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ObjectiveTo explore the mechanism of Wenyang Jieyu prescription in regulating hippocampal neuron apoptosis and improving synaptic plasticity in the mouse model of depression induced by maternal separation combined with restraint stress. MethodThe mice on postnatal day 0 （PD0） were randomly assigned into a control group （n=10） and a modeling group （n=50）. Maternal separation combined with restraint stress was adopted to establish the mouse model of depression， and the modeled mice were randomized into model， Wenyang prescription， Jieyu prescription， Wenyang Jieyu prescription， and fluoxetine groups （n=10） on the weaning day （PD21）. From PD21 to PD111， the mice were fed with the diets mixed with corresponding medicines. The sucrose preference test， open field test， O-maze test， and novel object recognition test were then conducted to evaluate the depression， memory， and learning abilities of mice. Immunohistochemistry （IHC） was employed to measure the atomic absorbance （AA） of postsynaptic density protein 95 （PSD95） in the hippocampus. Terminal-deoxynucleoitidyl transferase-mediated nick-end labeling （TUNEL） was employed to detect the apoptosis of hippocampal neurons. Western blot was employed to determine the protein levels of brain-derived neurotrophic factor （BDNF）， phosphorylated tyrosine kinase receptor B/tyrosine kinase receptor B （p-TrkB/TrkB）， phosphorylated protein kinase B/protein kinase B （p-Akt/Akt）， phosphorylated mammalian target of rapamycin/mammalian target of rapamycin （p-mTOR/mTOR）， B-cell lymphoma-2 （Bcl-2）， Bcl-2-associated X （Bax）， cysteinyl aspartate-specific proteinase-3 （Caspase-3）， synaptophysin （Syn）， and PSD95. ResultCompared with the control group， the modeling decreased the sucrose preference rate， time spent in central zone within 5 min， total movement distance， time spent in the open arm， and cognition index （P<0.01）. Furthermore， it decreased the expression of PSD95， increased the neuron apoptosis in the hippocampus （P<0.01）， down-regulated the protein levels of BDNF， p-TrkB/TrkB， p-Akt/Akt， p-mTOR/mTOR， Bcl-2， PSD95， and Syn （P<0.01）， and up-regulated the protein levels of Bax and Caspase-3 （P<0.05） in the hippocampus. Compared with the model group， Wenyang Jieyu prescription and fluoxetine increased the sucrose preference rate， time spent in central zone within 5 min， total movement distance， time spent in the open arm， and cognition index （P<0.05， P<0.01）. Moreover， the drugs increased the expression of PSD95， reduced the neuron apoptosis （P<0.01）， up-regulated the protein levels of BDNF， p-TrkB/TrkB， p-Akt/Akt， p-mTOR/mTOR， Bcl-2， PSD95， and Syn （P<0.01）， and down-regulated the protein levels of Bax and Caspase-3 （P<0.01）. ConclusionWenyang Jieyu prescription outperformed Wenyang prescription and Jieyu prescription in the treatment of the depressive behavior induced by maternal separation combined with restraint stress in mice. It exerted the therapeutic effect by reducing the hippocampal neuron apoptosis and improving the synaptic plasticity via the BDNF/Akt/mTOR pathway.
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Recently p75 neurotrophin receptor (p75NTR) has been found to play a critical role in the pathology of neurodegen¬erative! diseases including Alzheimer's disease (AD) , Parkin¬son' s disease ( PI)), Huntington's disease ( HI)) , amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS).This arti¬cle reviews the research progress of p75NTR in regulating neuron apoptosis, axon degeneration and cognitive impairment, explo¬ring the application of p75NTR as a potential therapeutic target for the treatment of neurodegenerative diseases.
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Objective: To study the effect of isoflurane anesthesia on the hippocampal neuroapoptosis in the zincdeficient APP/PS1 transgenic mice, and to clarify its related mechanisms. Methods: The eight-month or ninemonth old APP/PS1 transgenic mice were randomly assigned to four groups (n=24): zinc adequate (ZA) group, the mice were given a standard diet for 2 months; zinc adequate + isoflurane (ZA+Iso) group, the mice were given a standard diet for 2 months then exposed to 1. 4% isoflurane for 2 h; zinc-deficient (ZD) group, the mice were given zinc deficient diet for 1 month; zinc deficient with isoflurane (ZD+Iso) group, the mice were given zinc deficient diet for 1 month and then exposed to 1. 4% isoflurane for 2 h. The hippocampus tissue of the mice were obtained 24 h after anesthesia. The immunofluorescence double staining was performed to measure the apoptotic rates of hippocampal neurons. The Western blotting method was used to detect the expression levels of Aβ and Cleaved caspase-3 and the ratio of Bax/Bcl-2. Results: Compared with ZA group, the apoptotic rate of neurons, the ratio of Bax/Bcl-2 and the expression level of Cleaved caspase-3 of the mice in ZA+Iso group were increased 6 h after isoflurane exposure (P0. 05). Compared with ZA group, the apoptotic rates of neurons, the ratios of Bax/Bcl-2, the expression levels of Aβ42 and Cleaved caspase-3 of the mice in ZD group and ZD+Iso group were increased 6 and 24 h after isoflurane exposure (P<0. 05 or P<0. 01). Compared with ZD group, the apoptotic rate of neurons, the expression levels of Aβ42, Bax/Bcl-2 and Cleaved caspase-3 and the ratio of Bax/Bcl-2 of the mice in ZD+Iso group were elevated significantly 6 and 24 h after isoflurane exposure (P<0. 05 or P<0. 01). Conclusion: 1.4% isoflurane exposure for 2 h can induce the transient elevation of hippocampal neuroapoptosis in the ten-month old APP/PS1 transgenic mice. 1.4% isoflurane exposure for 2 h can significantly aggravate the hippocampal neuroapoptosis in the zinc-deficient APP/PS1 transgenic mice, it is probably associated with the hippocampal Aβ aggregation, activation of Bax and Caspase-3 and inhibition of Bcl-2.
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The purpose of this study was to evaluate the roles of different housing environments in neurological function,cerebral metabolism,cerebral infarction and neuron apoptosis after focal cerebral ischemia.Twenty-eight Sprague-Dawley rats were divided into control group (CG) and cerebral ischemia group,and the latter was further divided into subgroups of different housing conditions:standard environment (SE) subgroup,individual living environment (IE) subgroup,and enriched environment (EE) subgroup.Focal cerebral ischemia was induced by the middle cerebral artery occlusion (MCAO).Beam walking test was used to quantify the changes of overall motor function.Cerebral infarction and cerebral metabolism were studied by in vivo magnetic resonance imaging and 1H-magnetic resonance spectra,respectively.Neuron necrosis and apoptosis were detected by hematoxylin-eosin and TUNEL staining methods,respectively.The results showed that performance on the beam-walk test was improved in EE subgroup when compared to SE subgroup and IE subgroup.Cerebral infarct volume in IE subgroup was significantly larger than that in SE subgroup (P＜0.05) and EE subgroup (P＜0.05) on day 14 after MCAO.NAA/Cr and Cho/Cr ratios were lower in MCAO groups under different housing conditions as compared to those in CG (P＜0.05).NAA/Cr ratio was lower in IE subgroup (P＜0.05) and higher in EE subgroup (P＜0.05) than that in SE subgroup.NAA/Cr ratio in EE was significantly higher than that in IE subgroup (P＜0.05).Cho/Cr ratio was decreased in MCAO groups as compared to that in CG (P＜0.05).A significant decrease in normal neurons in cerebral cortex was observed in MCAO groups as compared to CG (P＜0.05).The amount of normal neurons was less in IE subgroup (P＜0.05),and more in EE subgroup (P＜0.05) than that in SE subgroup after MCAO.The amount of normal neurons in EE subgroup was significantly more than that in IE subgroup after MCAO (P＜0.05).The ratio of TUNEL-positive neurons in EE was significantly lower than that in SE subgroup (P＜0.05) and IE subgroup (P＜0.05).Correlation analysis showed that the beam walking test was negatively correlated with NAA/Cr ratio (P＜0.05).Cerebral infarct volume was negatively correlated with both NAA/Cr ratio (P＜0.01) and Cho/Cr ratio (P＜0.01).The amount of normal cortical neurons was positively correlated with both NAA/Cr ratio (P＜0.01) and Cho/Cr ratio (P＜0.05).The TUNEL-positive neurons showed a negative correlation with both NAA/Cr ratio (P＜0.01) and Cho/Cr ratio (P＜0.01).This study goes further to show that EE may improve neurological functional deficit and cerebral metabolism,decrease cerebral infarct volume,neuron necrosis and apoptosis,while IE may aggravate brain damage after MCAO.
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The purpose of this study was to evaluate the roles of different housing environments in neurological function,cerebral metabolism,cerebral infarction and neuron apoptosis after focal cerebral ischemia.Twenty-eight Sprague-Dawley rats were divided into control group (CG) and cerebral ischemia group,and the latter was further divided into subgroups of different housing conditions:standard environment (SE) subgroup,individual living environment (IE) subgroup,and enriched environment (EE) subgroup.Focal cerebral ischemia was induced by the middle cerebral artery occlusion (MCAO).Beam walking test was used to quantify the changes of overall motor function.Cerebral infarction and cerebral metabolism were studied by in vivo magnetic resonance imaging and 1H-magnetic resonance spectra,respectively.Neuron necrosis and apoptosis were detected by hematoxylin-eosin and TUNEL staining methods,respectively.The results showed that performance on the beam-walk test was improved in EE subgroup when compared to SE subgroup and IE subgroup.Cerebral infarct volume in IE subgroup was significantly larger than that in SE subgroup (P＜0.05) and EE subgroup (P＜0.05) on day 14 after MCAO.NAA/Cr and Cho/Cr ratios were lower in MCAO groups under different housing conditions as compared to those in CG (P＜0.05).NAA/Cr ratio was lower in IE subgroup (P＜0.05) and higher in EE subgroup (P＜0.05) than that in SE subgroup.NAA/Cr ratio in EE was significantly higher than that in IE subgroup (P＜0.05).Cho/Cr ratio was decreased in MCAO groups as compared to that in CG (P＜0.05).A significant decrease in normal neurons in cerebral cortex was observed in MCAO groups as compared to CG (P＜0.05).The amount of normal neurons was less in IE subgroup (P＜0.05),and more in EE subgroup (P＜0.05) than that in SE subgroup after MCAO.The amount of normal neurons in EE subgroup was significantly more than that in IE subgroup after MCAO (P＜0.05).The ratio of TUNEL-positive neurons in EE was significantly lower than that in SE subgroup (P＜0.05) and IE subgroup (P＜0.05).Correlation analysis showed that the beam walking test was negatively correlated with NAA/Cr ratio (P＜0.05).Cerebral infarct volume was negatively correlated with both NAA/Cr ratio (P＜0.01) and Cho/Cr ratio (P＜0.01).The amount of normal cortical neurons was positively correlated with both NAA/Cr ratio (P＜0.01) and Cho/Cr ratio (P＜0.05).The TUNEL-positive neurons showed a negative correlation with both NAA/Cr ratio (P＜0.01) and Cho/Cr ratio (P＜0.01).This study goes further to show that EE may improve neurological functional deficit and cerebral metabolism,decrease cerebral infarct volume,neuron necrosis and apoptosis,while IE may aggravate brain damage after MCAO.
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Objective:To study the effect of isoflurane anesthesia on the hippocampal neuroapoptosis in the zincdeficient APP/PS1 transgenic mice,and to clarify its related mechanisms.Methods:The eight-month or ninemonth old APP/PS1 transgenic mice were randomly assigned to four groups (n=24):zinc adequate (ZA) group,the mice were given a standard diet for 2 months;zinc adequate+ isoflurane (ZA+ Iso) group,the mice were given a standard diet for 2 months then exposed to 1.4％ isoflurane for 2 h;zinc-deficient (ZD) group,the mice were given zinc deficient diet for 1 month;zinc deficient with isoflurane (ZD+Iso) group,the mice were given zinc deficient diet for 1 month and then exposed to 1.4％ isoflurane for 2 h.The hippocampus tissue of the mice were obtained 24 h after anesthesia.The immunofluorescence double staining was performed to measure the apoptotic rates of hippocampal neurons.The Western blotting method was used to detect the expression levels of Aβ and Cleaved caspase-3 and the ratio of Bax/Bcl-2.Results:Compared with ZA group,the apoptotic rate of neurons,the ratio of Bax/Bcl-2 and the expression level of Cleaved caspase-3 of the mice in ZA+Iso group were increased 6 h after isoflurane exposure (P＜0.05 or P＜0.01);but no differences were found in the apoptotic rate of neurons and the expression levels of total Aβ,Aβ40 and Aβ42 24 h after isoflurane exposure (P＞0.05).Compared with ZA group,the apoptotic rates of neurons,the ratios of Bax/Bcl-2,the expression levels of Aβ42 and Cleaved caspase-3 of the mice in ZD group and ZD+ Iso group were increased 6 and 24 h after isoflurane exposure (P＜0.05or P＜0.01).Compared with ZD group,the apoptotic rate of neurons,the expression levels of Aβ42,Bax/Bcl-2and Cleaved caspase-3 and the ratio of Bax/Bcl-2 of the mice in ZD+Iso group were elevated significantly 6 and 24 h after isoflurane exposure (P＜0.05 or P＜0.01).Conclusion:1.4％ isoflurane exposure for 2 h can induce the transient elevation of hippocampal neuroapoptosis in the ten-month old APP/PS1 transgenic mice.1.4 ％ isoflurane exposure for 2 h can significantly aggravate the hippocampal neuroapoptosis in the zinc-deficient APP/PS1 transgenic mice,it is probably associated with the hippocampal Aβ aggregation,activation of Bax and Caspase-3 and inhibition of Bcl-2.
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Objective To explore the effect of the retinoic acid (RA) on the apoptosis of neurons caused by hypoxic ischemic brain damage (HIBD).Methods Seventy-two newborn Sprague-Dawley rats were randomly divided into an RA deficiency (RAD) group,an RA normal (RAN) group and a control group,each of 24.The HIBD model was established in the RAD and RAN groups using Rice's method.The left common carotid artery was exposed,ligated and cut,inducing hypoxia.In the control group the left common carotid artery was exposed without any other treatment.Three and 7 days after the operation,neuron apoptosis in the brain tissue was evaluated using TUNEL staining.The degree of HIBD was quantified using modified neurological severity scores (mNSS) 7,14,21 and 28 days after the operation.Primary neurons were cultured in vitro,and oxygen glucose deprivation (OGD) was induced,then control,OGD and RA+ OGD groups were formed.The gene transcription and the protein activity of retinoic acid receptor alpha (RARcα),GDNF (glial cell line-derived neurotrophic factor) and Caspase-8 were examined with polymerase chain reactions (PCR) and Western blotting.The RA+OGD group was exposed to RA and SiRNA adenovirus,and divided into a silenced group and a negative transfection group according to the infection.Results The average mNSS of the RAD group was significantly higher than that of the RAN group.TUNEL staining showed that the apoptotic cells in the cortex increased from day 3 to 7 after the operation,but significantly more in the RAD group than in the RAN group.The gene transcription and protein activity of RARα and GDNF in the RA+OGD group were significantly higher than in the OGD group,and those of Caspase-8 were significantly lower.The gene transcription and protein activity of RARα and GDNF in the silenced group were significantly lower than in the negative transfection group,while those of Caspase-8 were just the opposite.Conclusion RA can inhibit the apoptosis of primary neurons after HIBD by up-regulating the expression of GDNF and down-regulating that of Caspase-8 via RARα.
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Potassium 2-(1-hydroxypentyl)-benzoate (d,l-PHPB), a new drug candidate for ischemic stroke at the phase II clinic trial, has been shown to protect neurons by inhibiting oxidative injury and reducing neuron apoptosis in previous studies. But the mechanisms of d,l-PHPB remain to be studied. In this study, a neuron-astrocytes co-culture system was used to elucidate the roles of astrocytes in neuroprotection of d,l-PHPB under oxygen-glucose deprivation/reoxygenation (OGD/R) condition. Our data showed that d,l-PHPB reduced neuronal apoptosis in mono-culture system and this effect was enhanced in neuron-astrocyte co-culture system under the OGD/R condition. Meanwhile, d,l-PHPB obviously increased the levels of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), which were mainly secreted from astrocytes, in the co-culture system after OGD/R. The PI3K/AKT and ERK signaling pathways as well as the p-TRKA/B receptors were involved in the process. In addition, the levels of TNF-and IL-1secreted from astrocytes after OGD/R were markedly reduced after d,l-PHPB treatment, which was mainly due to the suppression of phosphorylated p38. In conclusion, the present study demonstrates that the neuroprotective effects of d,l-PHPB were improved by astrocytes, mainly mediated by increasing the release of BDNF/NGF and attenuating inflammatory cytokines.
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Studies have shown that acetylcholinesterase inhibitors donepezil and galantamine have effects of reducing neuronal damage caused by glucose deprivation and reducing the cerebral infarction volume of cerebral ischemic animals, but their effects may not be entirely dependent on its inhibition of cholinesterase activity. In order to study the effects of donepezil and galantamine on neuronal injury of cerebral ischemia, the rat neuron-astrocyte co-culture model was successfully established in this study. In this model, we studied the effects of donepezil and galantamine on neuron apoptosis induced by oxygen-glucose deprivation/reoxygenation (OGD/R) and investigated the mechanism. The results showed that donepezil and galantamine significantly reduced the neuron apoptosis, and promoted the synthesis and secretion of BDNF and NGF in astrocytes in the co-culture system. Donepezil and galantamine activated the PI3K/Akt pathway and ERK pathway, and promoted the phosphorylation of the nuclear transcription factor CREB. These results suggest that donepezil and galantamine exhibit protective effects on neuronal damage induced by OGD/R. The mechanism may be related to activation of PI3K/Akt pathway and ERK pathway in astrocytes and promote phosphorylation of CREB, which lead to the synthesis and secretion of BDNF and NGF from astrocytes.
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@#Objective To investigate the effect of Rhodiola Rosae P. E on the expression of c-Fos and the apoptosis of neuronal in rat brain after ischemia/reperfusion (I/R) injury. Methods 120 Wistar rats were divided into sham group, model group and intervention group,subgrouped as 3 h, 6 h, 12 h, 24 h, and 48 h. The model and intervention groups underwent middle cerebral artery occlusion, and the latter accepted Rhodiola 0.672 g/kg daily for 15 d. They were assessed with Longa's score. The expression of c-Fos and apoptosis of neuronal were measured with immunohistochemistry and TUNEL. Results The expression of c-Fos in the ischemic area increased after cerebral ischemia/reperfusion (P<0.01), peaking at 24 h after injury, and decreased in the intervention group (P<0.01), with the decrease of neuron apoptosis and Longa's score (P<0.01). Conclusion Rhodiola protects the brain tissue against ischemia/reperfusion injury by inhibiting the expression of c-Fos and apoptosis in rats.
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Objective To investigate the role of SCF on neuronal apoptosis induced by diabetes and its possible mechanism.Methods Twenty-seven male C57 mice were randomly divided into control group,diabetes group,and diabe-tes plus stem cell factor(SCF)group.The diabetic mice were induced by streptozotocin.TUNEL staining was used to assess neuronal apoptosis and western blot were used to detect the protein level of BCL-2,BAX,CASPASE 3 and P-ERK/ERK.Results Compared with the controls,the number of apoptotic neuron death and the protein levels of active CASPASE 3 were significantly increased in the cortex of diabetic mice.Treatment with SCF significantly reduced apoptotic neuron death and attenuated the increased in protein levels of active CASPASE 3 in the cortex of diabetic mice.The levels of BCL-2 and BAX were significantly increased in the diabetic animals compared to the controls.Treatment with SCF could significantly attenuated the increase in the expression of BAX but could not affect the level of BCL-2 in the cortex of diabetic mice.P-ERK was significantly decreased in the diabete group but not in dibete plus SCF group.Conclusions SCF can protect a-gainst diabete-induced apoptotic neuron death through increasing the phosphorylation of ERK and influencing the expression of BCL-2/BAX.
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Objective To explore the inhibitory effects of Zibu Piyin Recipe(ZBPYR)serum on neuron apoptosis induced by tunieamyein(Tm,5 μg/ml)and its mechamsm in vitro by using sero-pharmacological method.Method Totally 12 healthy adult male SD rats(220～250 g)(SPF)were divided randomly into control group and ZBPYR group,6 in each group,then the blank and ZBPYR serum were prepared.The mouse.neuroblastoma cell line Neum2a cells were treated with Tunicamycin(Tin,an inhibitor of N-glycoslytion)to establish the endoplasmic reticulum(ER)stress model.The cells treated by ZBPYR aerum of different concentrations were interventional groups,and the cells treated by blank serum were control group.The viability of Neuro2a cells was meusurcdd by MTT assay.Flow cytometry wus applied to observe the apoptosis of Neuro2a cells.Western blotting was utilized to detect the protein expressions of two molecules,ER molecular chaperone-ucose regulated protein 78(CRP78)and transcriptional factor CCAAT/enhancer-binding protein-homologous protein(CHOP).The results were analyzed by sNK-q test.Results Compared to Tm group(cell viability 0.1673±0.0213,apoptotic rate 62.7050±1.4056),The cell viability of interventional groups(5%0.5295±0.0373,10%0.5843±0.0428,15%0.6274±0.0324)increased significantly(P<0.05);and the apoptotic rate(5%47.8733±2.8166,10%46.3366±1.2748,15%39.8833±1.0524)reduced significantly(P<0.05).The protein expressions of GRP 78(5%2.1228±0.2251,10%1.3293±0.9443,15%;15%0.0931±0.1168)and CHOP(5%1.1776±0.2927,10%0.7290±0.1708,15%0.6577±0.1883)of interventional groups reduced significantly compared with Tm group(GRP78 2.9149±0.5355;CHOP 1.6611±0.2913)P<0.05.Condusions ZBPYR serurn could increase the cell viability of Neuro2a cells treated with Tm and inhibit cell apoptosis.Thereby it may have neuroprotective effects,and the mechanism may be associated with the inhibition of ER stress and apoptosis pathway.
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@#Objective To investigate the possible protective effect of neurotropin on the corresponding spinal cord motoneuron after sciatic nerve injury early in rats.Methods 108 male Sprague Dawley rats were divided randomly into Groups A,B and C with 36 animals in each group,and all animals were cut both side of sciatic nerve,instantly make the operation of end-to-end anastomose of epineurium for abscised sciatic nerve.Group A was control group.Group B was treated with neurotropin and Group C was treated with normal saline after operation.The rats were sacrificed on 1st d,4th d,9th d,14th d,21st d and 28th d after operation.The corresponding spinal cord segments(L4～L6)were gotten to make Bcl-2 and Bax immunohistochemical staining and TUNEL staining.Results The values of Bcl-2/Bax on 9th d,14th d and 21st d after operation of Group B were different from that of Group A and Group C.The number of positive cells stained by TUNEL staining on 9th d was significantly different among Group A,Group B and Group C(v<0.05).The expression of positive TUNEL staining cells reached a peak on 14th d after operation,the number of Group B was less than that of Group A and Group C.Conclusion After instantly make the operation of end-to-end anastomose of epineurium for abscised sciatic nerve,neurotropin can protect the spinal cord motoneurons to avoid apoptosis excessively in some extent.
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Objective: To observe the synergetic effect of folic acid and genistein on apoptosis in the early stage of neuron and its possible mechanism. Methods: Cyclophosphamide was added to primary cultured neurons to induce apoptosis. Three different dosages of folic acid and genistein were used to inhibit apoptosis. The results were observed by flow cytometry and scanning electron microscopy (SEM). Results: 1.Folic acid and genistein might play a role in early stages of neuron apoptosis, and the synergetic effect was demonstrated when folic acid and genistein were administered together. 2. The membrane changes in early stages of neuron apoptosis observed by scanning electron microscope were also in agreement with the flow cytometry data. Conclusion: Genistein might reinforce the protective effect of folic acid on neural tube defects by restraining the apoptosis of the early stage of neuron.