abrogate neuronal nitric oxide synthase (nNOS) activity such as nNOS inhibitor 7NI and N-methyl-D-aspartate receptor antagonist MK801 prevented ASK1 activation via decreasing ASK1 S-nitrosylation. In HEK293 cells, over-expressed ASK1 could be S-nitrosylated by both exogenous and endogenous NO and Cys869 was identified as the site of ASK1 S-nitrosylation. S-nitrosylation increased the level of ASK1 phosphorylation at Thr845, which represents ASK1 activation. Our results further confirmed that S-nitrosylation led to the increment of ASK1 dimerization. S-nitrosylation of ASK1 also activated the downstream JNK signaling and JNK-mediated nucleic pathway. The exogenous NO (SNP and GSNO) reversed the effect of endogenous NO by suppressing S-nitrosylation of ASK1 and exerted neuroprotection during ischemia-reperfusion. These results suggest that inhibiting ASK1 S-nitrosylation may be a novel approach for stroke therapy. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. Lithium chloride administration prevents spatial learning and memory impairment in repeated cerebral ischemia-reperfusion mice by depressing apoptosis and increasing BDNF expression in hippocampus.

    PubMed

    Fan, Mingyue; Jin, Wei; Zhao, Haifeng; Xiao, Yining; Jia, Yanqiu; Yin, Yu; Jiang, Xin; Xu, Jing; Meng, Nan; Lv, Peiyuan

    2015-09-15

    Lithium has been reported to have neuroprotective effects, but the preventive and treated role on cognition impairment and the underlying mechanisms have not been determined. In the present study, C57Bl/6 mice were subjected to repeated bilateral common carotid artery occlusion to induce the learning and memory deficits. 2 mmol/kg or 5 mmol/kg of lithium chloride (LiCl) was injected intraperitoneally per day before (for 7 days) or post (for 28 days) the operation. This repeated cerebral ischemia-reperfusion (IR) induced dynamic overexpression of ratio of Bcl-2/Bax and BDNF in hippocampus of mice. LiCl pretreatment and treatment significantly decreased the escape latency and increased the percentage of time that the mice spent in the target quadrant in Morris water maze. 2 mmol/kg LiCl evidently reversed the morphologic changes, up-regulated the survival neuron count and increased the BDNF gene and protein expression. 5 mmol/kg pre-LiCl significantly increased IR-stimulated reduce of Bcl-2/Bax and p-CREB/CREB. These results described suggest that pre-Li and Li treatment may induce a pronounced prevention on cognitive impairment. These effects may relay on the inhibition of apoptosis and increasing BDNF and p-CREB expression.

  1. Exposure to Cell Phone Radiation Up-Regulates Apoptosis Genes in Primary Cultures of Neurons and Astrocytes

    PubMed Central

    Zhao, Tian-Yong; Zou, Shi-Ping; Knapp, Pamela E.

    2007-01-01

    The health effects of cell phone radiation exposure are a growing public concern. This study investigated whether expression of genes related to cell death pathways are dysregulated in primary cultured neurons and astrocytes by exposure to a working GSM (Global System for Mobile Communication) cell phone rated at a frequency of 1900 MHz. Primary cultures were exposed to cell phone emissions for 2 hrs. We used array analysis and real-time RT-PCR to show up-regulation of caspase-2, caspase-6 and Asc (apoptosis associated speck-like protein containing a card) gene expression in neurons and astrocytes. Upregulation occurred in both “on” and “stand-by” modes in neurons, but only in “on” mode in astrocytes. Additionally, astrocytes showed up-regulation of the Bax gene. The effects are specific since up-regulation was not seen for other genes associated with apoptosis, such as caspase-9 in either neurons and astrocytes, or Bax in neurons. The results show that even relatively short-term exposure to cell phone radiofrequency emissions can up-regulate elements of apoptotic pathways in cells derived from the brain, and that neurons appear to be more sensitive to this effect than astrocytes. PMID:17187929

  2. Exposure to cell phone radiation up-regulates apoptosis genes in primary cultures of neurons and astrocytes.

    PubMed

    Zhao, Tian-Yong; Zou, Shi-Ping; Knapp, Pamela E

    2007-01-22

    The health effects of cell phone radiation exposure are a growing public concern. This study investigated whether expression of genes related to cell death pathways are dysregulated in primary cultured neurons and astrocytes by exposure to a working Global System for Mobile Communication (GSM) cell phone rated at a frequency of 1900MHz. Primary cultures were exposed to cell phone emissions for 2h. We used array analysis and real-time RT-PCR to show up-regulation of caspase-2, caspase-6 and Asc (apoptosis associated speck-like protein containing a card) gene expression in neurons and astrocytes. Up-regulation occurred in both "on" and "stand-by" modes in neurons, but only in "on" mode in astrocytes. Additionally, astrocytes showed up-regulation of the Bax gene. The effects are specific since up-regulation was not seen for other genes associated with apoptosis, such as caspase-9 in either neurons or astrocytes, or Bax in neurons. The results show that even relatively short-term exposure to cell phone radiofrequency emissions can up-regulate elements of apoptotic pathways in cells derived from the brain, and that neurons appear to be more sensitive to this effect than astrocytes.

  3. Impact of Ketamine on Learning and Memory Function, Neuronal Apoptosis and Its Potential Association with miR-214 and PTEN in Adolescent Rats

    PubMed Central

    Wang, Xiaobin; Yang, Xiaoling; Wang, Maohua; Zhang, Chunxiang; Zhou, Shuzhi; Tang, Ni

    2014-01-01

    Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, is used as a general pediatric anesthetic and anti-depressive drug. Recent studies suggest that ketamine enhances neuronal apoptosis in developing rats. The goal of this study is to explore whether ketamine could result in learning and memory impairment and neurodegeneration in adolescent rats, and if so, whether the effects of ketamine are associated with miR-214 and PTEN expression. Fifty-day-old SD rats were randomly divided into three groups receiving ketamine at 30, or 80 mg/kg, i.p. or saline for seven consecutive days. Twenty-four hours after the last treatment, learning and memory function were tested by the Morris water maze. The rats were then decapitated, and the brains were isolated for detection of neuronal apoptosis and protein PTEN expression by TUNEL and immunohistochemistry respectively. Expression levels of the miR-214 and PTEN in the hippocampus were measured by qRT-PCR and western blot analysis respectively. Ketamine administered to the adolescent rats at a dose of 80 mg/kg rather than the lower dose of 30 mg/kg caused learning and memory impairment, increased the number of apoptotic cells in the hippocampal CA1 region, cerebral cortex and subcortical region, decreased the miR-214 levels and increased PTEN protein expression in hippocampus. The results suggest that ketamine at a dose of 80 mg/kg in the adolescent rats is able to induce the learning and memory impairment and neurodegeneration, in which the down-regulation of miR-214 and high expression of PTEN protein may be involved. PMID:24914689

  4. [The study on the relationship between hippocampus neuronal apoptosis and hippocampus synaptic plasticity in rats exposed to aluminum].

    PubMed

    Nie, Xiaohan; Qin, Xiujun; Zhang, Huifang; Kang, Pan; Li, Zhaoyang; Niu, Qiao

    2015-07-01

    To investigate the effect of aluminum exposure on neuronal apoptosis of rats hippocampus and the correlation of and synaptic plasticity. There were 40 SPF grade SD rats which were randomly divided into four groups: the control group, the low dose group, the medium dose group and the high dose group, 10 rats in each group. The rats were daily gavaged with aluminum lactate for 30 days. The hippocampal fEPSPs in rat was measured by electrophysiological grapher and the neuronal apoptosis in hippocampus was detected by Flow cytometer. In addition, the relative expression of gene which includes caspase-3, 8, 9 was measured by Real-time PCR. Compared to the control group, the average of fEPSPs which after HFS 10, 20, 30, 40, 50, 60 min was decreased at different time point in the low dose group, the medium dose group and the high dose group (P < 0.05). Compared with the control group, the rate of apoptosis was significantly increased in the medium dose group and the high dose group (P < 0.05). Compared to the control group, the relative expression of caspase-3 in the medium dose group and the high dose group was significantly increased in Real-time PCR (P < 0.05), and the relative expression of caspase-8 in the high dose group was significantly increased (P < 0.05). Aluminum exposure may induced neuronal apoptosis in rats, and then affect hippocampal synaptic plasticity.

  5. Transcriptional landscapes at the intersection of neuronal apoptosis and substance P-induced survival: exploring pathways and drug targets

    PubMed Central

    Paparone, S; Severini, C; Ciotti, M T; D’Agata, V; Calissano, P; Cavallaro, S

    2016-01-01

    A change in the delicate equilibrium between apoptosis and survival regulates the neurons fate during the development of nervous system and its homeostasis in adulthood. Signaling pathways promoting or protecting from apoptosis are activated by multiple signals, including those elicited by neurotrophic factors, and depend upon specific transcriptional programs. To decipher the rescue program induced by substance P (SP) in cerebellar granule neurons, we analyzed their whole-genome expression profiles after induction of apoptosis and treatment with SP. Transcriptional pathways associated with the survival effect of SP included genes encoding for proteins that may act as pharmacological targets. Inhibition of one of these, the Myc pro-oncogene by treatment with 10058-F4, reverted in a dose-dependent manner the rescue effect of SP. In addition to elucidate the transcriptional mechanisms at the intersection of neuronal apoptosis and survival, our systems biology-based perspective paves the way towards an innovative pharmacology based on targets downstream of neurotrophic factor receptors. PMID:27551538

  6. The neuron-astrocyte-microglia triad in a rat model of chronic cerebral hypoperfusion: protective effect of dipyridamole

    PubMed Central

    Lana, Daniele; Melani, Alessia; Pugliese, Anna Maria; Cipriani, Sara; Nosi, Daniele; Pedata, Felicita; Giovannini, Maria Grazia

    2014-01-01

    Chronic cerebral hypoperfusion during aging may cause progressive neurodegeneration as ischemic conditions persist. Proper functioning of the interplay between neurons and glia is fundamental for the functional organization of the brain. The aim of our research was to study the pathophysiological mechanisms, and particularly the derangement of the interplay between neurons and astrocytes-microglia with the formation of “triads,” in a model of chronic cerebral hypoperfusion induced by the two-vessel occlusion (2VO) in adult Wistar rats (n = 15). The protective effect of dipyridamole given during the early phases after 2VO (4 mg/kg/day i.v., the first 7 days after 2VO) was verified (n = 15). Sham-operated rats (n = 15) were used as controls. Immunofluorescent triple staining of neurons (NeuN), astrocytes (GFAP), and microglia (IBA1) was performed 90 days after 2VO. We found significantly higher amount of “ectopic” neurons, neuronal debris and apoptotic neurons in CA1 Str. Radiatum and Str. Pyramidale of 2VO rats. In CA1 Str. Radiatum of 2VO rats the amount of astrocytes (cells/mm2) did not increase. In some instances several astrocytes surrounded ectopic neurons and formed a “micro scar” around them. Astrocyte branches could infiltrate the cell body of ectopic neurons, and, together with activated microglia cells formed the “triads.” In the triad, significantly more numerous in CA1 Str. Radiatum of 2VO than in sham rats, astrocytes and microglia cooperated in the phagocytosis of ectopic neurons. These events might be common mechanisms underlying many neurodegenerative processes. The frequency to which they appear might depend upon, or might be the cause of, the burden and severity of neurodegeneration. Dypiridamole significantly reverted all the above described events. The protective effect of chronic administration of dipyridamole might be a consequence of its vasodilatory, antioxidant and anti-inflammatory role during the early phases after 2VO

  7. A fibronectin-like molecule is present in the developing cat cerebral cortex and is correlated with subplate neurons

    PubMed Central

    1988-01-01

    The subplate is a transient zone of the developing cerebral cortex through which postmitotic neurons migrate and growing axons elongate en route to their adult positions within the cortical plate. To learn more about the cellular interactions that occur in this zone, we have examined whether fibronectins (FNs), a family of molecules known to promote migration and elongation in other systems, are present during the fetal and postnatal development of the cat's cerebral cortex. Three different anti-FN antisera recognized a single broad band with an apparent molecular mass of 200-250 kD in antigen-transfer analyses (reducing conditions) of plasma-depleted (perfused) whole fetal brain or synaptosome preparations, indicating that FNs are present at these ages. This band can be detected as early as 1 mo before birth at embryonic day 39. Immunohistochemical examination of the developing cerebral cortex from animals between embryonic day 46 and postnatal day 7 using any of the three antisera revealed that FN-like immunoreactivity is restricted to the subplate and the marginal zones, and is not found in the cortical plate. As these zones mature into their adult counterparts (the white matter and layer 1 of the cerebral cortex), immunostaining gradually disappears and is not detectable by postnatal day 70. Previous studies have shown that the subplate and marginal zones contain a special, transient population of neurons (Chun, J. J. M., M. J. Nakamura, and C. J. Shatz. 1987. Nature (Lond.). 325:617-620). The FN-like immunostaining in the subplate and marginal zone is closely associated with these neurons, and some of the immunostaining delineates them. Moreover, the postnatal disappearance of FN-like immunostaining from the subplate is correlated spatially and temporally with the disappearance of the subplate neurons. When subplate neurons are killed by neurotoxins, FN-like immunostaining is depleted in the lesioned area. These observations show that an FN-like molecule is

  8. Azilsartan ameliorates apoptosis of dopaminergic neurons and rescues characteristic parkinsonian behaviors in a rat model of Parkinson’s disease

    PubMed Central

    Gao, Qing; Ou, Zhou; Jiang, Teng; Tian, You-Yong; Zhou, Jun-Shan; Wu, Liang; Shi, Jian-Quan; Zhang, Ying-Dong

    2017-01-01

    Loss of dopaminergic neurons within the substantia nigra (SN) is a pathological hallmark of Parkinsons disease (PD), which leads to the onset of motor symptoms. Previously, our in vitro studies revealed that Angiotensin II (Ang II) induced apoptosis of dopaminergic neurons through its type 1 receptor (AT1R), but these findings needed to be confirmed via animal experiments. Here, using a rotenone-induced rat model of PD, we observed an overactivation of Ang II/AT1R axis in the SN, since Ang II level and AT1R expression were markedly increased. Furthermore, we provided in vivo evidence that Ang II directly elicited apoptosis of dopaminergic neurons via activation of AT1R in the SN of rats. More importantly, we showed for the first time that oral administration of azilsartan, a newly developed AT1R blocker approved by the U.S. Food and Drug Administration for hypertension treatment, rescued the apoptosis of dopaminergic neurons and relieved the characteristic parkinsonian symptoms in PD rats. These results support the application of AT1R blockers in PD therapy, and strengthen the notion that many therapeutic agents may possess pleiotropic action in addition to their main applications. PMID:28445961

  9. Azilsartan ameliorates apoptosis of dopaminergic neurons and rescues characteristic parkinsonian behaviors in a rat model of Parkinson's disease.

    PubMed

    Gao, Qing; Ou, Zhou; Jiang, Teng; Tian, You-Yong; Zhou, Jun-Shan; Wu, Liang; Shi, Jian-Quan; Zhang, Ying-Dong

    2017-04-11

    Loss of dopaminergic neurons within the substantia nigra (SN) is a pathological hallmark of Parkinson's disease (PD), which leads to the onset of motor symptoms. Previously, our in vitro studies revealed that Angiotensin II (Ang II) induced apoptosis of dopaminergic neurons through its type 1 receptor (AT1R), but these findings needed to be confirmed via animal experiments. Here, using a rotenone-induced rat model of PD, we observed an overactivation of Ang II/AT1R axis in the SN, since Ang II level and AT1R expression were markedly increased. Furthermore, we provided in vivo evidence that Ang II directly elicited apoptosis of dopaminergic neurons via activation of AT1R in the SN of rats. More importantly, we showed for the first time that oral administration of azilsartan, a newly developed AT1R blocker approved by the U.S. Food and Drug Administration for hypertension treatment, rescued the apoptosis of dopaminergic neurons and relieved the characteristic parkinsonian symptoms in PD rats. These results support the application of AT1R blockers in PD therapy, and strengthen the notion that many therapeutic agents may possess pleiotropic action in addition to their main applications.

  10. Aβ-Induced Drp1 phosphorylation through Akt activation promotes excessive mitochondrial fission leading to neuronal apoptosis.

    PubMed

    Kim, Dah Ihm; Lee, Ki Hoon; Gabr, Amr Ahmed; Choi, Gee Euhn; Kim, Jun Sung; Ko, So Hee; Han, Ho Jae

    2016-11-01

    Mitochondrial dysfunction is known as one of causative factors in Alzheimer's disease (AD), inducing neuronal cell death. Mitochondria regulate their functions through changing their morphology. The present work was undertaken to investigate whether Amyloid β (Aβ) affects mitochondrial morphology in neuronal cells to induce apoptosis. Aβ treatment induced not only the fragmentation of mitochondria but also neuronal apoptosis in association with an increase in caspase-9 and -3 activity. Calcium influx induced by Aβ up-regulated the activation of Akt through CaMKII resulting in changes to the phosphorylation level of Drp1 in a time-dependent manner. Translocation of Drp1 from the cytosol to mitochondria was blocked by CB-124005 (an Akt inhibitor). Recruitment of Drp1 to mitochondria led to ROS generation and mitochondrial fission, accompanied by dysfunction of mitochondria such as loss of membrane potential and ATP production. ROS generation and mitochondrial dysfunction by Aβ were attenuated when treated with Mdivi-1, a selective Drp1 inhibitor. Furthermore, the sustained Akt activation induced not only the fragmentation of mitochondria but also the activation of mTOR, eventually suppressing autophagy. Inhibition of autophagic clearance of Aβ led to increased ROS levels and aggravating mitochondrial defects, which were blocked by Rapamycin (an mTOR inhibitor). In conclusion, sustained phosphorylation of Akt by Aβ directly activates Drp1 and inhibits autophagy through the mTOR pathway. Together, these changes elicit abundant mitochondrial fragmentation resulting in ROS-mediated neuronal apoptosis.

  11. Recombinant human brain-derived neurotrophic factor prevents neuronal apoptosis in a novel in vitro model of subarachnoid hemorrhage.

    PubMed

    Li, Mingchang; Wang, Yuefei; Wang, Wei; Zou, Changlin; Wang, Xin; Chen, Qianxue

    2017-01-01

    Subarachnoid hemorrhage (SAH) is a hemorrhagic stroke with high mortality and morbidity. An animal model for SAH was established by directly injecting a hemolysate into the subarachnoid space of rats or mice. However, the in vitro applications of the hemolysate SAH model have not been reported, and the mechanisms remain unclear. In this study, we established an in vitro SAH model by treating cortical pyramidal neurons with hemolysate. Using this model, we assessed the effects of recombinant human brain-derived neurotrophic factor (rhBDNF) on hemolysate-induced cell death and related mechanisms. Cortical neurons were treated with 10 ng/mL or 100 ng/mL rhBDNF prior to application of hemolysate. Hemolysate treatment markedly increased cell loss, triggered apoptosis, and promoted the expression of caspase-8, caspase-9, and cleaved caspase-3. rhBDNF significantly inhibited hemolysate-induced cell loss, neuronal apoptosis, and expression of caspase-8, caspase-9, and cleaved caspase-3. Our data revealed a previously unrecognized protective activity of rhBDNF against hemolysate-induced cell death, potentially via regulation of caspase-9-, caspase-8-, and cleaved caspase-3-related apoptosis. This study implicates that hemolysate-induced cortical neuron death represents an important in vitro model of SAH.

  12. α-Lipoic acid inhibits sevoflurane-induced neuronal apoptosis through PI3K/Akt signalling pathway.

    PubMed

    Ma, Rong; Wang, Xiang; Peng, Peipei; Xiong, Jingwei; Dong, Hongquan; Wang, Lixia; Ding, Zhengnian

    2016-01-01

    Sevoflurane is a widely used anaesthetic agent, including in anaesthesia of children and infants. Recent studies indicated that the general anaesthesia might cause the cell apoptosis in the brain. This issue raises the concerns about the neuronal toxicity induced by the application of anaesthetic agents, especially in the infants and young children. In this study, we used Morris water maze, western blotting and immunohistochemistry to elucidate the role of α-lipoic acid in the inhibition of neuronal apoptosis. We found that sevoflurane led to the long-term cognitive impairment in the young rats. This adverse effect may be caused by the neuronal death in the hippocampal region, mediated through PI3K/Akt signalling pathway. We also showed that α-lipoic acid offset the effect of sevoflurane on the neuronal apoptosis and cognitive dysfunction. This study elucidated the potential clinical role of α-lipoic acid, providing a promising way in the prevention and treatment of long-term cognitive impairment induced by sevoflurane general anesthesia.

  13. Lychee Seed Saponins Improve Cognitive Function and Prevent Neuronal Injury via Inhibiting Neuronal Apoptosis in a Rat Model of Alzheimer’s Disease

    PubMed Central

    Wang, Xiuling; Wu, Jianming; Yu, Chonglin; Tang, Yong; Liu, Jian; Chen, Haixia; Jin, Bingjin; Mei, Qibing; Cao, Shousong; Qin, Dalian

    2017-01-01

    Lychee seed is a traditional Chinese medicine and possesses many activities, including hypoglycemia, liver protection, antioxidation, antivirus, and antitumor. However, its effect on neuroprotection is still unclear. The present study investigated the effects of lychee seed saponins (LSS) on neuroprotection and associated mechanisms. We established a rat model of Alzheimer’s disease (AD) by injecting Aβ25–35 into the lateral ventricle of rats and evaluated the effect of LSS on spatial learning and memory ability via the Morris water maze. Neuronal apoptosis was analyzed by hematoxylin and eosin stain and terminal deoxynucleotidyl transferase (Tdt)-mediated dUTP nick-end labeling analysis, and mRNA expression of caspase-3 and protein expressions of Bax and Bcl-2 by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, respectively. The results showed that LSS remarkably improved cognitive function and alleviated neuronal injury by inhibiting apoptosis in the hippocampus of AD rats. Furthermore, the mRNA expression of caspase-3 and the protein expression of Bax were downregulated, while the protein expression of Bcl-2 and the ratio of Bcl-2/Bax were increased by LSS. We demonstrate that LSS significantly improves cognitive function and prevent neuronal injury in the AD rats via regulation of the apoptosis pathway. Therefore, LSS may be developed as a nutritional supplement and sold as a drug for AD prevention and/or treatment. PMID:28165366

  14. 14,15-EET promotes mitochondrial biogenesis and protects cortical neurons against oxygen/glucose deprivation-induced apoptosis.

    PubMed

    Wang, Lai; Chen, Man; Yuan, Lin; Xiang, Yuting; Zheng, Ruimao; Zhu, Shigong

    2014-07-18

    14,15-Epoxyeicosatrienoic acid (14,15-EET), a metabolite of arachidonic acid, is enriched in the brain cortex and exerts protective effect against neuronal apoptosis induced by ischemia/reperfusion. Although apoptosis has been well recognized to be closely associated with mitochondrial biogenesis and function, it is still unclear whether the neuroprotective effect of 14,15-EET is mediated by promotion of mitochondrial biogenesis and function in cortical neurons under the condition of oxygen-glucose deprivation (OGD). In this study, we found that 14,15-EET improved cell viability and inhibited apoptosis of cortical neurons. 14,15-EET significantly increased the mitochondrial mass and the ratio of mitochondrial DNA to nuclear DNA. Key makers of mitochondrial biogenesis, peroxisome proliferator activator receptor gamma-coactivator 1 alpha (PGC-1α), nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM), were elevated at both mRNA and protein levels in the cortical neurons treated with 14,15-EET. Moreover, 14,15-EET markedly attenuated the decline of mitochondrial membrane potential, reduced ROS, while increased ATP synthesis. Knockdown of cAMP-response element binding protein (CREB) by siRNA blunted the up-regulation of PGC-1α and NRF-1 stimulated by 14,15-EET, and consequently abolished the neuroprotective effect of 14,15-EET. Our results indicate that 14,15-EET protects neurons from OGD-induced apoptosis by promoting mitochondrial biogenesis and function through CREB mediated activation of PGC-1α and NRF-1.

  15. JIP3 regulates neuronal radial migration by mediating TrkB axonal anterograde transport in the developing cerebral cortex.

    PubMed

    Ma, Huixian; Yu, Hui; Li, Ting; Zhao, Yan; Hou, Ming; Chen, Zheyu; Wang, Yue; Sun, Tao

    2017-04-15

    Radial migration is essential for the precise lamination and the coordinated function of the cerebral cortex. However, the molecular mechanisms for neuronal radial migration are not clear. Here, we report that c-Jun NH2-terminal kinase (JNK)-interacting protein-3 (JIP3) is highly expressed in the brain of embryonic mice and essential for radial migration. Knocking down JIP3 by in utero electroporation specifically perturbs the radial migration of cortical neurons but has no effect on neurogenesis and neuronal differentiation. Furthermore, we illustrate that JIP3 knockdown delays but does not block the migration of cortical neurons by investigating the distribution of neurons with JIP3 knocked down in the embryo and postnatal mouse. Finally, we find that JIP3 regulates cortical neuronal migration by mediating TrkB axonal anterograde transport during brain development. These findings deepen our understanding of the regulation of neuronal development by JIP3 and provide us a novel view on the regulating mechanisms of neuronal radial migration. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Celastrol ameliorates Cd-induced neuronal apoptosis by targeting NOX2-derived ROS-dependent PP5-JNK signaling pathway.

    PubMed

    Xu, Chong; Wang, Xiaoxue; Gu, Chenjian; Zhang, Hai; Zhang, Ruijie; Dong, Xiaoqing; Liu, Chunxiao; Hu, Xiaoyu; Ji, Xiang; Huang, Shile; Chen, Long

    2017-04-01

    Celastrol, a plant-derived triterpene, has neuroprotective benefit in the models of neurodegenerative disorders that are characterized by overproduction of reactive oxygen species (ROS). Recently, we have reported that cadmium (Cd) activates c-Jun N-terminal kinase (JNK) pathway leading to neuronal cell death by inducing ROS inactivation of protein phosphatase 5 (PP5), and celastrol prevents Cd-activated JNK pathway against neuronal apoptosis. Therefore, we hypothesized that celastrol could hinder Cd induction of ROS-dependent PP5-JNK signaling pathway from apoptosis in neuronal cells. Here, we show that celastrol attenuated Cd-induced expression of NADPH oxidase 2 (NOX2) and its regulatory proteins (p22(phox) , p40(phox) , p47(phox) , p67(phox) , and Rac1), as well as the generation of ROS in PC12 cells and primary neurons. Also, N-acetyl-l-cysteine, a ROS scavenger, potentiated celastrol's inhibition of the events in the cells triggered by Cd, implying neuroprotection by celastrol via blocking Cd-evoked NOX2-derived ROS. Further research revealed that celastrol was involved in the regulation of PP5 inactivation and JNK/c-Jun activation induced by Cd, as celastrol prevented Cd from reducing PP5 expression, and over-expression of wild-type PP5 or dominant negative c-Jun strengthened celastrol's inhibition of Cd-induced phosphorylation of JNK and/or c-Jun, as well as apoptosis in neuronal cells. Of importance, inhibiting NOX2 with apocynin or silencing NOX2 by RNA interference enhanced the inhibitory effects of celastrol on Cd-induced inactivation of PP5, activation of JNK/c-Jun, ROS, and apoptosis in the cells. Furthermore, we noticed that expression of wild-type PP5 or dominant negative c-Jun, or pretreatment with JNK inhibitor SP600125 reinforced celastrol's suppression of Cd-induced NOX2 and its regulatory proteins, and consequential ROS in neuronal cells. These findings indicate that celastrol ameliorates Cd-induced neuronal apoptosis via targeting NOX2-derived

  17. Isoquercetin ameliorates tunicamycin-induced apoptosis in rat dorsal root ganglion neurons via suppressing ROS-dependent endoplasmic reticulum stress.

    PubMed

    Lu, Tan; Zhang, Chao; Chai, Mingxiang; An, Yongbo

    2016-05-01

    Recent studies showed that Isoquercetin (Iso), a novel extracts of plants and fruits could protect neuronal cells from neurotoxicity and neuro-inflammation. However, its role in acute spinal cord injury (ASCI) have not been elucidated. In the present study, we investigated whether Iso could prevent Tunicamycin (TUN)-induced rat dorsal root ganglion (DRG) neurons from apoptosis and endoplasmic reticulum (ER) stress. DRG neurons were pre-treated with different doses of Iso for 24h (h) and then were stimulated with TUN (0.75μg/ml) for 24h. The cytotoxic effects and apoptosis were detected by MTT assay and TUNEL staining. The protein and mRNA expression levels were detected by Real Time PCR and Western blot, respectively. The localization of cleaved caspase-12 was evaluated by immunofluorescent staining and Western blot. The activation of caspase were measured by colorimetric assays and Western blot. Lactate Dehydrogenase (LDH) and Malondialdehyde (MDA) leakage were detected by the LDH or MDA Detection Kit PLUS. Iso protected TUN-associated DRG neurons from being damaged by cytotoxicity and apoptosis in a dose-dependent manner. Increased LDH and MDA leakage and proportion of TUNEL-positive cells, activation of caspase-3 and -9, increased Bcl-2 Assaciated X protein (Bax)/B cell lymphoma/lewkmia-2 (Bcl-2) ratio and mRNA levels of p53 Upregulated Modulator Of Apoptosis (PUMA) and DP5, and mitochondrial Cytochrome c release. Additionally, Iso down-regulated mRNA levels of ER stress genes, such as glucose-regulated protein 78 (GRP78), GRP94, C/EBP homologous protein (CHOP), and cleaved caspase-12 in TUN-induced DRG neurons. Moreover, Iso blocked the activation of three key branches of unfolded protein response in DRG neurons, including phosphorylation of pancreatic ER stress kinase (PERK), eukaryotic initiation factor 2 alpha (eIF2α), inositol-requiring enzyme 1α (IRE1α), and transcription factor 6 (ATF6). Collectively, Iso prevented TUN-induced DRG neurons apoptosis by

  18. [Mechanism for apoptosis of hippocampus neuron induced by hypothyroidism in perinatal rats].

    PubMed

    Huang, Xin-wen; Yang, Ru-lai; Zhao, Zheng-yan; Ji, Chai; Yang, Rong-wang

    2005-07-01

    To investigate the mechanism for the apoptosis of hippocampus neuron induced by hypothyroidism in perinatal rats. Hypothyroidism was induced by administration of propylthiouracil (PTU, 50 mg/d) solution to the dams from gestational day 15 by gavage. Pups from both hypothyroid and control groups were harvested at 1, 5, 10 and 15d, respectively. Blood samples were collected at the time of death for the determination of thyroid hormone. Serum free triiodothyronine (FT(3)) and free thyroxine (FT(4)) were measured by chemoluminescence. Hippocampus specimens were collected from the control and hypothyroid pups.Mitochondia was examined under transmission electron microscopy. Translocation of apoptogenic molecules (Bax, cytochrome C and AIF) and activation of caspase-3 were analyzed by Western Blotting. Significantly low circulating FT(3) and FT(4) levels confirmed the hypothyroid status of the experimental pups. Electron microscopy showed that altered morphology of mitochondria significantly increased under hypothyroid conditions. The expression of Bax in the cytosol of hypothyroid pups was higher than that of control pups at all stages of development (P<0.05),and significantly higher in mitochondria (P<0.001). The expression of cytochrome c in the cytosol of hypothyroid pups was significantly higher than that of control pups at all stages of development (1,10 and 15 d:P<0.05, 5d: P<0.001), and lower in mitochondria (P<0.05). The expression of AIF in the cytosol of hypothyroid pups was higher than that of control pups at all stages of development (P<0.001), and significantly lower in mitochondria (1, 5d: P<0.001, 10, 15 d: P<0.01). he expression of caspase-3 P20 in the cytosol of hypothyroid pups was significantly higher as compared with that of the age-matched controls (1, 15d: P<0.01, 5,1 0 d: P<0.001). The intrinsic death pathway in mitochondria may be one of the mechanisms with which hypothyroid induces apoptosis of hippocampus neuron in developing rats.

  19. Simultaneous electroencephalography, real-time measurement of lactate concentration and optogenetic manipulation of neuronal activity in the rodent cerebral cortex.

    PubMed

    Clegern, William C; Moore, Michele E; Schmidt, Michelle A; Wisor, Jonathan

    2012-12-19

    Although the brain represents less than 5% of the body by mass, it utilizes approximately one quarter of the glucose used by the body at rest(1). The function of non rapid eye movement sleep (NREMS), the largest portion of sleep by time, is uncertain. However, one salient feature of NREMS is a significant reduction in the rate of cerebral glucose utilization relative to wakefulness(2-4). This and other findings have led to the widely held belief that sleep serves a function related to cerebral metabolism. Yet, the mechanisms underlying the reduction in cerebral glucose metabolism during NREMS remain to be elucidated. One phenomenon associated with NREMS that might impact cerebral metabolic rate is the occurrence of slow waves, oscillations at frequencies less than 4 Hz, in the electroencephalogram(5,6). These slow waves detected at the level of the skull or cerebral cortical surface reflect the oscillations of underlying neurons between a depolarized/up state and a hyperpolarized/down state(7). During the down state, cells do not undergo action potentials for intervals of up to several hundred milliseconds. Restoration of ionic concentration gradients subsequent to action potentials represents a significant metabolic load on the cell(8); absence of action potentials during down states associated with NREMS may contribute to reduced metabolism relative to wake. Two technical challenges had to be addressed in order for this hypothetical relationship to be tested. First, it was necessary to measure cerebral glycolytic metabolism with a temporal resolution reflective of the dynamics of the cerebral EEG (that is, over seconds rather than minutes). To do so, we measured the concentration of lactate, the product of aerobic glycolysis, and therefore a readout of the rate of glucose metabolism in the brains of mice. Lactate was measured using a lactate oxidase based real time sensor embedded in the frontal cortex. The sensing mechanism consists of a platinum

  20. Consistent injury to medium spiny neurons and white matter in the mouse striatum after prolonged transient global cerebral ischemia.

    PubMed

    Yoshioka, Hideyuki; Niizuma, Kuniyasu; Katsu, Masataka; Sakata, Hiroyuki; Okami, Nobuya; Chan, Pak H

    2011-04-01

    A reproducible transient global cerebral ischemia (tGCI) mouse model has not been fully established. Although striatal neurons and white matter are recognized to be vulnerable to ischemia, their injury after tGCI in mice has not been elucidated. The purpose of this study was to evaluate injuries to striatal neurons and white matter after tGCI in C57BL/6 mice, and to develop a reproducible tGCI model. Male C57BL/6 mice were subjected to tGCI by bilateral common carotid artery occlusion (BCCAO). Mice whose cortical cerebral blood flow after BCCAO decreased to less than 13% of the pre-ischemic value were used. Histological analysis showed that at 3 days after 22 min of BCCAO, striatal neurons were injured more consistently than those in other brain regions. Quantitative analysis of cytochrome c release into the cytosol and DNA fragmentation in the striatum showed consistent injury to the striatum. Immunohistochemistry and Western blot analysis revealed that DARPP-32-positive medium spiny neurons, the majority of striatal neurons, were the most vulnerable among the striatal neuronal subpopulations. The striatum (especially medium spiny neurons) was susceptible to oxidative stress after tGCI, which is probably one of the mechanisms of vulnerability. SMI-32 immunostaining showed that white matter in the striatum was also consistently injured 3 days after 22 min of BCCAO. We thus suggest that this is a tGCI model using C57BL/6 mice that consistently produces neuronal and white matter injury in the striatum by a simple technique. This model can be highly applicable for elucidating molecular mechanisms in the brain after global ischemia.

  1. Sex differences in brain proteomes of neuron-specific STAT3-null mice after cerebral ischemia/reperfusion.

    PubMed

    Di Domenico, Fabio; Casalena, Gabriella; Jia, Jia; Sultana, Rukhsana; Barone, Eugenio; Cai, Jian; Pierce, William M; Cini, Chiara; Mancuso, Cesare; Perluigi, Marzia; Davis, Catherine M; Alkayed, Nabil J; Butterfield, D Allan; Butterfield, Allan D

    2012-05-01

    Signal transduction and activator of transcription-3 (STAT3) plays an important role in neuronal survival, regeneration and repair after brain injury. We previously demonstrated that STAT3 is activated in brain after cerebral ischemia specifically in neurons. The effect was sex-specific and modulated by sex steroids, with higher activation in females than males. In the current study, we used a proteomics approach to identify downstream proteins affected by ischemia in male and female wild-type (WT) and neuron-specific STAT3 knockout (KO) mice. We established four comparison groups based on the transgenic condition and the hemisphere analyzed, respectively. Moreover, the sexual variable was taken into account and male and female animals were analyzed independently. Results support a role for STAT3 in metabolic, synaptic, structural and transcriptional responses to cerebral ischemia, indeed the adaptive response to ischemia/reperfusion injury is delayed in neuronal-specific STAT3 KO mice. The differences observed between males and females emphasize the importance of sex-specific neuronal survival and repair mechanisms, especially those involving antioxidant and energy-related activities, often caused by sex hormones.

  2. [Pharmacological correction of neuronal damage in sensomotor zone of frontal cortex under conditions of experimental cerebral blood flow pathology].

    PubMed

    Gorbacheva, S V; Belenichev, I F; Dunaev, V V; Bukhtiiarova, N V

    2007-01-01

    The administration of thiotriazoline, emoxypine and magnelong (a combined glycine-magnesium preparation) to animals with acute cerebral circulatory insufficiency showed significant neuroprotective effect in both acute and late ischemic periods, as indicated by the indices of cell density and number and the characteristics of apoptic and destructed neurons approaching those in the group of intact rats. Pyracetam showed cerebroprotective effect only in late ischemic period. Magnelong exhibited the most significant neuroprotective effect, maintaining cell density on the intact control level and reducing the number of apoptotic and destructed neurons.

  3. Mutant presenilin2 promotes apoptosis through the p53/miR-34a axis in neuronal cells.

    PubMed

    Li, Liu-Hong; Tu, Qiu-Yun; Deng, Xiao-Hua; Xia, Jian; Hou, De-Ren; Guo, Ke; Zi, Xiao-Hong

    2017-05-01

    Neurodegenerative disorders have attracted attention in last decades due to their high incidence in the world. The p53/miR-34a axis triggers apoptosis and suppresses viability in multiple types of cells, but little is known about its role in neurodegenerative diseases. In this study, we showed that presenilin (PS)-2, a major gene associated with familial Alzheimer's disease (AD) could trigger the apoptosis through the p53/miR-34a axis in PC12 cells. First we found that PC12 cell viability was downregulated by PS-2 and mutant PS-2 overexpression, especially by mutant PS-2 overexpression. Then, we established a mutant PS-2-overexpressing PC12 cell line and confirmed that mutant PS-2 induced not only p53 but also miR-34a expression. The transfection of miR-34a inhibitor reversed PS-2-induced effects on cellular viability and apoptosis. Mutant PS-2 overexpression promoted caspase-3 expression, reduced Sirt1 and Bcl-2 expression, all of which were miR-34a downstream genes related with cell apoptosis. Moreover, mutant PS-2 also activated the p53/miR-34a axis and induced apoptosis in AD transgenic mice brain. These results implied that mutant PS-2 might promote the apoptosis of neuronal cells through triggering the p53/miR-34a axis. Altogether our results provide a novel insight into neurodegenerative disease and deepen our understandings of AD pathogenic processes.

  4. Regulation of cerebral blood flow in the hippocampus by neuronal activation through the perforant path: relationship between hippocampal blood flow and neuronal plasticity.

    PubMed

    Hamadate, Naobumi; Yamaguchi, Taku; Sugawara, Aya; Tsujimatsu, Aki; Izumi, Takeshi; Yoshida, Takayuki; Ohmura, Yu; Yoshioka, Mitsuhiro

    2011-09-30

    Although changes in regional cerebral blood flow (rCBF) have been used as an index of neuronal activity, the effects of long-term potentiation (LTP) in the hippocampus, widely assumed to be an electrophysiological basis of learning and memory, on the changes in rCBF by neuronal activity remain unclear. Hence, to elucidate whether the effects of LTP in the hippocampus reflect in the correlation between neuronal activity and co-occurring changes in rCBF, we investigated the effects of LTP on the responses of hippocampal blood flow (HBF) to the electrical stimulation of the perforant path in vivo. We continuously measured HBF using Laser-Doppler flowmetry, and systemic blood pressure and heart rate were measured from the femoral artery during electrical stimulations in halothane-anesthetized rats. The results showed that the reactivity of HBF to neuronal activation was potentiated by a tetanic stimulation that induces LTP, although the tetanic stimulation did not affect baseline of HBF values. These results suggest that the presence of the plasticity between neuronal activity and the rCBF in the perforant path-dentate pathway, and the neuronal plasticity can be reflected in the transient changes in rCBF when the brain region is activated but not in the steady state.

  5. Glycine receptors mediate excitation of subplate neurons in neonatal rat cerebral cortex.

    PubMed

    Kilb, W; Hanganu, I L; Okabe, A; Sava, B A; Shimizu-Okabe, C; Fukuda, A; Luhmann, H J

    2008-08-01

    The development of the cerebral cortex depends on genetic factors and early electrical activity patterns that form immature neuronal networks. Subplate neurons (SPn) are involved in the construction of thalamocortical innervation, generation of oscillatory network activity, and in the proper formation of the cortical columnar architecture. Because glycine receptors play an important role during early corticogenesis, we analyzed the functional consequences of glycine receptor activation in visually identified SPn in neocortical slices from postnatal day 0 (P0) to P4 rats using whole cell and perforated patch-clamp recordings. In all SPn the glycinergic agonists glycine, beta-alanine, and taurine induced dose-dependent inward currents with the affinity for glycine being higher than that for beta-alanine and taurine. Glycine-induced responses were blocked by the glycinergic antagonist strychnine, but were unaffected by either the GABAergic antagonist gabazine, the N-methyl-d-aspartate-receptor antagonist d-2-amino-5-phosphonopentanoic acid, or picrotoxin and cyanotriphenylborate, antagonists of alpha-homomeric and alpha1-subunit-containing glycine receptors, respectively. Under perforated-patch conditions, glycine induced membrane depolarizations that were sufficient to trigger action potentials (APs) in most cells. Furthermore, glycine and taurine decreased the injection currents as well as the synaptic stimulation strength required to elicit APs, indicating that glycine receptors have a consistent excitatory effect on SPn. Inhibition of taurine transport and application of hypoosmolar solutions induced strychnine-sensitive inward currents, suggesting that taurine can act as a possible endogenous agonist on SPn. In summary, these results demonstrate that SPn express glycine receptors that mediate robust excitatory membrane responses during early postnatal development.

  6. Age-associated expression of erythropoietin and its receptor in rat spiral ganglion neurons and its association with neuronal apoptosis and hearing alterations

    PubMed Central

    Zhong, Cheng; Zhang, Xueyuan

    2016-01-01

    The present study aimed to determine the expression of erythropoietin (EPO) and the EPO receptor (EPOR) in spiral ganglion neurons (SGNs) in the inner ear of rats of various ages, and the associated neuronal apoptosis and hearing alterations. A total of 15 healthy rats (n=30 ears), were divided into three groups: i) A nominated infant group at post-natal day (PND) 12–14, ii) an adult group at PND 60 and iii) a 3-year postnatal aged group. Auditory brainstem response (ABR) measurements were performed on all rats. EPO and EPOR expression in the inner ear was detected by immunohistochemistry. In situ terminal deoxynucleotidyl transferase dUTP nick end labeling assays were performed to detect the apoptosis of SGNs. The average hearing thresholds of the ABR (decibels above normal hearing level) were 5.625±4.955 in the infant, 15.000±8.498 in the adult and 23.500±13.134 in the aged groups. Hearing thresholds for aged and adult rats increased significantly compared with infant rats. However, the difference in latencies of peak I was not significant (P>0.05). EPO in SGNs was detected during different developmental periods without significant alterations, but were reduced compared with Corti's organ or the stria vascularis. EPOR expression increased significantly from infant to adult stage, and this increased expression was maintained in the aged group. An age-associated increase in the apoptosis of SGNs was detected in all three groups (P=0.0347). The potential neuroprotective effects of EPO in SGNs may not be revealed during the aging process under natural conditions, and may be associated with spontaneous neuronal apoptosis and consequently, hearing diminution. However, the age-associated increase in EPOR in SGNs may exert a role in neuroprotection when necessary, for example in presbycusis. PMID:27959434

  7. Neuronal apoptosis inhibitory protein (NAIP) localizes to the cytokinetic machinery during cell division

    PubMed Central

    Abadía-Molina, Francisco; Morón-Calvente, Virginia; Baird, Stephen D.; Shamim, Fahad; Martín, Francisco; MacKenzie, Alex

    2017-01-01

    The neuronal apoptosis inhibitory protein (NAIP) is a constituent of the inflammasome and a key component of the innate immune system. Here we use immunofluorescence to position NAIP within the cytokinetic apparatus, contiguous to chromosomal passenger complex (CPC), Centralspindlin, PRC1 and KIF4A. During metaphase, NAIP accumulates in the mitotic spindle poles and is shown in spindle microtubules; in anaphase NAIP is detected in the middle of the central spindle. At the end of cytokinesis, NAIP is localized in the outlying region of the stem body, the center of the intercellular bridge formed between daughter cells prior to cellular abscission. We also describe the sustained presence of NAIP mRNA and protein throughout the cell cycle with a significant increase observed in the G2/M phase. Consistent with a role for NAIP in cytokinesis, NAIP overexpression in HeLa cells promotes the acquisition of a multinuclear phenotype. Conversely, NAIP siRNA gene silencing results in an apoptotic lethal phenotype. Our confocal and super resolution stimulated-emission-depletion (STED) examination of mammalian cell cytokinesis demonstrate a potential new role for NAIP in addition to anti-apoptotic and innate immunology functions. PMID:28059125

  8. Ginsenoside Rg1 Protects against Oxidative Stress-induced Neuronal Apoptosis through Myosin IIA-actin Related Cytoskeletal Reorganization

    PubMed Central

    Wang, Yan; Liu, Qian; Xu, Yingqiong; Zhang, Yuanyuan; Lv, Yanni; Tan, Yisha; Jiang, Nan; Cao, Guosheng; Ma, Xiaonan; Wang, Jingrong; Cao, Zhengyu; Yu, Boyang; Kou, Junping

    2016-01-01

    Oxidative stress-induced cytoskeletal dysfunction of neurons has been implicated as a crucial cause of cell apoptosis or death in the central nervous system (CNS) diseases, such as neurodegenerative and psychiatric diseases. The application of neuroprotectants rescuing the neurons from cytoskeletal damage and apoptosis can be a potential treatment for these CNS diseases. Ginsenoside Rg1 (Rg1), one of the major active components of ginseng, has been reported possessing notable neuroprotective activities. However, there is rare report about its effect on cytoskeleton and its undergoing mechanism. The current study is to reveal the regulatory effects of Rg1 on cytoskeletal and morphological lesion in oxidative stress-induced neuronal apoptosis. The results demonstrated that pre-treatment with Rg1 (0.1-10 μM) attenuated hydrogen peroxide (H2O2)-induced neuronal apoptosis and oxidative stress through reducing the intracellular reactive oxygen species (ROS) production and methane dicarboxylic aldehyde (MDA) level. The Rg1 treatment also abolished H2O2-induced morphological changes, including cell rounding, membrane blebbing, neurite retraction and nuclei condensation, which were generated by myosin IIA-actin interaction. These effects were mediated via the down-regulation of caspase-3, ROCK1 (Rho-associated kinase1) activation and myosin light chain (MLC, Ser-19) phosphorylation. Furthermore, inhibiting myosin II activity with blebbistatin partly blocked the neuroprotective effects of Rg1. The computer-aided homology modelling revealed that Rg1 preferentially positioned in the actin binding cleft of myosin IIA and might block the binding of myosin IIA to actin filaments. Accordingly, the neuroprotective mechanism of Rg1 is related to the activity that inhibits myosin IIA-actin interaction and the caspase-3/ROCK1/MLC signaling pathway. These findings put some insights into the unique neuroprotective properties of Rg1 associated with the regulation of myosin IIA

  9. Fractal dimension of apical dendritic arborization differs in the superficial and the deep pyramidal neurons of the rat cerebral neocortex.

    PubMed

    Puškaš, Nela; Zaletel, Ivan; Stefanović, Bratislav D; Ristanović, Dušan

    2015-03-04

    Pyramidal neurons of the mammalian cerebral cortex have specific structure and pattern of organization that involves the presence of apical dendrite. Morphology of the apical dendrite is well-known, but quantification of its complexity still remains open. Fractal analysis has proved to be a valuable method for analyzing the complexity of dendrite morphology. The aim of this study was to establish the fractal dimension of apical dendrite arborization of pyramidal neurons in distinct neocortical laminae by using the modified box-counting method. A total of thirty, Golgi impregnated neurons from the rat brain were analyzed: 15 superficial (cell bodies located within lamina II-III), and 15 deep pyramidal neurons (cell bodies situated within lamina V-VI). Analysis of topological parameters of apical dendrite arborization showed no statistical differences except in total dendritic length (p=0.02), indicating considerable homogeneity between the two groups of neurons. On the other hand, average fractal dimension of apical dendrite was 1.33±0.06 for the superficial and 1.24±0.04 for the deep cortical neurons, showing statistically significant difference between these two groups (p<0.001). In conclusion, according to the fractal dimension values, apical dendrites of the superficial pyramidal neurons tend to show higher structural complexity compared to the deep ones. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. Quantitation and morphological characterization of rapid axon and dendritic growth from single cerebral hemispheric neurons in hydrated collagen lattice culture.

    PubMed

    Coates, P W

    1986-02-01

    Quantitative and qualitative data are reported for single cerebral hemispheric neurons in a 3-dimensional hydrated collagen lattice (HCL) culture system. Individual neurons not in contact with other cells or cell processes, including synapses, rapidly displayed two morphologically distinct classes of processes that could be traced from origin to termination: long thin processes interpreted as being axons, and shorter tapering and sometimes branched processes interpreted as being dendrites. Axons and dendrites of single neurons that had at least one process longer than the cell body were measured on each of 3 days after plating using an image analysis system coupled to a phase-contrast microscope and a microcomputer. Mean lengths of axons and dendrites alone or combined as total new growth per neuron, increased 3- to 5-fold and were as high as 745, 694 and 1226 microns respectively after 3 days in HCL, although some individual axons measured over 1500 microns. Other indices of neuron growth and differentiation increased 1- to 5-fold including the number of primary processes, branch points, segments and growth cones. Phase-contrast microscopy, staining with Nissl and silver, and scanning and transmission electron microscopy demonstrated many single multipolar and other neurons with axons, dendrites and well-differentiated properties. The data show that individual central nervous system neurons have an inherent capacity to quickly express characteristic differentiated features and also to grow rapidly in HCL.

  11. TL-2 attenuates β-amyloid induced neuronal apoptosis through the AKT/GSK-3β/β-catenin pathway.

    PubMed

    Zhu, Xiaolei; Wang, Sulei; Yu, Linjie; Yang, Hui; Tan, Renxiang; Yin, Kailin; Jin, Jiali; Zhao, Hui; Guan, Dening; Xu, Yun

    2014-09-01

    β-amyloid (Aβ)-mediated neuronal apoptosis contributes to the progression of Alzheimer's disease (AD), although the exact mechanism remains unclear. This study aimed to investigate whether Dalesconol B (TL-2), a potent immunosuppressive agent with an unusual carbon skeleton, could inhibit Aβ-induced apoptosis in vitro and in vivo and to explore the underlying mechanisms. Aβ(1-42) was injected to bilateral hippocampus of mice to make the AD models in vivo. TL-2 was able to cross the blood-brain barrier and attenuate memory deficits in the AD mice. TL-2 also inhibited Aβ(1-42)-induced neuronal apoptosis in vitro and in vivo. In addition, TL-2 could activate the AKT/GSK-3β pathway, and inhibition of AKT and activation of GSK-3β partially eliminated the neuroprotective effects of TL-2. Furthermore, TL-2 induced the nuclear translocation of β-catenin and enhanced its transcriptional activity through the AKT/GSK-3β pathway to promote neuronal survival. These results suggest that TL-2 might be a potential drug for AD treatment.

  12. Inhibition of Mitochondrial Clearance and Cu/Zn-SOD Activity Enhance 6-Hydroxydopamine-Induced Neuronal Apoptosis.

    PubMed

    In, Sua; Hong, Chang-Won; Choi, Boyoung; Jang, Bong-Geum; Kim, Min-Ju

    2016-01-01

    Parkinson's disease (PD) is a common movement disorder among neurodegenerative diseases, involving neuronal cell death in the substantia nigra of the midbrain. Although mechanisms of cell death in PD have been studied, the exact molecular pathogenesis is still unclear. Here, we explore the relationship between two types of cell death, autophagy and apoptosis, which have been studied separately in parkinsonian mimetic model of 6-hydroxydopamine (6-OHDA). 6-OHDA induced autophagy firstly and then later inhibition of autophagy flux occurred with apoptosis. The apoptosis was prevented by treatment of pan-caspase inhibitor, zVAD-fmk (benzyloxycarbonyl-VAD-fluoromethylketone (zVAD)), or early phase inhibitor of autophagy, 3-methyladenine (3-MA), indicating that autophagic induction was followed by the apoptosis. Interestingly, late step inhibitor of autophagy, bafilomycin A1 (BafA), aggravated 6-OHDA-induced apoptosis. This was associated with mitochondrial abnormality such as the inhibition of damaged mitochondrial clearance and aberrant increase of extracellular oxygen consumption. Furthermore, treatment of BafA did not inhibit 6-OHDA-mediated superoxide formation but strongly reduced the hydrogen peroxide production to below basal levels, indicating failure from superoxide to hydrogen peroxide. These results were accompanied by a lowered expression and activity of copper/zinc superoxide dismutase (Cu/Zn-SOD) but not of manganese SOD (MnSOD) and catalase. Thus, the present study suggests that crosstalk among apoptosis, autophagy, and oxidative stress is a causative factor of 6-OHDA-induced neuronal death and provides a mechanistic understanding of PD pathogenesis.

  13. Topographic organization of serotonergic and dopaminergic neurons in the cerebral ganglia and their peripheral projection patterns in the head areas of the snail Helix pomatia.

    PubMed

    Hernádi, L; Elekes, K

    1999-08-23

    The distribution of monoaminergic neurons within the cerebral ganglia was investigated in the pulmonate snail Helix pomatia. Simultaneous serotonin and tyrosine hydroxylase double immunostaining revealed that the immunoreactive cell groups are concentrated in a putative monoaminergic center on the ventral surface of the cerebral ganglia. Simultaneous cobalt (Co)- and nickel (Ni)-lysine backfills of cerebral nerves were combined with 5, 6-dihydroxytryptamine pigment-labelling of serotonergic neurons, or with fluorescence immunocytochemistry of dopaminergic neurons. This showed that the serotonergic and dopaminergic cell groups can be divided into smaller subgroups on the basis of their axonal projections into different cerebral nerves. These subgroups show a topographic organization within the serotonergic and dopaminergic neuronal clusters. In the serotonergic system, the different regions of the head are represented in a rostrocaudal direction, whereas a caudorostral organization is characteristic for the dopaminergic system. No serotonin- or dopamine-immunoreative cell bodies but numerous fibers were observed in the head areas, indicating that these are innervated by cerebral monoaminergic neurons and show different innervation patterns. Serotonin-immunoreactive fibers mostly innervate muscle fibers, whereas dopamine-immunoreactive processes do not innervate effector cells, but terminate within the nerve branches of the head areas. On the basis of their innervation pattern, we suggest that dopaminergic neurons may take part in en route modulation of sensory afferent and efferent processes in an as yet unknown manner. The serotonergic neurons, on the other hand, may play a direct role in the modulation of muscle function. Copyright 1999 Wiley-Liss, Inc.

  14. Transplantation of mesenchymal stem cells promotes the functional recovery of the central nervous system following cerebral ischemia by inhibiting myelin-associated inhibitor expression and neural apoptosis.

    PubMed

    Feng, Nianping; Hao, Guang; Yang, Fenggang; Qu, Fujun; Zheng, Haihong; Liang, Songlan; Jin, Yonghua

    2016-05-01

    Cerebral ischemia, which may lead to cerebral hypoxia and damage of the brain tissue, is a leading cause of human mortality and adult disability. Mesenchymal stem cells (MSCs) are a class of adult progenitor cells with the ability to differentiate into multiple cell types. The transplantation of bone marrow-derived MSCs is a potential therapeutic strategy for cerebral ischemia. However, the underlying mechanism has yet to be elucidated. In the present study, primary MSCs were isolated from healthy rats, labeled and transplanted into the brains of middle cerebral artery occlusion rat models. The location of the labeled MSCs in the rat brains were determined by fluorescent microscopy, and the neurological functions of the rats were scored. Immunohistochemical analyses demonstrated that the protein expression levels of myelin-associated inhibitors of regeneration, including Nogo-A, oligodendrocyte myelin glycoprotein and myelin-associated glycoprotein, were decreased following transplantation of the bone marrow-derived MSCs. Furthermore, the mRNA expression levels of Capase-3 and B-cell lymphoma 2, as determined by reverse transcription-quantitative polymerase chain reactions, were downregulated and upregulated, respectively, in the MSC-transplanted rats; thus suggesting that neural apoptosis was inhibited. The results of the present study suggested that the transplantation of bone marrow-derived MSCs was able to promote the functional recovery of the central nervous system following cerebral ischemia. Accordingly, inhibitors targeting myelin-associated inhibitors and apoptosis may be of clinical significance for cerebral ischemia in the future.

  15. Brazilein inhibits neuronal inflammation induced by cerebral ischemia and oxygen-glucose deprivation through targeting NOD2 expression.

    PubMed

    Yan, Xiao-Jin; Chai, Yu-Shuang; Yuan, Zhi-Yi; Wang, Xin-Pei; Jiang, Jing-Fei; Lei, Fan; Xing, Dong-Ming; DU, Li-Jun

    2016-05-01

    Brazilein is reported to have immunosuppressive effect on cardiovascular and cerebral-vascular diseases. The essential roles of innate immunity in cerebral ischemia are increasingly identified, but no studies concerning the influence of brazilein on the innate immunity receptors have been reported. The present study was designed to investigate the regulation of NOD2 (Nucleotide-binding oligomerization domain-containing protein 2) by brazilein for its protection of neuron in cerebral ischemia in vivo and oxygen-glucose deprivation in vitro. The results showed that brazilein could reverse the elevated expression of NOD2 and TNFα (tumor necrosis factor alpha) elicited by cerebral ischemia and reperfusion. This reduction could also be detected in normal mice and C17.2 cells, indicating that this suppressive effect of brazilein was correlated with NOD2. The results from GFP reporter plasmid assay suggested brazilein inhibited NOD2 gene transcription. In conclusion, brazilein could attenuate NOD2 and TNFα expression in cerebral ischemia and NOD2 may be one possible target of brazilein for its immune suppressive effect in neuro-inflammation.

  16. Neuroprotective and axonal outgrowth-promoting effects of tetramethylpyrazine nitrone in chronic cerebral hypoperfusion rats and primary hippocampal neurons exposed to hypoxia.

    PubMed

    Zhang, Tao; Gu, Jianbo; Wu, Liangmiao; Li, Ning; Sun, Yewei; Yu, Pei; Wang, Yuqiang; Zhang, Gaoxiao; Zhang, Zaijun

    2017-05-15

    Chronic cerebral hypoperfusion is an important risk factor for vascular dementia and other brain dysfunctions, for which there are currently no effective medications available. We investigated the neuroprotective and axonal outgrowth promoting effects of tetramethylpyrazine nitrone (TBN) in a permanent bilateral occlusion of the common carotid arteries (2VO) rat model and in primary hippocampal neurons exposed to oxygen glucose deprivation (OGD). At 6th week after 2VO, TBN increased the time spent in novel arms in the Y-maze test and improved the discrimination ratio in object reorganization task. TBN attenuated axonal damage, and reduced oxidative DNA injury and lipid peroxidation in white matter. TBN also attenuated the neuronal apoptosis and ameliorated accumulation of astrocytes in parietal cortex and CA1 region of hippocampus. Western blot analyses indicated that TBN increased Bcl-2 expression, decreased Bax and Caspase 3 expressions, and upregulated the phosphorylation levels of high-molecular weight neurofilament (p-NFH), Akt (p-Akt) and glycogen synthase kinase-3β (p-GSK3β) in hippocampus at 6th week after chronic hypoperfusion. In vitro, TBN rescued hippocampal neuronal viability and axonal elongation from OGD damage. The p-Akt and p-GSK3β upregulation by TBN was abolished by a specific phosphoinositide 3-kinase (PI3K) inhibitor LY294002, resulting in suppression of axonal outgrowth. Collectively, the results showed that TBN alleviated white matter lesion and impairment of cortex and hippocampus, attenuated oxidative damage and enhanced axonal outgrowth through the regulation of PI3K/Akt/GSK3β signaling pathway, leading to improved cognitive deficit in a rat chronic hypoperfusion model. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Inhibitory effect of ganglioside GD1b on K+ current in hippocampal neurons and its involvement in apoptosis suppression.

    PubMed

    Chen, Xuesong; Chi, Shaopeng; Liu, Mingna; Yang, Wei; Wei, Taotao; Qi, Zhi; Yang, Fuyu

    2005-12-01

    Gangliosides are endogenous membrane components enriched in neuronal cells. They have been shown to play regulatory roles in many cellular processes. Here, we show for the first time that ganglioside GD1b plays an antiapoptotic role in cultured hippocampal neurons. GD1b inhibited the voltage-dependent outward delayed rectifier current (I(K)) but not the transient outward A-type current in a dose-dependent manner, with an IC50 value of 15.2 microM. This effect appears to be somehow specific, because GD1b, but not GM1, GM2, GM3, GD1a, GD3, or GT1b, was effective in inhibiting I(K). Intracellular application of staurosporine (STS; 0.1 microM) resulted in rapid activation of I(K), which was partially reversed upon addition of the K+ channel blocker tetraethylammonium (TEA; 5 mM) and GD1b (10 microM). Furthermore, GD1b (10 microM) attenuated STS-induced neuronal apoptosis by nearly the same amount as 5 mM TEA. In addition, GD1b suppressed the apoptosis-associated caspase 3 activation that was activated by STS. Collectively, these findings suggest that GD1b plays an antiapoptotic role in cultured hippocampal neurons through its inhibitory effect on the I(K) and caspase activity.

  18. The Expression of VHL (Von Hippel-Lindau) After Traumatic Spinal Cord Injury and Its Role in Neuronal Apoptosis.

    PubMed

    Hao, Jie; Chen, Xiaoqing; Fu, Ting; Liu, Jie; Yu, Mingchen; Han, Wei; He, Shuang; Qian, Rong; Zhang, Feng

    2016-09-01

    The VHL (Von Hippel-Lindau) gene is a tumor suppressor gene, which is best known as an E3 ubiquitin ligase that negatively regulates the hypoxia inducible factor. The inactivation of VHL gene could result in the abnormal synthesis of VHL protein, which is in contact with the development and occurrence of renal clear cell carcinoma. However, the expression and possible function of VHL in central nervous system (CNS) is still unclear. To examine the function of VHL in CNS injury and repair, we used an acute spinal cord injury (SCI) model in adult rats. Western blot analysis showed an important upregulation of VHL protein, reaching a peak at day 3 and then declined during the following days. Double immunofluorescence staining showed that VHL was co-expressed with neurons, but not with astrocytes and microglia. Moreover, we detected that active caspase-3 had co-localized with VHL in neurons after SCI. Additionally in vitro, VHL depletion, by short interfering RNA, significantly reduced neuronal apoptosis. In conclusion, these data suggested that the change of VHL protein expression was related to neuronal apoptosis after SCI.

  19. Effects of citicoline used alone and in combination with mild hypothermia on apoptosis induced by focal cerebral ischemia in rats.

    PubMed

    Sahin, S; Alkan, T; Temel, S G; Tureyen, K; Tolunay, S; Korfali, E

    2010-02-01

    The effects of citicoline used either alone or in combination with hypothermia on the suppression of apoptotic processes after transient focal cerebral ischemia were investigated. Middle cerebral artery occlusion (MCAo) was performed for 2 hours on Sprague-Dawley (SD) rats using intraluminal thread insertion. The treatment groups were as follows: Group 1, sham-operated; Group 2, saline; Group 3, citicoline (400mg/kg intraperitoneal.); Group 4, hypothermia (34+/-1 degrees C); Group 5, citicoline+hypothermia. All rats were reperfused for 24 hours, and after sacrifice and transcardiac perfusion, immunohistochemical studies were performed for markers of apoptosis. In Group 2, the Bcl-2 immunostaining score (mean+/-standard deviation, 0.71+/-0.75) was lower compared to Groups 3, 4 and 5 (2.33+/-0.81; 3.00+/-0.00; 2.20+/-0.83; p<0.05). There was higher expression of caspase-3 proteins in Group 2 (2.28+/-0.95) compared to Group 5 (1.50+/-0.83; p<0.05). Bax proteins were also increased in Group 2 (1.85+/-1.06) compared to Group 5 (0.40+/-0.54) and in Group 4 (2.00+/-0.00) compared to Group 5 (0.40+/-0.54; p<0.05). Significant differences in caspase-9 immunostaining scores were found in Group 2 (2.29+/-0.96) compared to Group 5 (0.20+/-0.44) (p<0.05); Group 3 (1.00+/-0.70) compared to Group 5 (0.20+/-0.44; p<0.05); and Group 4 (3.00+/-0.00; p<0.05) compared to Group 5 (0.40+/-0.54; p<0.05). Thus by suppressing apoptotic processes citicoline with hypothermia is more effective than either used alone in ameliorating cerebral damage after transient focal ischemia.

  20. Effects of prolonged abstinence from METH on the hippocampal BDNF levels, neuronal numbers and apoptosis in methamphetamine-sensitized rats.

    PubMed

    Hajheidari, Samira; Sameni, Hamid Reza; Bandegi, Ahmad Reza; Miladi-Gorji, Hossein

    2017-04-03

    Methamphetamine (METH) use is associated with neuronal damage in various regions of brain, while effects of prolonged abstinence on METH-induced damage are not quite clear. This study evaluated serum and hippocampal BDNF levels, neuronal numbers and apoptosis in METH-sensitized and abstinent rats. Rats were sensitized to METH (2mg/kg, daily/18 days, s.c.). All rats were evaluated for neuron counting, the TUNEL test and serum and hippocampal BDNF levels after 30 days of forced abstinence from METH. The results showed that increased BDNF levels in the hippocampus and serum of METH-sensitized rats returned to control level after 30 days of abstinence. The number of neurons in the DG and CA1 of hippocampus and also, the total hippocampal perimeter and area in METH-sensitized rats were significantly lower than the saline rats. While, the number of neurons was not significantly increased in the hippocampus after prolonged abstinence from METH. Also, METH-sensitized rats showed a significant increase in TUNEL-positive cells, whereas METH-abstinent rats showed a slight but significant decrease in TUNEL-positive cells in the DG and CA3 of hippocampus. These results suggest that despite the reduction in BDNF levels, reducing the number of neurons, perimeter and area of the hippocampus were stable after abstinence. Thus, the degenerative effects of METH have been sustained even after prolonged abstinence in the hippocampus. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Effects of ganoderic acids on epileptiform discharge hippocampal neurons: insights from alterations of BDNF,TRPC3 and apoptosis.

    PubMed

    Yang, Zhi-wei; Wu, Fei; Zhang, Sheng-Li

    2016-06-01

    Recently, Ganoderma lucidum spores (GLS) have shown anti-epileptic effects. However, there are no reports on the anti-epileptic effects of its chemical constituents ganoderic acids (GAs), and more research is needed to better understand the mechanism of GLS activity. In this work, rat primary hippocampal neurons in an in vitro model were used to assess the intervention effects of GAs on epileptiform discharge hippocampal neurons and expression of both BDNF and TRPC3, with the aid of immunofluorescence, MTT method and flow cytometry. It was found that BDNF and TRPC3 are expressed in all cells and were mainly localized in the cytoplasm. The fluorescence intensities of BDNF and TRPC3 in GAs groups were higher than those of normal control and model groups, especially at 80 μg/ml (P < 0.05). The apoptosis rate of neurons was inversely proportional to BDNF and TRPC3 changes (P < 0.01). Therefore, BDNF and TRPC3 should be involved in the occurrence and development of epilepsy. GAs might indirectly inhibit mossy fiber sprouting and adjust the synaptic reconstructions by promoting the expression of BDNF and TRPC3. Besides, GAs could exert a protective effect on hippocampal neurons by promoting neuronal survival and the recovery of injured neurons.

  2. Nerve growth factor receptor immunoreactivity is transiently associated with the subplate neurons of the mammalian cerebral cortex

    SciTech Connect

    Allendoerfer, K.L.; Shelton, D.L.; Shooter, E.M.; Shatz, C.J. )

    1990-01-01

    Nerve growth factor and its receptor (NGFR) are known to be present in diverse embryonic and neonatal central nervous system tissues, including the cerebral cortex. However, the identity of the cortical cells expressing NGFR immunoreactivity has not been established. We have used immunolabeling coupled with (3H)thymidine autoradiography to identify such cells in ferret and cat brain. Polyclonal antibodies raised against a synthetic peptide corresponding to a conserved amino acid sequence of the NGFR were used for this purpose. Western (immunologic) blot analyses show that these antibodies specifically recognize NGFR and precursor proteins. In both species, NGFR immunoreactivity is primarily associated with the early generated and transient subplate neuron population of the developing neocortex, as indicated by the following evidence: the immunoreactive cells (i) are located directly beneath the developing cortical plate, (ii) frequently have the inverted pyramid shape characteristic of subplate neurons, and (iii) can be labeled by an injection of (3H)thymidine on embryonic day (E) 28, a time when only subplate neurons are being generated. Intense NGFR immunostaining is seen on the cell bodies of these neurons as early as E30, several days after their last round of cell division, and this immunostaining remains strong for approximately 3 weeks. The NGFR immunoreactivity begins to decline around E52 and has disappeared from the region altogether by E60, at which time subplate neurons begin to die. The cellular localization and timing of expression suggest that the NGFR may play a role in the maintenance of subplate neurons and in the maturation of the cerebral cortex.

  3. Selective reduction of cerebral cortex GABA neurons in a late gestation model of fetal alcohol spectrum disorder.

    PubMed

    Smiley, John F; Saito, Mariko; Bleiwas, Cynthia; Masiello, Kurt; Ardekani, Babak; Guilfoyle, David N; Gerum, Scott; Wilson, Donald A; Vadasz, Csaba

    2015-09-01

    Fetal alcohol spectrum disorders (FASD) are associated with cognitive and behavioral deficits, and decreased volume of the whole brain and cerebral cortex. Rodent models have shown that early postnatal treatments, which mimic ethanol toxicity in the third trimester of human pregnancy, acutely induce widespread apoptotic neuronal degeneration and permanent behavioral deficits. However, the lasting cellular and anatomical effects of early ethanol treatments are still incompletely understood. This study examined changes in neocortex volume, thickness, and cellular organization that persist in adult mice after postnatal day 7 (P7) ethanol treatment. Post mortem brain volumes, measured by both MRI within the skull and by fluid displacement of isolated brains, were reduced 10-13% by ethanol treatment. The cerebral cortex showed a similar reduction (12%) caused mainly by lower surface area (9%). In spite of these large changes, several features of cortical organization showed little evidence of change, including cortical thickness, overall neuron size, and laminar organization. Estimates of total neuron number showed a trend level reduction of about 8%, due mainly to reduced cortical volume but unchanged neuron density. However, counts of calretinin (CR) and parvalbumin (PV) subtypes of GABAergic neurons showed a striking >30% reduction of neuron number. Similar ethanol effects were found in male and female mice, and in C57BL/6By and BALB/cJ mouse strains. Our findings indicate that the cortex has substantial capacity to develop normal cytoarchitectonic organization after early postnatal ethanol toxicity, but there is a selective and persistent reduction of GABA cells that may contribute to the lasting cognitive and behavioral deficits in FASD.

  4. Selective reduction of cerebral cortex GABA neurons in a late gestation model of fetal alcohol spectrum disorder

    PubMed Central

    Smiley, John F.; Saito, Mariko; Bleiwas, Cynthia; Masiello, Kurt; Ardekani, Babak; Guilfoyle, David N.; Gerum, Scott; Wilson, Donald A.; Vadasz, Csaba

    2015-01-01

    Fetal alcohol spectrum disorders (FASD) are associated with cognitive and behavioral deficits, and decreased volume of the whole brain and cerebral cortex. Rodent models have shown that early postnatal treatments, which mimic ethanol toxicity in the third trimester of human pregnancy, acutely induce widespread apoptotic neuronal degeneration and permanent behavioral deficits. However, the lasting cellular and anatomical effects of early ethanol treatments are still incompletely understood. This study examined changes in neocortex volume, thickness, and cellular organization that persist in adult mice after postnatal day 7 (P7) ethanol treatment. Post mortem brain volumes, measured by both MRI within the skull and by fluid displacement of isolated brains, were reduced 10–13% by ethanol treatment. The cerebral cortex showed a similar reduction (12%) caused mainly by lower surface area (9%). In spite of these large changes, several features of cortical organization showed little evidence of change, including cortical thickness, overall neuron size, and laminar organization. Estimates of total neuron number showed a trend level reduction of about 8%, due mainly to reduced cortical volume but unchanged neuron density. However, counts of calretinin (CR) and parvalbumin (PV) subtypes of GABAergic neurons showed a striking >30% reduction of neuron number. Similar ethanol effects were found in male and female mice, and in C57BL/6By and BALB/cJ mouse strains. Our findings indicate that the cortex has substantial capacity to develop normal cytoarchitectonic organization after early postnatal ethanol toxicity, but there is a selective and persistent reduction of GABA cells that may contribute to the lasting cognitive and behavioral deficits in FASD. PMID:26252988

  5. Ischemic postconditioning alleviates neuronal injury caused by relief of carotid stenosis in a rat model of cerebral hypoperfusion.

    PubMed

    Feng, Chunsheng; Luo, Tianfei; Qi, Li; Wang, Boyu; Luo, Yinan; Ge, Pengfei

    2012-10-18

    The effects of early relief of heavy bilateral carotid stenosis and ischemic postconditioning on hippocampus CA1 neurons are still unclear. In this study, we used a rat model to imitate severe bilateral carotid stenosis in humans. The rats were divided into sham group, carotid stenosis group, stenosis relief group and ischemic postconditioning group. Ischemic postconditioning consisted of three cycles of 30 s ischemia and 30 s reperfusion. The cerebral blood flow was measured with a laser Doppler flowmeter. Neuronal death in the CA1 region was observed by hematoxylin-eosin staining, and the number of live neurons was assessed by cell counting under a light microscope. The levels of oxidative products MDA and 8-iso-PGF2α, inflammatory factors IL-1β and TNF-α, and the activities of anti-oxidative enzymes SOD and CAT were assayed by specific enzyme-linked immunosorbent assay (ELISA) kits, respectively. We found that relief of carotid stenosis and ischemic postconditioning could increase cerebral blood flow. When stenosis was relieved, the percentage of live neurons was 66.6% ± 6.2% on day 3 and 62.3% ± 9.8% on day 27, which was significantly higher than 55.5% ± 4.8% in stenosis group. Ischemic postconditioning markedly improved the live neurons to 92.5% ± 6.7% on day 3 and 88.6% ± 9.1% on day 27. Further study showed that, neuronal death caused by relief of stenosis is associated with increased oxidative stress and enhanced inflammatory response, and the protection of ischemic postconditioning is related to inhibition of oxidative stress and suppression of inflammatory response.

  6. Optical inhibition of striatal neurons promotes focal neurogenesis and neurobehavioral recovery in mice after middle cerebral artery occlusion.

    PubMed

    He, Xiaosong; Lu, Yifan; Lin, Xiaojie; Jiang, Lu; Tang, Yaohui; Tang, Guanghui; Chen, Xiaoyan; Zhang, Zhijun; Wang, Yongting; Yang, Guo-Yuan

    2017-03-01

    Striatal neurons regulate the activity of neural progenitor cells in the subventricular zone, but the effect of striatal neuronal activity on neurogenesis after ischemic stroke is unclear. In this study, we used optogenetic tools to investigate the impact of striatal neuronal activity on the neurogenesis and functional recovery after cerebral ischemia. We transfected striatal neurons with channelrhodopsin-2 or halorhodopsin from Natronomonas so that they can be excited by 473 nm laser or inhibited by 594 nm laser, respectively. Neural inhibition but not excitation at 4-7 days after middle cerebral artery occlusion resulted in reduced atrophy volume (6.8 ± 0.7 vs 8.5 ± 1.2 mm(3), p < 0.05) and better performance represented by longer sustaining time on rotarod (99.3 ± 9 vs 80.1 ± 11 s, p < 0.01) and faster moving speed (7.7 ± 2 vs 5.7 ± 1.1 cm/s, p < 0.05) in open field tests. Furthermore, neural inhibition increased the number of nestin(+), BrdU(+)/doublecortin(+) and BrdU(+)/NeuN(+) cells ( p < 0.001) in the subventricular zone and peri-focal region, and the expression level of axon guidance factor Netrin-1 (0.39 ± 0.16 vs 0.16 ± 0.02, p < 0.05) in the peri-focal region. These data suggest that striatal neuronal activity plays an important role in regulating neurogenesis and neural-behavioral outcomes, and that inhibiting striatal neurons by optogenetics promotes the recovery after ischemic stroke in mice.

  7. Primary culture and characteristic morphologies of neurons from the cerebral ganglion of the mud crab, Scylla paramamosain.

    PubMed

    Xu, Yan; Ye, Haihui; Ma, Jun; Huang, Huiyang; Wang, Guizhong

    2010-09-01

    Crustacean neurons, obtained from the cerebral ganglion of the mud crab Scylla paramamosain, were successfully cultured in vitro. They maintained typical morphological characteristics and showed better outgrowth in modified Medium 199 (M199) medium than that in Liebowitz's L-15 medium. Fetal bovine serum (FBS), muscle extracts, and hemolymph of the mud crab S. paramamosain were added as supplements. Only 20% FBS could promote neuron outgrowth, while muscle extracts and hemolymph of S. paramamosain did not improve neuron outgrowth. For cell dissociation, both collagenase type I and trypsin worked well as determined by initial cell viability and following cell outgrowth potential. More than six kinds of cells with different morphological characteristics were identified in the neuron outgrowth. They were "small cells", "veilers", "branchers", "multipolar cells", "super-large cell", and "bipolar cells". Among all of the cells, bipolar cells were identified for the first time in crustacean neurons culture and they could live longer than other cells. The neurons could grow for more than a week before retraction and eventual degradation.

  8. Deciphering the Neuronal Circuitry Controlling Local Blood Flow in the Cerebral Cortex with Optogenetics in PV::Cre Transgenic Mice

    PubMed Central

    Urban, Alan; Rancillac, Armelle; Martinez, Lucie; Rossier, Jean

    2012-01-01

    Although it is know since more than a century that neuronal activity is coupled to blood supply regulation, the underlying pathways remains to be identified. In the brain, neuronal activation triggers a local increase of cerebral blood flow (CBF) that is controlled by the neurogliovascular unit composed of terminals of neurons, astrocytes, and blood vessel muscles. It is generally accepted that the regulation of the neurogliovascular unit is adjusted to local metabolic demand by local circuits. Today experimental data led us to realize that the regulatory mechanisms are more complex and that a neuronal system within the brain is devoted to the control of local brain-blood flow. Recent optogenetic experiments combined with functional magnetic resonance imaging have revealed that light stimulation of neurons expressing the calcium binding protein parvalbumin (PV) is associated with positive blood oxygen level-dependent (BOLD) signal in the corresponding barrel field but also with negative BOLD in the surrounding deeper area. Here, we demonstrate that in acute brain slices, channelrhodopsin-2 (ChR2) based photostimulation of PV containing neurons gives rise to an effective contraction of penetrating arterioles. These results support the neurogenic hypothesis of a complex distributed nervous system controlling the CBF. PMID:22715327

  9. Gallium nitride induces neuronal differentiation markers in neural stem/precursor cells derived from rat cerebral cortex.

    PubMed

    Chen, Chi-Ruei; Li, Yi-Chen; Young, Tai-Horng

    2009-09-01

    In the present study, gallium nitride (GaN) was used as a substrate to culture neural stem/precursor cells (NSPCs), isolated from embryonic rat cerebral cortex, to examine the effect of GaN on the behavior of NSPCs in the presence of basic fibroblast growth factor (bFGF) in serum-free medium. Morphological studies showed that neurospheres maintained their initial shape and formed many long and thick processes with the fasciculate feature on GaN. Immunocytochemical characterization showed that GaN could induce the differentiation of NSPCs into neurons and astrocytes. Compared to poly-d-lysine (PDL), the most common substrate used for culturing neurons, there was considerable expression of synapsin I for differentiated neurons on GaN, suggesting GaN could induce the differentiation of NSPCs towards the mature differentiated neurons. Western blot analysis showed that the suppression of glycogen synthase kinase-3beta (GSK-3beta) activity was one of the effects of GaN-promoted NSPC differentiation into neurons. Finally, compared to PDL, GaN could significantly improve cell survival to reduce cell death after long-term culture. These results suggest that GaN potentially has a combination of electric characteristics suitable for developing neuron and/or NSPC chip systems.

  10. Upregulation of mitochondrial protease HtrA2/Omi contributes to manganese-induced neuronal apoptosis in rat brain striatum.

    PubMed

    Jiang, J K; Ma, X; Wu, Q Y; Qian, W B; Wang, N; Shi, S S; Han, J L; Zhao, J Y; Jiang, S Y; Wan, C H

    2014-05-30

    Manganese (Mn) is an essential trace element that is required for normal brain functioning. However, excessive intake of Mn has been known to lead to neuronal loss and clinical symptoms resembling idiopathic Parkinson's disease (IPD), whose precise molecular mechanism remains largely elusive. In the study, we established a Mn-exposed rat model and identified a mitochondrial protease, the mature form of high temperature requirement A2 (HtrA2/Omi), which was significantly upregulated in rat brain striatum after Mn exposure. Western blot and immunohistochemical analyses revealed that the expression of mature HtrA2 was remarkably increased following Mn exposure. In addition, immunofluorescence assay demonstrated that overexposure to Mn could lead to significant elevation in the number of HtrA2-positive neurons. Accordingly, the expression of X-linked inhibitor of apoptosis protein (XIAP), a well-characterized target of HtrA2-mediated proteolysis, was progressively decreased following Mn exposure, and was correlated with increased level of active caspase-3. Further, we showed that Mn exposure decreased the viability and induced apparent apoptosis of NFG-differentiated PC12 cells. Importantly, the expression of HtrA2 was progressively increased, whereas the level of cellular XIAP was reduced during Mn-induced apoptosis. In addition, blockage of HtrA2 activity with UCF-101 restored Mn-induced reduction in XIAP expression. Finally, we observed that UCF-101 treatment ameliorated Mn-induced apoptosis in PC12 cells. Collectively, these findings suggested that upregulated HtrA2 played a role in Mn-induced neuronal death in brain striatum.

  11. Mutations in CRADD Result in Reduced Caspase-2-Mediated Neuronal Apoptosis and Cause Megalencephaly with a Rare Lissencephaly Variant.

    PubMed

    Di Donato, Nataliya; Jean, Ying Y; Maga, A Murat; Krewson, Briana D; Shupp, Alison B; Avrutsky, Maria I; Roy, Achira; Collins, Sarah; Olds, Carissa; Willert, Rebecca A; Czaja, Agnieszka M; Johnson, Rachel; Stover, Jessi A; Gottlieb, Steven; Bartholdi, Deborah; Rauch, Anita; Goldstein, Amy; Boyd-Kyle, Victoria; Aldinger, Kimberly A; Mirzaa, Ghayda M; Nissen, Anke; Brigatti, Karlla W; Puffenberger, Erik G; Millen, Kathleen J; Strauss, Kevin A; Dobyns, William B; Troy, Carol M; Jinks, Robert N

    2016-11-03

    Lissencephaly is a malformation of cortical development typically caused by deficient neuronal migration resulting in cortical thickening and reduced gyration. Here we describe a "thin" lissencephaly (TLIS) variant characterized by megalencephaly, frontal predominant pachygyria, intellectual disability, and seizures. Trio-based whole-exome sequencing and targeted re-sequencing identified recessive mutations of CRADD in six individuals with TLIS from four unrelated families of diverse ethnic backgrounds. CRADD (also known as RAIDD) is a death-domain-containing adaptor protein that oligomerizes with PIDD and caspase-2 to initiate apoptosis. TLIS variants cluster in the CRADD death domain, a platform for interaction with other death-domain-containing proteins including PIDD. Although caspase-2 is expressed in the developing mammalian brain, little is known about its role in cortical development. CRADD/caspase-2 signaling is implicated in neurotrophic factor withdrawal- and amyloid-β-induced dendritic spine collapse and neuronal apoptosis, suggesting a role in cortical sculpting and plasticity. TLIS-associated CRADD variants do not disrupt interactions with caspase-2 or PIDD in co-immunoprecipitation assays, but still abolish CRADD's ability to activate caspase-2, resulting in reduced neuronal apoptosis in vitro. Homozygous Cradd knockout mice display megalencephaly and seizures without obvious defects in cortical lamination, supporting a role for CRADD/caspase-2 signaling in mammalian brain development. Megalencephaly and lissencephaly associated with defective programmed cell death from loss of CRADD function in humans implicate reduced apoptosis as an important pathophysiological mechanism of cortical malformation. Our data suggest that CRADD/caspase-2 signaling is critical for normal gyration of the developing human neocortex and for normal cognitive ability.

  12. Neurotrophic effects of GnRH on neurite outgrowth and neurofilament protein expression in cultured cerebral cortical neurons of rat embryos.

    PubMed

    Quintanar, J Luis; Salinas, Eva

    2008-06-01

    The presence of GnRH receptor in cerebral cortical neurons of rat embryos and adult rats has been described. In this work, we studied the effects of GnRH on outgrowth and length of neurites and cytoskeletal neurofilament proteins expression (NF-68 and NF-200 kDa) by immunoblot of cultured cerebral cortical neurons of rat embryos. Our results show that GnRH increases both outgrowth and length of neurites accompanied by an increase in neurofilaments expression. It is conceivable that GnRH plays a role in neuronal plasticity parallel to its gonadal function.

  13. Bovine Herpes Virus 1 (BHV-1) and Herpes Simplex Virus Type 1 (HSV-1) Promote Survival of Latently Infected Sensory Neurons, in Part by Inhibiting Apoptosis

    PubMed Central

    Jones, Clinton

    2013-01-01

    α-Herpesvirinae subfamily members, including herpes simplex virus type 1 (HSV-1) and bovine herpes virus 1 (BHV-1), initiate infection in mucosal surfaces. BHV-1 and HSV-1 enter sensory neurons by cell-cell spread where a burst of viral gene expression occurs. When compared to non-neuronal cells, viral gene expression is quickly extinguished in sensory neurons resulting in neuronal survival and latency. The HSV-1 latency associated transcript (LAT), which is abundantly expressed in latently infected neurons, inhibits apoptosis, viral transcription, and productive infection, and directly or indirectly enhances reactivation from latency in small animal models. Three anti-apoptosis genes can be substituted for LAT, which will restore wild type levels of reactivation from latency to a LAT null mutant virus. Two small non-coding RNAs encoded by LAT possess anti-apoptosis functions in transfected cells. The BHV-1 latency related RNA (LR-RNA), like LAT, is abundantly expressed during latency. The LR-RNA encodes a protein (ORF2) and two microRNAs that are expressed in certain latently infected neurons. Wild-type expression of LR gene products is required for stress-induced reactivation from latency in cattle. ORF2 has anti-apoptosis functions and interacts with certain cellular transcription factors that stimulate viral transcription and productive infection. ORF2 is predicted to promote survival of infected neurons by inhibiting apoptosis and sequestering cellular transcription factors which stimulate productive infection. In addition, the LR encoded microRNAs inhibit viral transcription and apoptosis. In summary, the ability of BHV-1 and HSV-1 to interfere with apoptosis and productive infection in sensory neurons is crucial for the life-long latency-reactivation cycle in their respective hosts. PMID:25278776

  14. Bovine Herpes Virus 1 (BHV-1) and Herpes Simplex Virus Type 1 (HSV-1) Promote Survival of Latently Infected Sensory Neurons, in Part by Inhibiting Apoptosis.

    PubMed

    Jones, Clinton

    2013-01-01

    α-Herpesvirinae subfamily members, including herpes simplex virus type 1 (HSV-1) and bovine herpes virus 1 (BHV-1), initiate infection in mucosal surfaces. BHV-1 and HSV-1 enter sensory neurons by cell-cell spread where a burst of viral gene expression occurs. When compared to non-neuronal cells, viral gene expression is quickly extinguished in sensory neurons resulting in neuronal survival and latency. The HSV-1 latency associated transcript (LAT), which is abundantly expressed in latently infected neurons, inhibits apoptosis, viral transcription, and productive infection, and directly or indirectly enhances reactivation from latency in small animal models. Three anti-apoptosis genes can be substituted for LAT, which will restore wild type levels of reactivation from latency to a LAT null mutant virus. Two small non-coding RNAs encoded by LAT possess anti-apoptosis functions in transfected cells. The BHV-1 latency related RNA (LR-RNA), like LAT, is abundantly expressed during latency. The LR-RNA encodes a protein (ORF2) and two microRNAs that are expressed in certain latently infected neurons. Wild-type expression of LR gene products is required for stress-induced reactivation from latency in cattle. ORF2 has anti-apoptosis functions and interacts with certain cellular transcription factors that stimulate viral transcription and productive infection. ORF2 is predicted to promote survival of infected neurons by inhibiting apoptosis and sequestering cellular transcription factors which stimulate productive infection. In addition, the LR encoded microRNAs inhibit viral transcription and apoptosis. In summary, the ability of BHV-1 and HSV-1 to interfere with apoptosis and productive infection in sensory neurons is crucial for the life-long latency-reactivation cycle in their respective hosts.

  15. Lycium barbarum polysaccharide improves traumatic cognition via reversing imbalance of apoptosis/regeneration in hippocampal neurons after stress.

    PubMed

    Gao, Jie; Chen, Can; Liu, Yuan; Li, Yingyu; Long, Zaiyun; Wang, He; Zhang, Yundong; Sui, Jianfeng; Wu, Yamin; Liu, Liangming; Yang, Ce

    2015-01-15

    Previous studies in our laboratory have demonstrated the increased neuronal apoptosis in the hippocampus and abnormal hippocampal morphology after severe stress, which directly correlates to the pathogenesis of post-traumatic stress disorder (PTSD). This study aims to investigate the effects of Lycium barbarum polysaccharide (LBP) on intrusive memory of posttraumatic stress in rats, and to analyze the mechanism of regeneration/apoptosis balance in the hippocampal neurons. The experimental rats received 20 inescapable electric foot shocks in an enclosed box for six times in three days. The rats were treated by intragastric administration of LBP (20mg/kg/day) for 3 days before stress in the stress plus prophylactic group, and for 28 days after stress in the stress plus therapeutic group. The emotion, intrusive memory-related behavior (freezing, open field, pain latency, spatial cognition), hippocampus cell morphology, and relation of neurogenesis and apoptosis in dental gyrus of the hippocampus were observed. The hippocampus volume was evaluated by stereology. Meanwhile, the neurogenesis and apoptosis were analyzed with 5-bromo-2'-deoxyuridine and terminal deoxylnucleotidyl transferase mediated-dUTP nick end labeling (TUNEL) method. The treatment of LBP in pre-stress and post-stress had obvious beneficial effect on the behaviors and neurogenesis. The stressed rats showed improvement of intrusive memory related cognition defect, alleviation of the apoptosis in the hippocampus and recovery for the neurogenesis, which was related to the hippocampus volume after LBP treatment. LBP treatment might effectively improve the traumatic cognition defect induced by severe stress and be useful for the intrusive memory-related cognition recovery. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Up-regulation of GBP2 is Associated with Neuronal Apoptosis in Rat Brain Cortex Following Traumatic Brain Injury.

    PubMed

    Miao, Qi; Ge, Meihong; Huang, Lili

    2017-02-27

    Guanylate binding protein 2 (GBP2) is one member of GBP family. Recently, GBP2 has been proposed to be a novel target of anti-cancer drugs. However, the role of GBP2 in the traumatic brain injury (TBI) is very limited. In this study, we sought to define GBP2's role in brain injury. GBP2 protein levels were significantly increased in the brain 3 days after injury, suggesting a functional role for GBP2 in TBI. Neuronal cells overexpressing GBP2 exhibited up-regulation of co-location of GBP2 and NeuN following TBI, suggesting that GBP2 potentiates the neuron apoptosis. To confirm the role of GBP2 in neuron apoptosis process, we employed a highly potent inhibitor of GBP2 (GBP2 RNAi). In H2O2-stimulated PC12 cells, in vitro blockade of GBP2 activity using GBP2 RNAi markedly attenuated the neuron apoptosis number. GBP2 RNAi also inhibited the expression levels of active caspase3 and p-Stat1. Furthermore, we found the expression of p-Stat1 in line with GBP2 and GBP2 interacted with p-Stat1 following TBI. The Jak2 inhibitor, AG490 inhibited this interaction and decreased the active caspase3 expression as well as promoted the functional recovery. Taken together, these data suggest that GBP2 RNAi has a protective effect in a rat TBI. This study demonstrates that GBP2 is an important positive regulator of TBI and is a promising therapeutic target for brain injury.

  17. Age-related changes in ultrastructural features of cathepsin B- and D-containing neurons in rat cerebral cortex.

    PubMed

    Jung, H; Lee, E Y; Lee, S I

    1999-10-09

    The present study examines age-related changes in the subcellular localization of cathepsin B (cath B) and cathepsin D (cath D), as well as morphological features of the cathepsin-immunoreactive (ir) neurons in rat cerebral cortex. Sprague-Dawley rats were studied at 3 and 26 months. By immunoelectron microscopy cath B- or cath D-immunoreactivities were found in many, but not all, pyramidal neurons. In young rat cerebral cortical neurons, cath B was observed not only in lysosomal systems such as multivesicular bodies, dense bodies, and lipofuscin granules, but also in extralysosomal sites. By contrast, cath D was confined mainly to lysosomal systems in young rats. In aged rats, cath B showed a similar pattern in its subcellular localization compared to the young control, but some of the dense bodies containing cath B was closely apposed to the outer nuclear envelope. These cells exhibited a relatively normal appearance. Regardless of subcellular localization, approximately 10% of cath B-ir neurons displayed ultrastructural disturbances presumed to indicate an early stage of degeneration. The nucleus was indented, nuclear boundary was indistinct, nuclear pore structures appeared separately with high frequency, and the endoplasmic reticulum appeared to be affected. In addition to its presence in lysosomal structures, cath D-immunoreactivity in aged cerebral cortex was noted prominently in the cytosol as diffuse granules. About 37% of cath D-ir cells showed this age-related change. Among the neurons with the diffusely scattered form of cath D, approximately 70% of cells exhibited the degenerating features. These cells were characterized by large amounts of diffuse cath D, reduced cellular size, loss of the nuclear boundary, scattered nuclear pore structures, an often fragmentation of the nucleus, disturbances of endoplasmic reticular system, and in advanced stages, condensed nucleus and poor preservation of almost cytoplasmic organelles. Though some of these features

  18. Neuroprotective Effects of Inhibiting Fyn S-Nitrosylation on Cerebral Ischemia/Reperfusion-Induced Damage to CA1 Hippocampal Neurons

    PubMed Central

    Hao, Lingyun; Wei, Xuewen; Guo, Peng; Zhang, Guangyi; Qi, Suhua

    2016-01-01

    Nitric oxide (NO) can regulate signaling pathways via S-nitrosylation. Fyn can be post-translationally modified in many biological processes. In the present study, using a rat four-vessel-occlusion ischemic model, we aimed to assess whether Fyn could be S-nitrosylated and to evaluate the effects of Fyn S-nitrosylation on brain damage. In vitro, Fyn could be S-nitrosylated by S-nitrosoglutathione (GSNO, an exogenous NO donor), and in vivo, endogenous NO synthesized by NO synthases (NOS) could enhance Fyn S-nitrosylation. Application of GSNO, 7-nitroindazole (7-NI, an inhibitor of neuronal NOS) and hydrogen maleate (MK-801, the N-methyl-d-aspartate receptor (NMDAR) antagonist) could decrease the S-nitrosylation and phosphorylation of Fyn induced by cerebral ischemia/reperfusion (I/R). Cresyl violet staining validated that these compounds exerted neuroprotective effects against the cerebral I/R-induced damage to hippocampal CA1 neurons. Taken together, in this study, we demonstrated that Fyn can be S-nitrosylated both in vitro and in vivo and that inhibiting S-nitrosylation can exert neuroprotective effects against cerebral I/R injury, potentially via NMDAR-mediated mechanisms. These findings may lead to a new field of inquiry to investigate the underlying pathogenesis of stroke and the development of novel treatment strategies. PMID:27420046

  19. Neuroprotective Effects of Inhibiting Fyn S-Nitrosylation on Cerebral Ischemia/Reperfusion-Induced Damage to CA1 Hippocampal Neurons.

    PubMed

    Hao, Lingyun; Wei, Xuewen; Guo, Peng; Zhang, Guangyi; Qi, Suhua

    2016-07-12

    Nitric oxide (NO) can regulate signaling pathways via S-nitrosylation. Fyn can be post-translationally modified in many biological processes. In the present study, using a rat four-vessel-occlusion ischemic model, we aimed to assess whether Fyn could be S-nitrosylated and to evaluate the effects of Fyn S-nitrosylation on brain damage. In vitro, Fyn could be S-nitrosylated by S-nitrosoglutathione (GSNO, an exogenous NO donor), and in vivo, endogenous NO synthesized by NO synthases (NOS) could enhance Fyn S-nitrosylation. Application of GSNO, 7-nitroindazole (7-NI, an inhibitor of neuronal NOS) and hydrogen maleate (MK-801, the N-methyl-d-aspartate receptor (NMDAR) antagonist) could decrease the S-nitrosylation and phosphorylation of Fyn induced by cerebral ischemia/reperfusion (I/R). Cresyl violet staining validated that these compounds exerted neuroprotective effects against the cerebral I/R-induced damage to hippocampal CA1 neurons. Taken together, in this study, we demonstrated that Fyn can be S-nitrosylated both in vitro and in vivo and that inhibiting S-nitrosylation can exert neuroprotective effects against cerebral I/R injury, potentially via NMDAR-mediated mechanisms. These findings may lead to a new field of inquiry to investigate the underlying pathogenesis of stroke and the development of novel treatment strategies.

  20. Calpain-2/p35-p25/Cdk5 pathway is involved in the neuronal apoptosis induced by polybrominated diphenyl ether-153.

    PubMed

    Zhang, Hongmei; Chang, Lijun; Zhang, Huajun; Nie, Jisheng; Zhang, Zhihong; Yang, Xiaorong; Vuong, Ann M; Wang, Zemin; Chen, Aimin; Niu, Qiao

    2017-08-05

    Polybrominated diphenyl ethers (PBDEs) have been demonstrated to induce neurotoxicity in experimental rats and mice, with neuronal apoptosis as one of the major mechanisms, however, the mechanisms underlying PBDEs-induced neuronal apoptosis remain unclear. In this study, we aimed to investigate the role of calpain/p35-p25/Cdk5 pathway in BDE-153-induced neuronal apoptosis in the hippocampus and primary neurons in rats. Results showed that compared to the controls, neuronal apoptosis was significantly increased in vivo and ex vivo, as manifested by the increased hippocampus TUNEL-positive cell rates, apoptotic neurons in Hoechst and AO/EB staining, and the increased LDH activity and percentage of Annexin V-positive cells in rat hippocampus and primary neurons. Calpain activity was significantly increased in all the BDE-153-treated groups in vivo and ex vivo when compared to non-treatment controls. In addition, we showed that calpain-2 accounted for the calpain activation instead of calpain-1, as demonstrated by the up-regulated mRNA and protein expressions in calpain-2 but not calpain-1. Activated calpain truncated p35 into p25, which resulted in the p25/Cdk5 formation and activation. Calpain inhibitor PD150606 or p25/Cdk5 inhibitor Roscovitine relieved neuronal apoptosis mainly via inhibiting the p25/Cdk5 activation. Overall, the findings suggested that calpain-2/p35-p25/Cdk5 pathway was involved in BDE-153-induced neuronal apoptosis, which provides novel insight into the mechanisms of PBDE neurotoxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. TNFR1 mediates increased neuronal membrane EAAT3 expression after in vivo cerebral ischemic preconditioning.

    PubMed

    Pradillo, J M; Hurtado, O; Romera, C; Cárdenas, A; Fernández-Tomé, P; Alonso-Escolano, D; Lorenzo, P; Moro, M A; Lizasoain, I

    2006-01-01

    A short ischemic event (ischemic preconditioning) can result in subsequent resistance to severe ischemic injury (ischemic tolerance). Glutamate is released after ischemia and produces cell death. It has been described that after ischemic preconditioning, the release of glutamate is reduced. We have shown that an in vitro model of ischemic preconditioning produces upregulation of glutamate transporters which mediates brain tolerance. We have now decided to investigate whether ischemic preconditioning-induced glutamate transporter upregulation takes also place in vivo, its cellular localization and the mechanisms by which this upregulation is controlled. A period of 10 min of temporary middle cerebral artery occlusion was used as a model of ischemic preconditioning in rat. EAAT1, EAAT2 and EAAT3 glutamate transporters were found in brain from control animals. Ischemic preconditioning produced an up-regulation of EAAT2 and EAAT3 but not of EAAT1 expression. Ischemic preconditioning-induced increase in EAAT3 expression was reduced by the TNF-alpha converting enzyme inhibitor BB1101. Intracerebral administration of either anti-TNF-alpha antibody or of a TNFR1 antisense oligodeoxynucleotide also inhibited ischemic preconditioning-induced EAAT3 up-regulation. Immunohistochemical studies suggest that, whereas the expression of EAAT3 is located in both neuronal cytoplasm and plasma membrane, ischemic preconditioning-induced up-regulation of EAAT3 is mainly localized at the plasma membrane level. In summary, these results demonstrate that in vivo ischemic preconditioning increases the expression of EAAT2 and EAAT3 glutamate transporters the upregulation of the latter being at least partly mediated by TNF-alpha converting enzyme/TNF-alpha/TNFR1 pathway.

  2. The Mechanism of Long Non-coding RNA MEG3 for Neurons Apoptosis Caused by Hypoxia: Mediated by miR-181b-12/15-LOX Signaling Pathway

    PubMed Central

    Liu, Xiaomin; Hou, Lijing; Huang, Weiwei; Gao, Yuan; Lv, Xin; Tang, Jiyou

    2016-01-01

    Objective: lncRNAs are recently thought to play a significant role in cellular homeostasis during pathological process of diseases by competing inhibiting miRNA function. The aim of present study was to assess the function of long non-coding RNA (lncRNA) MEG3 and its functional interaction with microRNA-181b in cerebral ischemic infarct of mice and hypoxia-induced neurons apoptosis. Methods: To address this question, we performed the experiments with in vivo middle cerebral artery occlusion (MCAO) mice model and in vitro oxygen-glucose deprivation (OGD)-cultured neuronal HT22 cell line. Relative expression of MEG3, miR-181b, and 12/15-LOX (lipoxygenase) mRNA was determined using quantitative RT-PCR. Western blot was used to evaluate 12/15-LOX protein expression. TUNEL assay was performed to assess cell apoptosis. Results: In both MCAO mice and OGD-cultured HT22 cell, ischemia, or hypoxia treatment results in a time-dependent increase in MEG3 and 12/15-LOX expression and decrease in miR-181b expression. Knockdown of MEG3 contributes to attenuation of hypoxia-induced apoptosis of HT22 cell. Also, expression level of MEG3 negatively correlated with miR-181b expression and positively correlated with 12/15-LOX expression. In contrary to MEG3, miR-181b overexpression attenuated hypoxia-induced HT22 cell apoptosis, as well as suppressed hypoxia-induced increase in 12/15-LOX expression. By luciferase reporter assay, we concluded that miR-181b directly binds to 12/15-LOX 3′-UTR, thereby negatively regulates 12/15-LOX expression. Conclusion: Our data suggested that long non-coding RNA MEG3 functions as a competing endogenous RNA for miR-181b to regulate 12/15-LOX expression in middle cerebral artery occlusion-induced ischemic infarct of brain nerve cells. PMID:27642276

  3. Aqueous extract of Cordyceps alleviates cerebral ischemia-induced short-term memory impairment in gerbils

    PubMed Central

    Lee, Sang-Hak; Ko, Il-Gyu; Kim, Sung-Eun; Hwang, Lakkyong; Jin, Jun-Jang; Choi, Hyun-Hee; Kim, Chang-Ju

    2016-01-01

    Cerebral ischemia is caused by reduced cerebral blood flow due to a transient or permanent cerebral artery occlusion. Ischemic injury in the brain leads to neuronal cell death, and eventually causes neurological impairments. Cordyceps, the name given to the fungi on insects, has abundant useful natural products with various biological activities. Cordyceps is known to have nephroprotective, hepatoprotective, anti-inflammatory, antioxidative, and antiapoptotic effects. We investigated the effects of Cordyceps on short-term memory, neuronal apoptosis, and cell proliferation in the hippocampal dentate gyrus following transient global ischemia in gerbils. For this study, a step-down avoidance test, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, immunohistochemistry for caspase-3 and 5-bromo-2′-de-oxyuridine, and western blot for Bax, Bcl-2, brain-derived neurotrophic factor (BDNF), and tyrosin kinase B were performed. In the present study, Cordyceps alleviated cerebral ischemia-induced short-term memory impairment. Cordyceps showed therapeutic effects through inhibiting cerebral ischemia-induced apoptosis in the hippocampus. Cordyceps suppressed cerebral ischemia-induced cell proliferation in the hippocampal dentate gyrus due to the reduced apoptotic neuronal cell death. Cordyceps treatment also enhanced BDNF and TrkB expressions in the hippocampus of ischemic gerbils. It can be suggested that Cordyceps overcomes cerebral ischemia-induced neuronal apoptosis, thus facilitates recovery following cerebral ischemia injury. PMID:27162767

  4. Aqueous extract of Cordyceps alleviates cerebral ischemia-induced short-term memory impairment in gerbils.

    PubMed

    Lee, Sang-Hak; Ko, Il-Gyu; Kim, Sung-Eun; Hwang, Lakkyong; Jin, Jun-Jang; Choi, Hyun-Hee; Kim, Chang-Ju

    2016-04-01

    Cerebral ischemia is caused by reduced cerebral blood flow due to a transient or permanent cerebral artery occlusion. Ischemic injury in the brain leads to neuronal cell death, and eventually causes neurological impairments. Cordyceps, the name given to the fungi on insects, has abundant useful natural products with various biological activities. Cordyceps is known to have nephroprotective, hepatoprotective, anti-inflammatory, antioxidative, and antiapoptotic effects. We investigated the effects of Cordyceps on short-term memory, neuronal apoptosis, and cell proliferation in the hippocampal dentate gyrus following transient global ischemia in gerbils. For this study, a step-down avoidance test, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, immunohistochemistry for caspase-3 and 5-bromo-2'-de-oxyuridine, and western blot for Bax, Bcl-2, brain-derived neurotrophic factor (BDNF), and tyrosin kinase B were performed. In the present study, Cordyceps alleviated cerebral ischemia-induced short-term memory impairment. Cordyceps showed therapeutic effects through inhibiting cerebral ischemia-induced apoptosis in the hippocampus. Cordyceps suppressed cerebral ischemia-induced cell proliferation in the hippocampal dentate gyrus due to the reduced apoptotic neuronal cell death. Cordyceps treatment also enhanced BDNF and TrkB expressions in the hippocampus of ischemic gerbils. It can be suggested that Cordyceps overcomes cerebral ischemia-induced neuronal apoptosis, thus facilitates recovery following cerebral ischemia injury.

  5. Mass-spectrometric characterization of phospholipids and their primary peroxidation products in rat cortical neurons during staurosporine-induced apoptosis.

    PubMed

    Tyurin, Vladimir A; Tyurina, Yulia Y; Feng, Weihong; Mnuskin, Alexandra; Jiang, Jianfei; Tang, Minke; Zhang, Xiaojing; Zhao, Qing; Kochanek, Patrick M; Clark, Robert S B; Bayir, Hülya; Kagan, Valerian E

    2008-12-01

    The molecular diversity of phospholipids is essential for their structural and signaling functions in cell membranes. In the current work, we present, the results of mass spectrometric characterization of individual molecular species in major classes of phospholipids -- phosphatidylcholine (PtdCho), phosphatidylethanolamine (PtdEtn), phosphatidylserine (PtdSer), phosphatidylinositol (PtdIns), sphingomyelin (CerPCho), and cardiolipin (Ptd(2)Gro) -- and their oxidation products during apoptosis induced in neurons by staurosporine (STS). The diversity of molecular species of phospholipids in rat cortical neurons followed the order Ptd(2)Gro > PtdEtn > PtdCho > PtdSer > PtdIns > CerPCho. The number of polyunsaturated oxidizable species decreased in the order Ptd(2)Gro > PtdEtn > PtdCho > PtdSer > PtdIns > CerPCho. Thus a relatively minor class of phospholipids, Ptd(2)Gro, was represented in cortical neurons by the greatest variety of both total and peroxidizable molecular species. Quantitative fluorescence HPLC analysis employed to assess the oxidation of different classes of phospholipids in neuronal cells during intrinsic apoptosis induced by STS revealed that three anionic phospholipids -- Ptd(2)Gro > PtdSer > PtdIns -- underwent robust oxidation. No significant oxidation in the most dominant phospholipid classes -- PtdCho and PtdEtn -- was detected. MS-studies revealed the presence of hydroxy-, hydroperoxy- as well as hydroxy-/hydroperoxy-species of Ptd(2)Gro, PtdSer, and PtdIns. Experiments in model systems where total cortex Ptd(2)Gro and PtdSer fractions were incubated in the presence of cytochrome c (cyt c) and H(2)O(2), confirmed that molecular identities of the products formed were similar to the ones generated during STS-induced neuronal apoptosis. The temporal sequence of biomarkers of STS-induced apoptosis and phospholipid peroxidation combined with recently demonstrated redox catalytic properties of cyt c realized through its interactions with Ptd(2)Gro

  6. Loss of GCN5 leads to increased neuronal apoptosis by upregulating E2F1- and Egr-1-dependent BH3-only protein Bim

    PubMed Central

    Wu, Yanna; Ma, Shanshan; Xia, Yong; Lu, Yangpeng; Xiao, Shiyin; Cao, Yali; Zhuang, Sidian; Tan, Xiangpeng; Fu, Qiang; Xie, Longchang; Li, Zhiming; Yuan, Zhongmin

    2017-01-01

    Cellular acetylation homeostasis is a kinetic balance precisely controlled by histone acetyl-transferase (HAT) and histone deacetylase (HDAC) activities. The loss of the counterbalancing function of basal HAT activity alters the precious HAT:HDAC balance towards enhanced histone deacetylation, resulting in a loss of acetylation homeostasis, which is closely associated with neuronal apoptosis. However, the critical HAT member whose activity loss contributes to neuronal apoptosis remains to be identified. In this study, we found that inactivation of GCN5 by either pharmacological inhibitors, such as CPTH2 and MB-3, or by inactivation with siRNAs leads to a typical apoptosis in cultured cerebellar granule neurons. Mechanistically, the BH3-only protein Bim is transcriptionally upregulated by activated Egr-1 and E2F1 and mediates apoptosis following GCN5 inhibition. Furthermore, in the activity withdrawal- or glutamate-evoked neuronal apoptosis models, GCN5 loses its activity, in contrast to Bim induction. Adenovirus-mediated overexpression of GCN5 suppresses Bim induction and apoptosis. Interestingly, the loss of GCN5 activity and the induction of Egr-1, E2F1 and Bim are involved in the early brain injury (EBI) following subarachnoid haemorrhage (SAH) in rats. HDAC inhibition not only significantly rescues Bim expression and apoptosis induced by either potassium deprivation or GCN5 inactivation but also ameliorates these events and EBI in SAH rats. Taken together, our results highlight a new mechanism by which the loss of GCN5 activity promotes neuronal apoptosis through the transcriptional upregulation of Bim, which is probably a critical event in triggering neuronal death when cellular acetylation homeostasis is impaired. PMID:28125090

  7. Loss of GCN5 leads to increased neuronal apoptosis by upregulating E2F1- and Egr-1-dependent BH3-only protein Bim.

    PubMed

    Wu, Yanna; Ma, Shanshan; Xia, Yong; Lu, Yangpeng; Xiao, Shiyin; Cao, Yali; Zhuang, Sidian; Tan, Xiangpeng; Fu, Qiang; Xie, Longchang; Li, Zhiming; Yuan, Zhongmin

    2017-01-26

    Cellular acetylation homeostasis is a kinetic balance precisely controlled by histone acetyl-transferase (HAT) and histone deacetylase (HDAC) activities. The loss of the counterbalancing function of basal HAT activity alters the precious HAT:HDAC balance towards enhanced histone deacetylation, resulting in a loss of acetylation homeostasis, which is closely associated with neuronal apoptosis. However, the critical HAT member whose activity loss contributes to neuronal apoptosis remains to be identified. In this study, we found that inactivation of GCN5 by either pharmacological inhibitors, such as CPTH2 and MB-3, or by inactivation with siRNAs leads to a typical apoptosis in cultured cerebellar granule neurons. Mechanistically, the BH3-only protein Bim is transcriptionally upregulated by activated Egr-1 and E2F1 and mediates apoptosis following GCN5 inhibition. Furthermore, in the activity withdrawal- or glutamate-evoked neuronal apoptosis models, GCN5 loses its activity, in contrast to Bim induction. Adenovirus-mediated overexpression of GCN5 suppresses Bim induction and apoptosis. Interestingly, the loss of GCN5 activity and the induction of Egr-1, E2F1 and Bim are involved in the early brain injury (EBI) following subarachnoid haemorrhage (SAH) in rats. HDAC inhibition not only significantly rescues Bim expression and apoptosis induced by either potassium deprivation or GCN5 inactivation but also ameliorates these events and EBI in SAH rats. Taken together, our results highlight a new mechanism by which the loss of GCN5 activity promotes neuronal apoptosis through the transcriptional upregulation of Bim, which is probably a critical event in triggering neuronal death when cellular acetylation homeostasis is impaired.

  8. Protein misfolding cyclic amplification induces the conversion of recombinant prion protein to PrP oligomers causing neuronal apoptosis.

    PubMed

    Yuan, Zhen; Yang, Lifeng; Chen, Baian; Zhu, Ting; Hassan, Mohammad Farooque; Yin, Xiaomin; Zhou, Xiangmei; Zhao, Deming

    2015-06-01

    The formation of neurotoxic prion protein (PrP) oligomers is thought to be a key step in the development of prion diseases. Recently, it was determined that the sonication and shaking of recombinant PrP can convert PrP monomers into β-state oligomers. Herein, we demonstrate that β-state oligomeric PrP can be generated through protein misfolding cyclic amplification from recombinant full-length hamster, human, rabbit, and mutated rabbit PrP, and that these oligomers can be used for subsequent research into the mechanisms of PrP-induced neurotoxicity. We have characterized protein misfolding cyclic amplification-induced monomer-to-oligomer conversion of PrP from three species using western blotting, circular dichroism, size-exclusion chromatography, and resistance to proteinase K (PK) digestion. We have further shown that all of the resulting β-oligomers are toxic to primary mouse cortical neurons independent of the presence of PrP(C) in the neurons, whereas the corresponding monomeric PrP were not toxic. In addition, we found that this toxicity is the result of oligomer-induced apoptosis via regulation of Bcl-2, Bax, and caspase-3 in both wild-type and PrP(-/-) cortical neurons. It is our hope that these results may contribute to our understanding of prion transformation within the brain. We found that β-state oligomeric PrPs can be generated through protein misfolding cyclic amplification (PMCA) from recombinant full-length hamster, human, rabbit, and mutated rabbit PrP. β-oligomers are toxic to primary mouse cortical neurons independent of the presence of PrP(C) in the neurons, while the corresponding monomeric PrPs were not toxic. This toxicity is the result of oligomers-induced apoptosis via regulation of Bcl-2, Bax, and caspase-3. These results may contribute to our understanding of prion transformation within the brain. © 2015 International Society for Neurochemistry.

  9. Coexistence of translocated cytochrome c and nitrated protein in neurons of the rat cerebral cortex after oxygen and glucose deprivation.

    PubMed

    Alonso, D; Encinas, J M; Uttenthal, L O; Boscá, L; Serrano, J; Fernández, A P; Castro-Blanco, S; Santacana, M; Bentura, M L; Richart, A; Fernández-Vizarra, P; Rodrigo, J

    2002-01-01

    Changes in the distribution of immunoreactive cytochrome c and protein nitration were studied in the rat cerebral cortex after oxygen and glucose deprivation by bright field, confocal and electron microscopy. In control cerebral cortex, nitrotyrosine immunoreactivity indicating protein nitration was found mostly in the neuronal nuclear region, with only a small amount distributed in the cytosol, whereas cytochrome c immunoreactivity was found at the inner membrane and in the intermembrane space of the mitochondria. During the recovery phase after oxygen and glucose deprivation, cytochrome c immunoreactivity was released from the intermembrane space of swollen mitochondria into the surrounding cytosol. The cytosol now also displayed nitrotyrosine immunoreactivity, which had diminished in the nuclear region. Both immunoreactivities were dispersed throughout the soma and processes of the cortical neurons. These changes were largely prevented by the administration of cyclosporin A, which inhibits both the mitochondrial permeability transition and the neuronal isoform of nitric oxide synthase while blocking the induction of the inducible isoform. Ischemia/reperfusion injury increases the production of nitric oxide, reactive oxygen species and intracellular factors that damage the mitochondria and liberate apoptotic factors. We suggest that translocation of cytochrome c from the mitochondria to the cytosol, which has been shown to precede the mitochondrial permeability transition, could result from peroxynitrite-mediated nitration. This phenomenon is attenuated by cyclosporin A administration, suggesting a neuroprotective role for this agent.

  10. DNA damage and activated caspase-3 expression in neurons and astrocytes: evidence for apoptosis in frontotemporal dementia.

    PubMed

    Su, J H; Nichol, K E; Sitch, T; Sheu, P; Chubb, C; Miller, B L; Tomaselli, K J; Kim, R C; Cotman, C W

    2000-05-01

    Frontotemporal dementia (FTD) is a neurodegenerative disease which affects mainly the frontal and anterior temporal cortex. It is associated with neuronal loss, gliosis, and microvacuolation of lamina I to III in these brain regions. In previous studies we have described neurons with DNA damage in the absence of tangle formation and suggested this may result in tangle-independent mechanisms of neurodegeneration in the AD brain. In the present study, we sought to examine DNA fragmentation and activated caspase-3 expression in FTD brain where tangle formation is largely absent. The results demonstrate that numerous nuclei were TdT positive in all FTD brains examined. Activated caspase-3 immunoreactivity was detected in both neurons and astrocytes and was elevated in FTD cases as compared to control cases. A subset of activated caspase-3-positive cells were also TdT positive. In addition, the cell bodies of a subset of astrocytes showed enlarged, irregular shapes, and vacuolation and their processes appeared fragmented. These degenerating astrocytes were positive for activated caspase-3 and colocalized with robust TdT-labeled nuclei. These findings suggest that a subset of astrocytes exhibit degeneration and that DNA damage and activated caspase-3 may contribute to neuronal cell death and astrocyte degeneration in the FTD brain. Our results suggest that apoptosis may be a mechanism of neuronal cell death in FTD as well as in AD (228).

  11. The role of mitochondria-mediated intrinsic death pathway in gingerdione derivative I6-induced neuronal apoptosis.

    PubMed

    Lin, Chia-Ho; Chen, Po-See; Kuo, Sheng-Chu; Huang, Li-Jiau; Gean, Po-Wu; Chiu, Ted-H

    2012-03-01

    Neuronal death induced by I6 displayed apoptotic characteristics but the precise mechanism has not been fully elucidated. In the present studies, I6 at 24 h after intraperitoneal administration significantly decreased the density of surviving neurons and increased caspase-3 activity in frontal cortex, suggesting that peripherally administered I6 may cross BBB to induce CNS toxicity. In rat embryonic primary cortical cells, I6-induced reduction of mitochondrial viability and neuronal apoptosis was inhibited by vitamin E. In addition, I6-induced reactive oxygen species (ROS) caused the disruption of mitochondria membrane potential (MMP), the release of cytochrome c, the activation of caspase-9 and caspase-3, and cleavage of poly(ADP-ribose) polymerase (PARP), resulting in activation of mitochondrial-mediated intrinsic death pathway. Pre-treatment with antioxidant vitamin E or N-acetylcysteine (NAC) completely abolished the I6-induced generation of ROS, loss of MMP, release of cytochrome c, activation of caspase-9 and caspase-3, and cleavage of PARP. Carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone (FCCP), a mitochondrial uncoupler, significantly reduced I6-induced neuronal death as well as caspase-3 activation and PARP cleavage. These results suggest that I6 induces neuronal death by promoting intracellular ROS production to cause a loss of MMP that result in release of cytochrome c and activation of mitochondria-mediated intrinsic death pathway.

  12. Alzheimer's presenilin 1 modulates sorting of APP and its carboxyl-terminal fragments in cerebral neurons in vivo.

    PubMed

    Gandy, Sam; Zhang, Yun-wu; Ikin, Annat; Schmidt, Stephen D; Bogush, Alexey; Levy, Efrat; Sheffield, Roxanne; Nixon, Ralph A; Liao, Francesca-Fang; Mathews, Paul M; Xu, Huaxi; Ehrlich, Michelle E

    2007-08-01

    Studies in continuously cultured cells have established that familial Alzheimer's disease (FAD) mutant presenilin 1 (PS1) delays exit of the amyloid precursor protein (APP) from the trans-Golgi network (TGN). Here we report the first description of PS1-regulated APP trafficking in cerebral neurons in culture and in vivo. Using neurons from transgenic mice or a cell-free APP transport vesicle biogenesis system derived from the TGN of those neurons, we demonstrated that knocking-in an FAD-associated mutant PS1 transgene was associated with delayed kinetics of APP arrival at the cell surface. Apparently, this delay was at least partially attributable to impaired exit of APP from the TGN, which was documented in the cell-free APP transport vesicle biogenesis assay. To extend the study to APP and carboxyl terminal fragment (CTF) trafficking to cerebral neurons in vivo, we performed subcellular fractionation of brains from APP transgenic mice, some of which carried a second transgene encoding an FAD-associated mutant form of PS1. The presence of the FAD mutant PS1 was associated with a slight shift in the subcellular localization of both holoAPP and APP CTFs toward iodixanol density gradient fractions that were enriched in a marker for the TGN. In a parallel set of experiments, we used an APP : furin chimeric protein strategy to test the effect of artificially forcing TGN concentration of an APP : furin chimera that could be a substrate for beta- and gamma-cleavage. This chimeric substrate generated excess Abeta42 when compared with wildtype APP. These data indicate that the presence of an FAD-associated mutant human PS1 transgene is associated with redistribution of the APP and APP CTFs in brain neurons toward TGN-enriched fractions. The chimera experiment suggests that TGN-enrichment of a beta-/gamma-secretase substrate may play an integral role in the action of mutant PS1 to elevate brain levels of Abeta42.

  13. Modeling local and cross-species neuron number variations in the cerebral cortex as arising from a common mechanism.

    PubMed

    Cahalane, Diarmuid J; Charvet, Christine J; Finlay, Barbara L

    2014-12-09

    A massive increase in the number of neurons in the cerebral cortex, driving its size to increase by five orders of magnitude, is a key feature of mammalian evolution. Not only are there systematic variations in cerebr