Effects of Ginsenoside Rgl on nuclear factor-kappa B activity in beta amyloid protein-treated neural cells

BACKGROUND： Modern pharmacological studies have shown that Ginsenoside Rgl is one of the active components of ginseng that promote intelligence in the nervous system. Ginsenoside Rgl can improve memory and learning in mouse models of β-amyloid protein （Aβ）-induced dementia. OBJECTIVE： To investigate whether effects of Ginsenoside Rgl against Aβ are associated with activity of nuclear factor-kappa B （NF-κB）. DESIGN, TIME AND SETTING： The randomized performed at the DME Center, Institute of Clinica controlled, cell biological experiment was Pharmacology, Guangzhou University of Chinese Medicine, China from July 2005 to May 2006. MATERIALS： Beta-amyloid fragment 25-35 （Aβ25-35） was supplied by the Neural Biochemical Laboratory, Xuanwu Hospital, Capital Medical University, China. Ginsenoside Rgl was obtained from National Institute for the Control of Pharmaceutical and Biological Products, China. Rabbit anti-rat NF-κB p65 antibody was purchased from Santa Cruz Biotechnology, USA. METHODS： Hippocampal neurons and cortical astrocytes of neonatal Sprague Dawley rats were harvested and treated with various concentrations （0, 5, 10, 20, and 40 μmol/L） of Aβ for 6, 12, and 24 hours to establish cellular models of Alzheimer＇s disease. Cellular models were pretreated with various concentrations of Ginsenoside Rgl （1,2, 4, 8, and 16 μmol/L）. According to cell morphology and activity, the following conditions were selected： 40 μmol/L Aβ for 24 hours, as well as 2, 4, and 8 μmol/L Ginsenoside Rg1. NF-κB activity was observed using immunofluorescence and cytochemical staining. MAIN OUTCOME MEASURES： Morphology and viability of hippocampal neurons and cortical astrocytes, and activities of NF-κB were measured. RESULTS： Hippocampal neuron activity was significantly greater in the normal and 2 and 4 μmol/L Ginsenoside Rgl groups compared with the model group （P 〈 0.05）. Astrocyte activity was significantly greater in the normal, 1,2, 4, 8, and 16 μmol/L Ginsenoside Rgl groups compared with the model group （P 〈 0.05）. NF-κB activity of hippocampal neurons was significantly greater in the normal, 2, 4, and 8 μmol/L Ginsenoside Rgl groups compared with the model group （P 〈 0.01）. NF-κB activity of astrocytes was significantly less in the normal, 2, 4, and 8 μmol/L Ginsenoside Rgl groups compared with the model group （P 〈 0.01 or P 〈 0.05）. No significant difference in NF-κB activity was determined between the 2 μmol/L Ginsenoside Rgl and normal groups （P 〉 0.05）. CONCLUSION： Ginsenoside Rgl protected neural cells by upregulating NF-κB activity in neurons and downregulating NF-κB activity in astrocytes. Ginsenoside Rgl （2 μmol/L） maintained cell activity and NF-κB activity at normal levels.     

左旋丁苯酞对Aβ1-42诱导原代培养大鼠基底前脑和海马神经元Caspase-3及NF-κB表达的影响

BACKGROUND： L-3-n-butylphthalide （L-NBP） can inhibit phosphorylation of tau protein and reduce the neurotoxicity of beta-amyloid peptide 1-42 （Aβ1-42）. OBJECTIVE： To observe the neuroprotective effects of L-NBP on caspase-3 and nuclear factor kappa-B （NF- K B） expression in a rat model of Alzheimer＇s disease. DESIGN, TIME AND SETTING： A cell experiment was performed at the Central Laboratory of Provincial Hospital affiliated to Shandong University between January 2008 and August 2008. MATERIALS： L-NBP （purity 〉 98%） was provided by Shijiazhuang Pharma Group NBP Pharmaceutical Company Limited. Aβ1-42, 3-[4,5-dimethylthiazolo-2]-2,5 iphenyltetrazolium bromide （MTT）, and rabbit anti-Caspase-3 polyclonal antibody were provided by Cell Signaling, USA; goat anti-choactase and rabbit anti-NF- kB antibodies were provided by Santa Cruz, USA. METHODS： Primary cultures were generated from rat basal forebrain and hippocampal neurons at 17 or 19 days of gestation. The cells were assigned into five groups： the control group, the Aβ1-42 group （2 μmol/L）, the Aβ1-42 ＋ 0.1 μmol/L L-NBP group, the Aβ1-42 ＋ 1 μ mol/L L-NBP group, and the Aβ1-42 ＋ 10μmol/L L-NBP group. The neurons were treated with Aβ1-42 （2 μmol/L） alone or in combination with L-NBP （0.1, 1, 10 μmol/L） for 48 hours. Cells in the control group were incubated in PBS. MAIN OUTCOME MEASURES： Morphologic changes were evaluated using inverted microscopy, viability using the M-I-I- method, and the changes in caspase-3 and NF- k B expression using Western blot. RESULTS： Induction with Aβ1-42 for 48 hours caused cell death and soma atrophy, and increased caspase-3 and NF- K B expression （P 〈 0.05）. L-NBP blocked these changes in cell morphology, decreased caspase-3 and NF- k B expression （P 〈 0.05）, and improved cell viability, especially at the high dose （P 〈 0.05）. CONCLUSION： AI3~-42 is toxic to basal forebrain and hippocampal primary neurons; L-NBP protects against this toxicity and inhibits the induction of caspase-3 and NF- K B expression.     

Propofol increases in vitro proliferation of cultured rat hippocampal precursor cells inhibited by corticosterone

BACKGROUND： Previous studies have shown that propofol enhances proliferation of cultured hippocampal precursor cells in vitro and increases proliferation of cultured hippocampal precursor cells inhibited by corticosterone. Because gamma-aminobutyric acid A （GABA-A） receptor is the functional target for propofol, the proliferative effects of propofol are thought to take place through GABA-A receptor. OBJECTIVE： To determine whether propofol enhances proliferation of rat hippocampal precursor cells inhibited by corticosterone by upregulating expression of GABA-A receptor. DESIGN, TIME AND SETTING： A comparative, observational, in vitro experiment was performed at the Beijing Institute of Pharmacology and Toxicology from April 2005 to April 2006. MATERIALS： Propofol was purchased from AstraZeneca, italy; corticosterone was purchased from Sigma, USA; bicuculline was purchased from Alexis, Switzerland. METHODS： Hippocampal precursor cells were isolated from newborn Wistar rats and cultured in vitro. The second passage of precursor cells was grouped according to the various drugs added to the culture medium： 0.5 μmol/L propofol; 2.5 pmol/L propofol; 100 μmol/L corticosterone; 10 μmol/L bicuculline; 100 μmol/L corticosterone and 0.5 μmol/L propofol; 100 μmol/L corticosterone and 2.5 μmol/L propofol; 100 μmol/L corticosterone, 10 μmol/L bicuculline, and 0.5 μmol/L propofol; 100 μmol/L corticosterone, 10 μmol/L bicuculline, and 2.5 μmol/L propofol; 100 μmol/L corticosterone and 10 pmol/L bicuculline. The cells were cultured for 24 hours with medium containing the respective concentration of drug. The control group consisted of precursor cells absent of drug treatment. MAIN OUTCOME MEASURES： The MTT and ^3H-TdR incorporation assays were used to detect proliferative effects of propofol and bicuculline on cultured rat hippocampal precursor cells inhibited by corticosterone. Immunocytochemistry was used to detect GABA-A receptor expression. Enzyme-linked irnmunosorbent assay was used to quantify GABA-A receptor expression. RESULTS： Propofol, at a concentration of 0.5 and 2.5 μmol/L, increased proliferation of cultured rat hippocampal precursor cells inhibited by corticosterone, while bicuculline antagonized the effects of propofol （P 〈 0.05 or P 〈 0.01 ）. Corticosterone （100μmol/L） decreased expression of GABA-A receptor in the hippocampal precursor cells （P〈 0.05）, and GABA-A receptor expression was upregulated when propofol （2.5μmol/L） was added to the culture medium （P〈 0.05）. CONCLUSION： Low concentrations of propofol increased expression of GABA-A receptor. These results suggest that GABA-A receptor is involved in increased proliferation of cortisone-inhibited rat hippocampal precursor cells in vitro.     

Dose-dependent effects of lead on cell-cycle arrest, DNA damage, and cyclin D1 expression in primary cultured rat hippocampal neurons

BACKGROUND: Previous studies have suggested that the hippocampus is one of the neurotoxic target sites for lead. However, the molecular mechanisms of action, including the effect of lead on cell-cycle arrest, remain poorly understood.OBJECTIVE: To investigate the effects of different lead concentrations on cell-cycle arrest, DNA damage, and cyclin D1 expression in primary cultured rat hippocampal neurons.DESIGN, TIME AND SETTING: A randomized, controlled, in vitro experiment was performed at the China Medical University between July 2008 and May 2009.MATERIALS: Antibodies specific to cyclin D1 and actin were synthesized and purified by Santa Cruz Biotechnology, USA. FACStar flow cytometer was purchased from Becton Dickinson, San Jose, California, USA.METHODS: Wistar rat hippocampal neurons were primary cultured for 7 days. Neurons in the control group were treated with 0.01 mol/L phosphate buffered saline. Neurons in the 0.2,1.0, and 10 umol/L lead acetate groups were subjected to 0.2,1.0, and 10 μmol/L lead acetate. Subsequently,hippocampal neurons in each group were cultured for 24 hours.MAIN OUTCOME MEASURES: The effects of lead on cell cycle were measured by flow cytometry,DNA damage was measured using the comet assay, and cyclin D1 expression was measured using Western blot analysis.RESULTS: Treatment of hippocampal neurons with 0.2 μmol/L lead acetate did not significantly alter cell cycle phase distribution, i.e., sub-G_1, S, G0/G1, G_2/M, whereas treatment with 1.0 and 10 μmol/L lead acetate significantly increased the percentage of S and sub-G_1 phase cells (P< 0.05). Olive tail moment in all lead-treated groups and the percentage of DNA in the tail in 1.0 μmol/L and 10 μmol/L lead acetate groups were significantly greater compared with the control group (P < 0.05). In addition, the percentage of tail DNA was greater in the 0.2 μmol/L lead acetate group compared with the control group (P>0.05). Following incubation with 0.2,1.0, and 10 μmol/L lead acetate for 24 hours, cyclin D1 expression gradually decreased with exposure to increasing lead acetate concentrations (1.0-10 μmol/L).CONCLUSION: Lead exposure to primary cultured rat hippocampal neurons resulted in dose-dependently disturbed cellular homeostasis, including DNA damage, reduced cyclin D1 expression, and stagnation of cell-cycle progression.     

Underlying mechanism of protection from hypoxic injury seen with n-butanol extract of Potentilla anserine L. in hippocampal neurons

The alcohol and n-butanol extract of Potentilla anserine L. significantly protects myocardium from acute ischemic injury. However, its effects on rat hippocampal neurons and the mechanism of protection remain unclear. In this study, primary cultured hippocampal neurons from neonatal rats were incubated in 95% N2 and 5% CO2 for 4 hours. Results indicated that hypoxic injury decreased the viability of neurons, increased the expression levels of caspase-9 and caspase-3 mRNA, as well as cytochrome c, Caspase-9, and Caspase-3 protein. Pretreatment with 0.25, 0.062 5, 0.015 6 mg/mL n-butanol extract of Potentilla anserine L. led to a significant increase in cell viability. Expression levels of caspase-9 and caspase-3 mRNA, as well as cytochrome c, Caspase-9, and Caspase-3 protein, were attenuated. The neuroprotective effect of n-butanol extract of Potentilla anserine L. was equivalent to tanshinone IIA. Our data suggest that the n-butanol extract of Potentilla anserine L. could protect primary hippocampal neurons from hypoxic injury by deactivating mitochondrial cell death.     

蝙蝠葛酚性碱与褪黑素对缺血再灌注损伤神经元的作用比较

BACKGROUND： Recent studies have demonstrated that phenolic alkaloids from Menispermum dauricum （PAMD） can protect the heart and brain from ischemia/reperfusion injury, and promote neuron survival by inhibiting neuronal Bax and upregulating Bcl-2 expression following ischemia/reperfusion.
OBJECTIVE： To investigate the neuroprotective effects of PAMD versus exogenous melatonin against ischemia/reperfusion injury.
DESIGN, TIME AND SETTING： Observation and comparison experiments at a cellular level were performed at the Department of Biochemistry and Molecular Biology, Tongji Medical College of Huazhong University of Science and Technology between February 2007 and February 2008.
MATERIALS： PAMD （95% purity） was provided by Kunming Institute of Botany, Chinese Academy of Sciences; melatonin was provided by Sigma, USA.
METHODS： N2a mouse neuroblastoma cells were cultured in vitro deprived of glucose, serum and oxygen for 90 minutes, then cultured in normal medium containing different concentrations of PAMD （0.1, 1.0, 10 mg/L） or melatonin （1, 10, and 100 μmol/L）. Cells cultured in normal conditions served as a control.
MAIN OUTCOME MEASURES： The culture solution was collected to determine the content of ex- citatory neurotransmitters such as glutamic acid and aspartic acid; cell viability was detected by MTT methods; reactive oxygen species production was determined by fluorescence spectroscopy; mito- chondrial transmembrane potential （？Ψm） was detected by laser confocal scanning; cytochrome C was measured by western blotting; and caspase-3 activity was determined by visible spectropho- tometry.
RESULTS： Melatonin and PAMD both promoted oxygen-glucose-serum deprivation-mediated N2a cell survival （P 〈 0.01） and inhibited glutamic acid release （P 〈 0.01）, but melatonin did not inhibit aspartic acid production. The protective effects were the strongest using melatonin 100 μmol/L and PAMD 10 mg/L, so subsequent experiments were the performed at those doses. Although PAMD could no longer maintain mitochondrial transmembrane potential 6 hours after reperfusion, its in- hibitory effects on cytochrome C release from mitochondria and scavengers of reactive oxygen species were stronger than those of melatonin （P 〈 0.01）. However, its inhibitory effect on caspase-3 activity was weaker than that of melatonin： PAMD could inhibit caspase-3 activity 12 hours after reperfusion （P 〈 0.01）, but melatonin inhibited caspase-3 activity 28 hours after reperfusion （P 〈 0.01）.
CONCLUSION： The results show that melatonin and PAMD have neuroprotective effects, but that the mechanisms are varied. Melatonin can maintain mitochondrial transmembrane potential, but its inhibitory effects on cytochrome C release, caspase-3 activity, and reactive oxygen species scav-enging are different from those of PAMD.     

Neuronal effects of SP600125 pretreatment in a rat model of cerebral ischemia/reperfusion injury Inhibited down-regulation of DNA repair protein

BACKGROUND： Recent studies have shown that the selective inhibitor of c-Jun N-terminal kinases （JNKs） signaling pathway, SP600125, exhibits neuronal protective effects in a rat model of brain ischemia/reperfusion. OBJECTIVE： To determine the mechanisms of neuroprotective effects of SP600125 in a rat model of brain ischemia/reperfusion, and determine the role of the JNK signaling pathway in SP600125-induced effects. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Animal Experiment Center, Medical School of Xi＇an Jiaotong University from June 2007 to September 2008. MATERIALS： SP600125 was provided by Biosource, USA; rabbit anti-phospho-JNK （Thr183/Tyr185） polyclonal antibody from Cell Signaling Technology, USA; rabbit anti-X-ray repair cross-complementing protein 1 （XRCC1） and anti-Ku70 polyclonal antibodies from Santa Cruz Biotechnology, USA; and TUNEL kit from Beijing Huamei Biology, China. METHODS： A total of 108 male, 4-month-old, Sprague Dawley rats were randomly assigned to three groups, with 36 rats per group. The sham operation group and ischemia/reperfusion group （I/R group） were intracerebroventricularly injected with 10 μL 1% DMSO. The SP600125-treated group （pre-SP group） was given 10 μL SP600125 （3 μg/μL）. Thirty minutes later, brain ischemia was induced in the I/R and pre-SP groups using the four-vessel occlusion method. Specifically, whole brain ischemia was induced for 6 minutes, and the clips were released to restore carotid artery blood flow. Rats from each group were observed at 2, 6, 12, 24, 48, and 72 hours, with 6 rats for each time point. The sham operation group was treated with the same surgical exposure procedures, with exception of occlusion of the carotid artery. MAIN OUTCOME MEASURES： Hematoxylin-eosin staining was used to observe neuronal survival in the hippocampal CA1 region, TUNEL was used to detect apoptosis in the hippocampal CA1 region, and immunohistochemistry was used to detect expression of phospho-JNK, XRCC1, and Ku70. RESULTS： Following brain ischemia/reperfusion, neuronal survival significantly decreased, and the number of apoptotic cells significantly increased （P 〈 0.01）. Compared with the I/R group, neuronal survival significantly increased in the pre-SP group, and the number of apoptotic cells significantly decreased （P 〈 0.01）. Expression of phospho-JNK increased, and XRCC1 and Ku70 significantly decreased （P 〈 0.05） following ischemia/reperfusion. Compared with the I/R group, expression of phospho-JNK decreased, and XRCC1 and Ku70 significantly increased in the pre-SP group （P 〈 0.05）. Correlation analysis revealed an inverse correlation between phospho-JNK gray value and XRCC1 and Ku70 gray values in the hippocampal CA1 region （r = -0.983, -0.953, P 〈 0.01）. CONCLUSION： SP600125 treatment decreased apoptosis induced by global brain ischemia/reperfusion in the rat hippocampal CA1 region. Results suggested that the neuroprotective effects were due to inhibited phosphorylation of JNK and reduced down-regulation of XRCC1 and Ku70.     

Influence of Ginkgo Biloba extract on beta-secretase in rat hippocampal neuronal cultures following chronic hypoxic and hypoglycemic conditions

BACKGROUND： Preparation of Ginkgo leaf has been widely used to improve cognitive deficits and dementia, in particular in Alzheirner＇s disease patients. However, the precise mechanism of action of Ginkgo leaf remains unclear. OBJECTIVE： To explore the effect of Ginkgo Biloba extract （Egb761）, Ginaton, on β -secretase expression in rat hippocampal neuronal cultures following chronic hypoxic and hypoglycemic conditions. DESIGN, TIME AND SETTNG： Completely by randomized, grouping study. The experiment was performed at the Laboratory of Molecular Imaging, Southeast University between August 2006 and August 2007. MATERIALS： A total of 128 Wistar rats aged 24 hours were selected, and hippocampal neurons were harvested for primary cultures. METHODS： On day 7, primary hippocampal neuronal cultures were treated with Egb761 （0, 25, 50, 100, 150, and 200μg/mL） under hypoxic/hypoglycemic or hypoglycemic culture conditions for 12, 24, and 36 hours, respectively. Hippocampal neurons cultured in primary culture medium served as control. MAIN OUTCOME MEASURES： Cell viability was assayed using 3-（4,5-Dimethylthiazol-2-yl）- 2,5-diphenyltetrazolium bromide （MTT）; fluorescence detection of β -secretase activity was performed; Western Blot was used to measure β -secretase expression. RESULTS： Cell viability under hypoxic/hypoglycemic or hypoglycemic culture conditions was significantly less than control cells （P 〈 0.05）. Under hypoxic/hypoglycemic or hypoglycemic culture conditions, treatment with 25 μg/mL Egb761 did not alter cell viability. However, 〉 25 μg/mL Egb761 induced greater cell viability （P 〈 0.05）. No differences were observed between hypoxic/hypoglycemic or hypoglycemic cells （P 〉 0.05）. α -secretase activity was increased after 12 hours in hypoxic/hypoglycemic culture （P 〈 0.01）. There were no significant differences between the 12-, 24-, or 36-hour Egb761 groups and the hypoxic/hypoglycemic groups （P 〉 0.05）. β -secretase activity was greater after     

阿尔茨海默病的不同诊断方法

阿尔茨海默病（AD）是一种进行性发展的神经系统退行性疾病,临床表现为认知和记忆功能不断下降,日常生活能力进行性减退,并伴有各种神经精神症状和行为障碍。目前AD的治疗仍然缺乏非常有效的药物,因此,早期发现、早期诊断对减缓病程进展、降低发病率和患病率具有重要意义。现就AD诊断的相关指标作一综述。     

Caspase 3 siRNA decreases apoptosis in cultureC neuronal cells

BACKGROUND： Lentiviral vectors, a type of retroviral vector, are able to infect cells at all phases of cell cycle. They are able to express exogenous target genes in vivo over long periods of time with limited immunological reaction.
OBJECTIVE： To inhibit neuronal apoptosis by blocking the apoptotic cascade reaction, gene silencing of Caspase 3, and transfection of Caspase 3 short hairpin ribonucleic acid （shRNA） into Neuro 2a cells using a lentiviral vector.
DESIGN： TiME-AND SETTING： An observational, genetic engineering cellular biology experiment was performed in Guangzhou Red Cross Hospital and Guangzhou Institute of Traumatic Surgery between March 2007 and June 2008.
MATERIALS： PLL3.7, PCMV-VSV-G, and PH＇8.9∧PR plasmids were provided by the CBR Institute for Biomedical Research, Harvard Medical School, USA. Staurosporine was purchased from Sigma, USA.
METHODS： Caspase 3 siRNA was synthesized and cloned into the PLL3.7 plasmid. The Caspase 3 shRNA-PLL3.7 Ientivirus was generated in 293T cells using a calcium phosphate transfection kit. After the lentivirus was transfected into Neuro 2a cells, apoptosis was induced in both the transfected and untransfected cells by staurosporine. Cell apoptosis was assessed by flow cvtometrv.
MAIN OUTCOME MEASURES： Caspase 3 mRNA expression was measured by RT-PCR and Caspase protein expression was assessed by Western blot. Cellular apoptosis was determined by flow cytometry using Annevin V-PE/Taad-Cy7. RESULTS： The transfection rate of caspase 3 shRNA was 〉 98% using the lentiviral vector, RT-PCR and Western blot results demonstrated that significantly reduced Caspase 3 mRNA and protein expression in the transfected Neuro 2a. The control group exhibited 38.7% Annexin V/7aad-positive cells, which suggested apoptotic anaphase, while only 5.0% cells in the Caspase 3 gene silencing group entered apoptotic anaphase. CONCKUSION： Caspase 3 shRNA inhibited Caspase 3 expression in Neuro 2a ceils and decreased drug-induced apoptosis of Neuro 2a cells.     

Environmental factors in the development and progression of late-onset Alzheimer＇s disease

Late-onset Alzheimer＇s disease （LOAD） is an age-related neurodegenerative disorder characterized by gradual loss of synapses and neurons, but its pathogenesis remains to be clarified. Neurons live in an environment constituted by neurons themselves and glial cells. In this review, we propose that the neuronal degeneration in the AD brain is partially caused by diverse environmental factors. We first discuss various environmental stresses and the corresponding responses at different levels. Then we propose some mechanisms underlying the specific pathological changes, in particular, hypothalamic-pituitary adrenal axis dysfunction at the systemic level; cerebrovascular dysfunction, metal toxicity, glial activation, and Aβ toxicity at the intercellular level; and kinase-phosphatase imbalance and epigenetic modification at the intracellular level. Finally, we discuss the possibility of developing new strategies for the prevention and treatment of LOAD from the perspective of environmental stress. We conclude that environmental factors play a significant role in the development of LOAD through multiple pathological mechanisms.     

Edema and neuronal apoptosis in the hippocampus and cortex of elderly rats following transient cerebral ischemia/reperfusion injury

BACKGROUND： Previous studies of cerebral ischemia have used young animals, with an ischemic time greater than 5 minutes （safe time limit）. Despite an increased understanding of neuronal apoptosis, it remains uncertain whether brief cerebral ischemic events of 5 minutes or less damage brain tissue in elderly rodents. OBJECTIVE： To investigate the effects of transient cerebral ischemia （5 minutes）/reperfusion injury on brain cortical and hippocampal edema, aquaporin-4 （AQP-4） expression, and neuronal apoptosis in aged rats, and to compare ischemic sensitivity between cortex and hippocampus. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Institute of Cerebrovascular Disease, Qingdao University Medical School from April 2008 to March 2009. MATERIALS： Rabbit anti-AQP-4 polyclonal antibody, TUNEL kit, and SABC immunohistochemistry kit were purchased from Wuhan Boster Bioengineering, China. METHODS： A total of 160 healthy, male, aged 19-21 months, Wistar rats were randomly assigned to 4 groups： sham-surgery, and ischemia 1-, 3-, and 5-minute groups, with 40 rats in each group. The global cerebral ischemia model was established using the Pusinelli four-vessel occlusion, and the three cerebral ischemia groups were subdivided into reperfusion 12-hour, 1-, 2-, 3-, and 7-day subgroups, with 8 rats in each subgroup. The sham-surgery group was subjected to exposure of the first cervical bilateral alar foramina and bilateral common carotid arteries. MAIN OUTCOME MEASURES： The dry-wet weight assay was used to measure brain water content and histopathology of the cortex and hippocampus was observed following hematoxylin-eosin staining. In addition, cortical and hippocampal AQP-4 expression was detected by streptavidin-biotin complex immunohistochemistry, and neuronal apoptosis was detected by the TUNEL method. RESULTS： There was no significant difference in brain water content or AQP-4 expression in the cortex and hippocampus between ischemia 1- and 3-minute groups and the sham-surgery group or brain water content or AQP-4 expression in the cortex between ischemia 5-minute group and sham-surgery group （P 〉 0.05）. However, brain water content and AQP-4 expression in the hippocampus after 5 minutes of cerebral ischemia were significantly increased compared with the sham-surgery group （P 〈 0.05 or P 〈 0.01）. Several TUNEL-positive cells were observed in the cortex and hippocampus of the sham-surgery group and ischemia 1-minute group, as well as in the cortex of the ischemia 3-minute group. In addition, the number of apoptotic neurons in the hippocampus of ischemia 3-minute group and in the cortex and hippocampus of ischemia 5-minute group was significantly increased （P 〈 0.05 or P 〈 0.01 ）. Neuronal apoptosis was increased after 12 hours of ischemia/reperfusion, and it reached a peak by 2 days （P 〈 0.01）. CONCLUSION： Transient cerebral ischemia （5 minutes） resulted in increased hippocampal edema, AQP-4 expression, and neuronal apoptosis. Moreover, cerebral ischemia had a greater effect on neuronal apoptosis than brain edema or AQP-4 expression, and the hippocampus was more sensitive than the cortex.     

高血压脑出血的显微外科治疗进展

高血压脑出血（Hypertensive intrac-rebral hemorrhage,HICH）是具有高发病率、高病死率、高致残率的急性脑血管疾病,占所有脑卒中患者的10%-20%,早期病死率可高达49.4%。随着人口老龄化,其发病率逐年提高;而外科手术的干预,使其病死率有所下降,但致残率居高不下。如何提高手术疗效和患者生存质量,一直是神经外科医师努力的方向。微侵袭血肿清除术因其手术创伤小,恢复快,是目前国内治疗高血压脑出血的重要手段。     

神经内镜联合亚低温治疗高血压基底节区脑出血

目的 探讨神经内镜联合亚低温在治疗高血压基底节区脑出血中的临床应用价值.方法 回顾性分析我院神经内镜治疗高血压基底节区脑出血患者40例的临床资料,并对治疗结果进行分析.结果 神经内镜治疗组22例(甲组),神经内镜联合亚低温治疗组18例(乙组),术后3个月根据GCS评分,甲组恢复良好1例,中残4例,重残6例,植物生存6例,死亡5例;乙组恢复良好4例,中残8例,重残3例,植物生存1例,死亡2例,两组比较差异有统计学意义(P＜0.05).两组颅内压比较第1天两者差异不明显,但第2、3天亚低温组颅内压明显降低.结论 神经内镜是治疗高血压基底节区脑出血较为有效的手术方式,联合亚低温治疗能有效降低颅内压,改善术后神经功能恢复,具有较好的临床应用价值.     

阿尔茨海默病治疗的研究进展

阿尔茨海默病（AD）是一种隐匿性起病,进行性恶化的神经退行性疾病,临床最初表现为认知功能障碍,并有可能在5～10年内完全衰退。患者往往伴随严重的记忆力丧失、精神行为异常、人格改变、言语功能障碍,无法独立生活,最终近乎于植物状态。Ferri等采用DISMOD软件在全球60岁以上人群中估计,全球的痴呆患者人数到2040年将达到8llO万左右。     

Upregulation of stromal cell-derived factor-1 alpha/CXCR4 axis-induced migration of human neural progenitors by tumor necrosis factor-alpha and interleukin-8

BACKGROUND： Studies of several animal models of central nervous system diseases have shown that neural progenitor cells （NPCs） can migrate to injured tissues. Stromal cell-derived factor 1 alpha （SDF-la）, and its primary physiological receptor CXCR4, have been shown to contribute to this process. OBJECTIVE： To investigate migration efficacy of human NPCs toward a SDF-1α gradient, and the regulatory roles of tumor necrosis factor-α （TNF-α） and interleukin-8 （IL-8） in SDF-1α/CXCR4 axis-induced migration of NPCs. DESIGN, TIME AND SETTING： An in vitro, randomized, controlled, cellular and molecular biology study was performed at the Laboratory of Department of Cell Biology, Medical College of Soochow University between October 2005 and November 2007. MATERIALS： SDF-1α and mouse anti-human CXCR4 fusion antibody were purchased from R＆D Systems, USA. TNF-αwas purchased from Biomyx Technology, USA and IL-8 was kindly provided by the Biotechnology Research Institute of Soochow University. METHODS： NPCs isolated from forebrain tissue of 9 to 10-week-old human fetuses were cultured in vitro. The cells were incubated with 0, 20, and 40 ng/mL TNF-α, or 0, 20, and 40 ng/mL IL-8, for 48 hours prior to migration assay. For antibody-blocking experiments, cells were further pretreated with 0, 20, and 40 μg/mL mouse anti-human CXCR4 fusion antibody for 2 hours. Subsequently, the transwell assay and CXCR4 blockade experiments were performed to evaluate migration of human NPCs toward a SDF-1α gradient. Serum-free culture medium without SDF-1α served as the negative control. MAIN OUTCOME MEASURES： The transwell assay was performed to evaluate migration of human NPCs toward a SDF-1α gradient, which was blocked by fusion antibody against CXCR4. In addition, CXCR4 expression in human NPCs stimulated by TNF-α and IL-8 was measured by flow cytometry. RESULTS： Results from the transwell assay demonstrated that SDF-1α was a strong chemoattractant for human NPCs （P 〈 0.01）, and 20 ng/mL produced the highest levels of migration. Anti-human CXCR4 fusion antibody significantly blocked the chemotactic effect （P 〈 0.05）. Flow cytometry results showed that treatment with TNF-α and IL-8 resulted in increased CXCR4 expression and greater chemotaxis efficiency of NPCs towards SDF-1α（P 〈 0.01）. CONCLUSION： These results demonstrated that SDF-la significantly attracted NPCs in vitro, and neutralizing anti-CXCR4 antibody could block part of this chemotactic function. TNF-α and IL-8 increased chemotaxis efficiency of NPCs towards the SDF-1αgradient by upregulating CXCR4 expression in NPCs.     

Targeting 13-secretase with RNAi in neural stem cells for Alzheimer＇s disease therapy

There are several major pathological changes in Alzheimer＇s disease, including apoptosis of cho- linergic neurons, overactivity or overexpression of 13-site amyloid precursor protein cleaving enzyme 1 （BACE1） and inflammation. In this study, we synthesized a 19-nt oligonucleotide targeting BACE1, the key enzyme in amyloid beta protein （AI3） production, and introduced it into the pSilenCircle vector to construct a short hairpin （shRNA） expression plasmid against the BACE1 gene. We transfected this vector into C17.2 neural stem cells and primary neural stem cells, resulting in downregulation of the BACE1 gene, which in turn induced a considerable reduction in reducing AI3 protein production. We anticipate that this technique combining cell transplantation and gene ther- apy will open up novel therapeutic avenues for Alzheimer＇s disease, particularly because it can be used to simultaneously target several pathogenetic changes in the disease.