Effects of long-term estrogen replacement therapy on beta-amyloid precursor protein and mRNA expression in ovariectomized rat hippocampus

BACKGROUND: In vitro cultures of neural stem cells have shown that estrogen can regulate beta-amyloid precursor protein (β-APP) metabolism and reduce amyloid-beta production.OBJECTIVE: To investigate the effects of long-term oral administration of compound nylestriol or low-dose 17beta-estradiol on β-APP and mRNA expression in the hippocampus of ovariectomized (OVX) rats. DESIGN, TIME AND SETTING: This randomized and controlled experiment was performed at the Animal Laboratory and Laboratory of Endocrine and Metabolic Disease, Xiangya Second Hospital of Central South University between April 2003 and May 2004.MATERIALS: According to body mass, 50 six-month-old female Sprague-Dawley rats were randomly divided into five groups (n = 10 per group): normal control, sham operation, OVX model, 17beta-estradiol (Sigma, USA), and compound nylestriol tablet (Laboratory of Endocrine and Metabolic Disease, Xiangya Second Hospital of Central South University) groups.METHODS: Rats in OVX plus 17beta-estradiol and OVX plus compound nylestriol tablet groups underwent ovariectomy. On the second day after surgery, rats were intragastrically given 17beta-estradiol (100 μg/kg), once per day or compound nylestriol tablet (0.5 mg/kg) and levonorgestrel (0.15 mg/kg) every 2 days.MAIN OUTCOME MEASURES: β-APP expression in the hippocampus of OVX rats was determined using immunohistochemistry (SABC method) and β-APP mRNA expression was analyzed by in situ hybridization. The results were quantitatively analyzed using cell counting and average optical density. RESULTS: The number and optical density of β-APP-positive neurons in every subregion of the hippocampus of OVX rats was dramatically increased compared with normal and sham operation groups following 35 weeks of administration (P < 0.05). Levels of β-APP were decreased following oral administration of compound nylestriol or 17beta-estradiol. In situ hybridization showed that long-term estrogen deficiency and oral administration of compound nylestriol or 17beta-estradiol did not alter the number of β-APP mRNA-positive neurons. CONCLUSION: The results show that long-term estrogen deficiency results in an increase of expression of β-APP though no changes in the expression of β-APP mRNA are detected. Replacement of estrogen with low-dose 17 beta-estradiol or compound nylestriol tablet inhibits the expression of β-APP in the hippocampus to the same extent.     

Effects of genistein and 17 beta-estradiol on hippocampal synaptophysin expression in ovariectomized rats***★

BACKGROUND： Phytoestrogen, derived from plants, is an estrogen-like element, and is effective and safe for estrogen replacement. OBJECTIVE： To compare the interventional effects of genistein and 17 S-estradiol on learning and memory and synaptophysin （SYN） expression in the hippocampus of ovariectomized rats.
DESIGN： Randomized controlled animal study.
SETTING： Department of Neurology, the Third Affiliated Hospital, Xiangya Medical College, Central South University.
MATERIALS： 130 healthy female Sprague Dawley （SD） rats, 6 months old and weighing （293.1 ± 10.2） g, were provided by the Second Xiangya Hospital of Central South University. This animal experiment received confirmed consent from the local ethics committee. All rats were randomly divided into 5 groups, including baseline group （n= 10）, sham operation group （n = 30）, ovariectomized group （n = 30）, genistein group （n = 30）, and 17 β -estradiol group （n = 30）. Rats in the latter four groups were observed for 3 weeks （n = 10） and for 15 weeks （n = 20） after model establishment.
METHODS： This study was performed at the Department of Endocrinology, the Second Affiliated Hospital, Xiangya Medical College, Central South University from August 2005 to January 2006. Animals were not submitted to any treatment in the baseline group, but anesthetized and sacrificed at the 7 months of age. After anesthesia in the ovariectomized, genistein, and 17 S-estradiol groups, both ovaries were separated and resected to establish an ovariectomized model. The same volume of fat was resected in the sham operation group. After surgery, rats were intraperitoneally injected with 5 mg/kg genistein in the genistein group,10μg/kg 17 β -estradiol in the 17 β-estradiol group, and 0.1 mL/100 g dimethyl sulfoxide （DMSO）/polyethylene glycol （PEG）-200 stock solution in the sham operation and ovariectomized groups once a day until one day before sacrifice.
MAIN OUTCOME MEASURES：① Learning and memory changes of SD r     

Influence of tonifying kidney recipe on advanced glycation endproducts and lipid peroxidation in ovariectomized rats☆

BACKGROUND： Previous studies have demonstrated that reduced estrogen levels may accelerate the formation of advanced glycation endproducts （AGE） in brain tissue, raise the concentration of lipid peroxidation products in vivo, and speed up deterioration of learning and memory. A tonifying kidney recipe is hypothesized to improve the ability of learning and memory in ovariectomized rats by downregulating AGE and lipid peroxidation products.
OBJECTIVE： To simulate a postmenopausal state, bilateral ovariectomy （OVX） was performed in rats, and the effects of tonifying kidney recipe （TKR） on AGE and lipid peroxidation in the rat cerebral cortex, hippocampus, and blood serum levels was measured. In addition, the effects on learning and memory were evaluated, and the effect of AGE -specific inhibitor aminoguanidine （AG） was compared with TKR.
DESIGN, TIME AND SETTING： A randomized, in vivo, control experiment was performed at the scientific research center （Provincial Key Laboratory） in the Fourth Hospital of Hebei Medical University （Shijiazhuang, Hebei Province, China） from May 2005 to January 2007.
MATERIALS： Forty healthy, adult, female, Sprague Dawley rats were used for this study. TKR was composed of prepared rehmannia rhizome, epimedium herb, desert-living cistanche, and Szechwan lovage rhizome, which were provided by Shijiazhuang Medical Materials Company （China）. A TKR extraction was prepared for further use. AG was provided by Sigma （USA）. Forty rats were randomly divided into four groups： sham, OVX, AG, and TKR, with 10 rats in each group.
METHODS： The rat ovaries were resected in the OVX, AG, and TKR groups, whereas the same volume of fat was resected in the sham group. At four weeks after OVX, the AG group received 1% AG water solution by lavage; the TKR group was administrated by lavage once per day at a dose of 6.3 g （crude drug）/kg; OVX and sham groups received equal volumes of tap water.
MAIN OUTCOME MEASURES： Learning and memory behavior of rat     

Effects of genistein and 17 beta-estradiol on hippocampal synaptophysin expression in ovariectomized rats

BACKGROUND:Phytoestrogen,derived from plants,is an estrogen-like element,and is effective and safe for estrogen replacement.OBJECTIVE:To compare the interventional effects of genistein and 17 β-estradiol on learning and memory and synaptophysin(SYN)expression in the hippocampus of ovariectomized rats.DESIGN:Randomized controlled animal study.SETTING:Department of Neurology,the Third Affiliated Hospital,Xiangya Medical College,Central South University. MATERIALS:130 healthy female Sprague Dawley(SD)rats,6 months old and weighing(293.1±10.2)g,were provided by the Second Xiangya Hospital of Central South University.This animal experiment received confirmed consent from the local ethics committee.All rats were randomly divided into 5 groups,including baseline group(n＝10),sham operation group(n＝30),ovariectomlzed group(n＝30),genistein group(n＝ 30),and 17 β-estradiol group(n＝30).Rats in the latter four groups were observed for 3 weeks(n＝10)and for 15 weeks(n＝20)after model establishment.METHODS:This study was performed at the Department of Endocrinology,the Second Affiliated Hospital,Xiangya Medical College,Central South University from August 2005 to January 2006.Animals were not submitted to any treatment in the baseline group,but anesthetized and sacrificed at the 7 months of age.After anesthesia in the ovariectomized,genistein,and 17 β-estradiol groups,both ovaries were separated and resected to establish an ovariectomized model.The same volume of fat was resected in the sham operation group.After surgery,rats were intraperitoneally injected with 5 mg/kg genistein in the genistein group,10 μ g/kg 17 β-estradiol in the 17 β-estradiol group,and 0.1 mL/100 g dimethyl sulfoxide (DMSO)/polyethylene glycol(PEG)-200 stock solution in the sham peration and ovariectomized groups once a day until one day before sacrifice.MAIN OUTCOME MEASURES:①Learning and memory changes of SD rats were detected using water maze behavioral testing 3 and 15 weeks after surgery.②SYN expression in the hippocampus was measured using immunohistochemistry. RESULTS:A total of 16 out of 130 rats died due to infection,and 114 rats were included in the final analysis.①Comparison of water maze results from the five groups:by 3 and 15 weeks after surgery, escape latency was prolonged and platform-crossing times decreased in the ovariectomized group compared to the baseline,genistein,17 β-estradiol,and sham operation groups(t＝4.17--14.64,P＜0.05).However, there were no significant differences in escape latency and platform-crossing times among the sham operation,genistein,and 17 β-estradiol groups(P＜0.05).②Distribution and quantity of SYN immunoreactive products in hippocampus:SYN-immunoreactive cells stained darkly in the baseline and sham operation groups,but were lightly stained in the genistein,17 β-estradiol,and ovariectomized groups.In particular,SYN-immunoreactive cells stained lightly in the ovariectomized group 15 weeks after surgery. SYN correction gray values in hippocampal sub-regions,especially in the mossy fiber layer of the CA3 region,of the ovariectomized group was lower compared to the baseline,sham operation,17 β-estradiol,and genistein groups(t＝12.57-23.92,P＜0.05)15 weeks after surgery.However,there were no significant differences in SYN correction gray values among the baseline,sham operation,17 β-estradiol and genistein groups(P＜0.05).CONCLUSION:Genistein or 17 β-estradiol supplemental therapy antagonizes memory deterioration,due to endogenous estrogen deficiency and blocks the decrease of SYN expression in the hippocampus.The effect of genistein is similar to 17 β-estradiol.     

马桑内酯激活星形胶质细胞条件培养液对大脑皮质及海马神经元雌、孕激素受体的影响

BACKGROUND： Coriaria lactone-activated astrocytes released bioactive substances that eventually caused epilepsy.
OBJECTIVE： It has been suggested that activated astrocytes alter the expression of the estrogen receptor and progesterone receptor by releasing bioactive substances during epilepsy, thereby affecting neuronal activity in the brain. This study was designed to observe the expression of the estrogen receptor and the progesterone receptor in rat brain following lateral ventricle injection of coriaria lactone-activated, astrocyte-conditioned medium.
DESIGN AND SETTING： This immunohistochemical, randomized, controlled, animal study was conducted at the Department of Pathology, Hospital Affiliated to Binzhou Medical College, China.
MATERIAL： Coriaria lactone was provided by Huaxi Pharmaceutical Factory, China. METHODS： Forty adult, healthy, male, Sprague Dawley rats were randomly assigned into two groups. Astrocyte-conditioned medium （10 μ L） was injected into rat lateral ventricle in the control group （n = 8）. Coriaria lactone-activated, astrocyte-conditioned medium （10 μL） was infused into the rat lateral ventricle in the coriaria lactone group （n = 32）. At 2, 4, 8 and 12 hours following injection, rats were sacrificed and subjected to immunohistochemistry. Eight rats were studied at each time point.
MAIN OUTCOME MEASURES： Behavioral changes were observed in rats of both groups. Expression of the estrogen receptor and the progesterone receptor in rat cortical and hippocampal neurons was measured using immunohistochemistry.
RESULTS： Four hours after injection, estrogen receptor levels in rat cortical and hippocampal neurons were significantly higher in the coriaria lactone group than in the control group （P 〈 0.05）. Progesterone receptor levels were significantly lower in the coriaria lactone group than in the control group （P 〈 0.05）. Seizures were not observed in the control group. In the coriaria lactone group, convulsions appeared 30 minutes after injection; seizures reached grade Ⅲ at 45 minutes rat behavior was nearly normal at 2 hours.
CONCLUSION： Activated astrocytes can induce seizures in the rat by enhancing estrogen receptor expression and decreasing progesterone receptor expression in cerebral cortical and hippocampal neurons.     

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.     

Effects of nanometer particles and water decoction of the Chinese medicine mixture of pinellia ternate and scorpion on P53 protein contents and apoptosis in the cerebral cortex and hippocampus of epileptic rats

BACKGROUND： Water decoction of the Chinese traditional medicine mixture of pinellia ternate and scorpion is an effective treatment for epilepsy.
OBJECTIVE： To compare nanometer particles and effects of water decoction of Chinese traditional medicine mixture on P53 protein levels and apoptosis in the cerebral cortex and hippocampus of epileptic rats.
DESIGN, TIME AND SETTING： This randomized, controlled molecular biology study was performed at the Key Laboratory of Child Neural Rehabilitation of Jiamusi University from October to December 2007.
MATERIALS： Forty healthy male Wistar rats were used in this study. Convulsion rat models were established by intraperitoneal infusion of 35 mg/kg pentylenetetrazol, once a day, for 28 successive days. The Chinese traditional medicine mixture, comprising pinellia ternate, scorpion, centipede, bupleurum, peach pit and glycyrrhiza, was purchased from Beijing Tongrentang, China. The mixture was made into nanometer particles and water decoction. The apoptosis determination kit and P53 immunohistochemistry kit were bought from Boster, China.
METHODS： Forty Wistar rats were randomly divided into four groups of ten rats per group, control, nanometer particle, water decoction and epileptic model groups. Rats in the nanometer particle and water decoction groups were respectively treated with 300 mg/kg Chinese herb nanometer particle suspension and water decoction by gavage, once a day, for 28 days. Rats in the epileptic model group were fed an equal volume of saline by gavage. Rats in the control group were only administered with the same volume of saline by gavage.
MAIN OUTCOME MEASURES： Terminal deoxynucleotidyl Transferase Biotin-dUTP Nick End Labeling （TUNEL） and immunohistochemistry were used to respectively detect neuronal apoptosis and P53 protein expression in the rat brain cortex and hippocampus at 28 days following administration.
RESULTS： The number of apoptotic neurons was lower in the nanometer particle and water decoction groups compared wi     

Effects of basic fibroblast growth factor on hippocampal and parietal cortical neuronal cAMP-response element-binding protein expression in a rat model of focal cerebral ischemia/reperfusion

BACKGROUND： cAMP-response element binding protein （CREB） is a key modulator of various signaling pathways. CREB activation initiates a series of intracellular signaling pathways that promote neuronal survival.
OBJECTIVE： To investigate the regulatory effects of basic fibroblast growth factor （bFGF） on cerebral neuronal CREB expression following ischemia/reperfusion injury.
DESIGN, TIME AND SETTING： An immunohistochemical detection experiment was performed at the Department of Anatomy, Shenyang Medical College, between October 2006 and April 2008.
MATERIALS： A total of 60 healthy, adult, Wistar rats were randomly divided into three groups： sham-operated （n =12）, ischemia/reperfusion （n = 24）, and bFGF-treated （n = 24）. Rabbit anti-rat CREB （1： 100） and biotin labeled goat anti-rabbit IgG were purchased from the Wuhan Boster Company, China. MetaMorph-evolution MP5.0-BX51 microscopy imaging system was provided by China Medical University, China. METHODS： Rat models of cerebral ischemia/reperfusion injury were developed using the suture method for right middle cerebral artery occlusion. Two-hour ischemia was followed by reperfusion. Rats from the bFGF-treated and ischemia/reperfusion groups were intraperitoneally administered endogenous bFGF （500 IU/mL, 2 000 IU/kg） or an equal amount of physiological saline. Rats from the sham-operated group underwent a similar surgical procedure, without induction of ischemia/reperfusion injury and drug administration.
MAIN OUTCOME MEASURES： After 48-hour reperfusion, hippocampal and parietal cortical neuronal CREB expression was detected by immunohistochemistry, and the absorbance of hippocampal CREB-positive products was determined using MetaMorph-evolutionMP5.0-BX51 microscopy imaging system.
RESULTS： The sham-operated group exhibited noticeable CREB expression in hippocampal and parietal cortical neurons. In the ischemia/reperfusion group, the CREB expression was discrete and neurons were poorly arranged. The bFGF-treated group exhibited increased CREB expression and better neuronal arrangement compared with the ischemia/reperfusion group. The mean absorbance of CREB-immunoreactive products in the hippocampus and parietal cortex was significantly higher in the ischemia/reperfusion group than in the sham-operated group （P 〈 0.05）, and significantly higher in the bFGF-treated group than in the ischemia/reperfusion group （P 〈 0.05）. CONCLUSION： bFGF significantly upregulates CREB expression in hippocampal and parietal cortical neurons following ischemia/reperfusion injury.     

在SK-N-SH细胞中抑制干预β-淀粉样前体蛋白裂解酶基因和淀粉样β前体蛋白基因

BACKGROUND： Previous studies have demonstrated that Piper futokadsura stem selectively inhibits expression of amyloid precursor protein （APP） at the mRNA level. In addition, the piperlonguminine （A） and dihydropiperlonguminine （B） components （1 ： 0.8）, which can be separated from Futokadsura stem, selectively inhibit expression of the APP at mRNA and protein levels. OBJECTIVE： Based on previous findings, the present study investigated the effects of β-site amyloid precursor protein cleaving enzyme （BACE1） and APP genes on the production of β-amyloid peptide 42 （Aβ42） in human neuroblastoma cells （SK-N-SH cells） using small interfering RNAs （siRNAs） and A/B components separated from Futokadsura stem, respectively. DESIGN, TIME AND SETTING： A gene interference-based randomized, controlled, in vitro experiment was performed at the Key Laboratory of Cardiovascular Remodeling and Function Research, Ministries of Education and Public Health, and Institute of Pharmacologic Research, School of Pharmaceutical Science ＆ Department of Biochemistry, School of Medicine, Shandong University between July 2006 and December 2007. MATERIALS： SK-N-SH cells were provided by Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai, China; mouse anti-human BACE1 monoclonal antibody was purchased from R＆D Systems, USA; mouse anti-human APP monoclonal antibody was purchased from Cell Signaling Technology, USA; and horseradish peroxidase （HRP）-conjugated goat anti-mouse IgG was provided by Sigma, USA. METHODS： The human BACE1 cDNA sequence was obtained from NCBI website （www.ncbi.nlm.nih.gov/sites/entrez）. Three pairs of siRNAs, specific to human BACE1 gene, were synthesized through the use of Silencer pre-designed siRNA specification, and were transfected into SK-N-SH cells with siPORT NeoFX transfection agent to compare the effects of different concentrations of siRNAs （10-50 nmol/L） on SK-N-SH cells. Futokadsura stem was separated and purified with chemical methods, and the crystal was composed of A/B components, with an A to B ratio of 1：0.8. The A/B （1 ： 0.8） components were added to the SK-N-SH cells at different concentrations （13.13, 6.56, and 3.28 mg/mL）. MAIN OUTCOME MEASURES： Using RT-PCR and Western blot methods, BACE1 and APP expression at mRNA and protein levels was detected in SK-N-SH cells following treatment with different siRNAs and concentrations of Futokadsura stem-separated A/B components, respectively. Altered Aβ42 secretion by SK-N-SH cells was determined by ELISA. RESULTS： BACE1 mRNA and protein levels were significantly suppressed by 40 and 50 nmol/L siRNAs at 48 hours post-transfection. A/B components （1 ： 0.8）, which were separated from Futokadsura stem, selectively inhibited mRNA and protein expression of APP in SK-N-SH cells. Aβ42 secretion by SK-N-SH cells was significantly decreased following treatment with siRNAs or A/B components. CONCLUSION： Inhibition of BACE1 and APP genes by various materials and methods efficiently decreased production of Aβ42.     

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.     

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.     

Wnt信号通路与骨髓间充质干细胞增殖及分化的关系

骨髓间充质干细胞（bonemarrow—derived mesenchymal stem cells,BMSCs）是骨髓中不同于造血干细胞的一类细胞,其来源丰富,取材简便,易分离、纯化、培养,在一定的条件下可以迅速体外扩增,具有多向分化潜能,可以通过不同的方法被诱导分化成骨细胞、软骨细胞、肌细胞、神经胶质细胞、神经元细胞等,而且它具有低免疫源性,向病变部位迁移的能力,     

Tissue with high intelligence quotient Adipose-derived stem cells in neural regeneration

The aim of the present review is to highlight the possible neuroregenerative potential ol adipose-derived stem cells. The key property of stem cells is plasticity including self-renewal, multilineage differentiation, and migration, whereas the required property is transplantability. For a long time, embryonic stem cells were thought to be the only source of pluripotency, a dogma that has been challenged during the last decade. Today, an alternative option might be adipose-derived stem cells, as easily accessible, ethical and autologous cellular source. Recent knowledge of adipobiology increasingly recognizes that adipose tissue is the major endo- and paracrine organ of the human body. Likewise, numerous neuropetides, neurotrophic factors, neurotransmitters, hypothalamic and steroid hormones and their receptors are shared by adipose tissue and brain. Accordingly, the regenerative potential of neuroprotective factor-secreting adipose-derived stem cells is outlined. Whether the possible benefits of adipose stem cell-based therapy may be mediated via cell transdifferentiation and/or paracrine mechanisms remains to further be evaluated.     

Comparison of rAAV-2-EGFP versus liposome transfection of neural stem cells

BACKGROUND： At present, a universal method and vector for transfecting enhanced green fluorescent protein （EGFP） into neural stem cells does not exist. The traditional use of liposome to transfect GFP shows low labeling efficiency and short labeling time. However, there is an increasing number of reports in recent years utilizing adeno-associated virus （AAV） transfection of neural stem cells. OBJECTIVE： To compare differences of neural stem cell transfection via rAAV-2-EGFP or liposome, with regard to transfection efficiency, stability, and safety. DESIGN, TIME AND SETTING： A parallel, controlled experiment at a cellular molecular level was performed in the Central Laboratory, Clinical Neuromedicine Research Center, Tongji Medical College, Huazhong University of Science and Technology, between June 2007 and March 2008. MATERIALS： Liposome 2000 was purchased from Invitrogen, USA; rAAV-2-EGFP was offered from Beijing AGTC Gene Technology, China. METHODS： Cerebral cortical cells from embryonic day 12 C57BL/6 mouse embryo were isolated and cultivated, and the logarithmically growing neural stem cells were divided into three groups. Liposome transfection： neural stem cells were transfected with liposome/EGFP plasmid mixture comprising 2 pg pcDNA-3.0-EGFP plasmid and 12 μg Liposome 2000 in complete culture solution. AAV transfection： neural stem cells were transfected with virus transfection solution comprising rAAV-2-EGFP and complete culture solution at multiplicity of infection = 10^5. Negative control： physiological saline was used instead of virus transfection solution. MAIN OUTCOME MEASURES： At different time points after transfection （36 hours, 1 week, 2 weeks, 1 month, and 6 months）, the proportion of green fluorescent cells was quantified under fluorescent microscopy. Transfection efficiency and proliferative activity of the transfected neural stem cells were detected with flow cytometry and 3-（4,5）-dimethylthiahiazo （-z-yl）-3,5-di- phenytetrazoliumremide, respectively. RESULTS： The neural stem cells began to express green fluorescence 36 hours after transfection with rAAV-2-EGFP. Transfection efficiency reached a peak （61.2%） at 1 week, and was higher than the liposome transfection group （38.7%; P 〈 0.05）. Green fluorescence was detectable for 6 months, with no weakness of expression, and rAAV-2-EGFP transfection showed no obvious effects on the proliferation activity of neural stem cells. In the liposome transfection group, green fluorescence was observed after 24 hours and reached a peak at 3 days. Fluorescence expression and proliferation activity disappeared at 2 weeks. CONCLUSION： rAAV-2-EGFP transfection of neural stem cells was superior to liposome transfection.     

Effects of Yishendaluo decoction on axonal degeneration, inflammatory reaction, and neurological function in a mouse model of experimental autoimmune encephalomyelitis

BACKGROUND： Yishendaluo decoction reduces production of inflammatory mediators, relieves damage due to inflammatory reactions, and improves neural functions during experimental autoimmune encephalomyelitis. OBJECTIVE： To investigate the effects of Yishendaluo decoction on a mouse model of experimental autoimmune encephalomyelitis. DESIGN, TIME AND SETTING： The randomized, controlled, neuropathological, and molecular biological animal study was performed at the Key Laboratory of Chinese Internal Medicine, Ministry of Education, Dongzhimen Hospital of Beijing University of Chinese Medicine and Center for Neuroinformatics, General Hospital of Chinese PLA from 2005 to 2006. MATERIALS： Yishendaluo decoction pieces consisting of prepared rehmannia root, colla comus cervi, cape jasmine fruit, and grassleaf sweetflag rhizome were purchased from the Dongzhimen Hospital of Beijing University of Chinese Medicine. Rabbit anti-mouse β-amyloid precursor protein and p38 polyclonal antibody （Zhongshan Goldenbridge Biotechnology, China）, as well interferon-y and interleukin-4 ELISA kit （Boster, China）, were used in this study. METHODS： A total of 96 healthy, female, SJL/J mice, aged 8 12 weeks, were equally and randomly assigned to normal, model, hormone, and Chinese medicine groups. A total of 0.2 mL antigen preparation, supplemented with 150 μg PLP 139-151 and 400 μg H37RA, was subcutaneously injected into the upper abdomen of mice from the model, hormone, and Chinese medicine groups. Mouse models of experimental autoimmune encephalomyelitis were established by intravenous injection of 0.1 mL Bordetella pertussis solution containing 0.6 × 10^6 Bordetella pertussis at days 1 and 3. Mice from the model, Chinese medicine, and hormone groups were respectively subjected to 0.2 mL saline, 2 g/kg Yishendaluo decoction, and 0.078 mg/kg prednisone acetate, once daily for 14 consecutive days. Mice from the normal group were left intact. MAIN OUTCOME MEASURES： Pathological changes were observed using hematoxylin-eosin staining and Luxol fast blue staining. Expression of β-amyloid precursor protein and p38 protein was determined by immunohistochemistry. Levels of interferon-y and interleukin-4 were detected by ELISA. Behavioral changes were assessed in mice according to scores of neurological function. RESULTS： A few inflammatory cell infiltration, nerve fiber breakage and slight demyelination were detected in the central nervous system of mice from the Chinese medicine and hormone groups compared with the model group. Expression of β-amyloid precursor protein and p38 protein was significantly diminished in the central nervous system of mice from the Chinese medicine and hormone groups compared with the model group （P 〈 0.05 or P 〈 0.01）, and the decrease was greatest in the Chinese medicine group. The decrease in mouse weight was not significant, and neurological function scores were less in the Chinese medicine and hormone groups compared with the model group （P 〈 0.05 or P 〈 0.01）. Interferon-y levels were significantly reduced （P 〈 0.01）, and interleukin-4 levels were significantly increased （P 〈 0.01） in the brains of the Chinese medicine and hormone groups, compared with the model group. CONCLUSION： Yishendaluo decoction improved neurological function in mice with experimental autoimmune encephalomyelitis by downregulating β-amyloid precursor protein expression, resistingaxonal degeneration, and relieving inflammatory reaction. The anti-inflammatory mechanism was regulated by inhibition of the p38 mitogen-activated protein kinase signal pathway.     

Effects of folic acid on in vitro astrocytic differentiation of neural stem cells from neonatal rats

BACKGROUND： Folic acid is essential for normal functioning of the nervous system. Previous studies have focused on the effects of folic acid on astrocyte proliferation. OBJECTIVE： To explore the effects of folic acid on astrocyte differentiation of neural stem cells （NSCs） and the related mechanisms in vitro. DESIGN, TIME AND SETTING： A randomized, controlled, grouping experiment was performed in Tianjin Medical University between August 2007 and October 2008. MATERIALS： Folic acid and 5-bromo-2-deoxyuridine （BrdU） were obtained from Sigma, MO, USA. Primary antibodies [rabbit anti-rat nestin, β-tubulin-Ⅲ, glial fibrillary acidic protein, and neurogeninl （Ngnl）; mouse anti-rat BrdU and β-actin monoclonal antibodies] were purchased from Santa Cruz Biotechnology, USA. METHODS： At 6 days of NSC proliferation from 24-hour-old neonatal rats, BrdU incorporation assay was performed. Seven days after primary culture, NSCs were induced to differentiate with medium containing 5% fetal bovine serum. Cultured NSCs were assigned to three groups： control, low-dose （liquid media with 8 mg/L folic acid）, and high-dose folic acid （liquid media with 44 mg/L folic acid）. MAIN OUTCOME MEASURES： At day 7 after primary culture, the cells were identified as NSCs by immunocytochemical methods. Double-label immunofluorescence technique for glial fibrillary acidic protein/BrdU detected differentiated cells 7 days after induction. Western blot was used to analyze expression of Ngnl protein in NSCs. RESULTS： In serum-free suspension medium, neurospheres comprised a large number of Nestin-, glial fibrillary acidic protein-, β-tubulin-Ⅲ-, and BrdU-positive cells. Compared with the control group, high-dose folic acid supplementation led to an marked increase in the percentage of glial fibrillary acidic protein/BrdU-positive cells （P 〈 0.05）, and significantly decreased Ngnl protein expression （P 〈 0.05）. CONCLUSION： Folic acid promotes astrocytic differentiation of NSCs, which might be related to downregulation of Ngnl protein expression.     

Monoamine alterations and rotational asymmetry in a rat model of Parkinson's disease following lateral ventricle transplantation of human amniotic epithelial cells

BACKGROUND： Human amniotic epithelial cells （HAECs） can differentiate into neurons, astrocytes and oligodendrocytes. They biologically secrete many active neurotrophins and have the capacity to metabolize dopamine enzymes. These features underlie a theoretical basis for the treatment of Parkinson＇s disease （PD）. OBJECTIVE： To investigate the survival and differentiation of transplanted HAECs in the lateral ventricle of PD model rats, and to explore its effect on circling behavior, as well as levels of dopamine （DA）, the metabolite homovanillic acid, dihydroxyphenyl acetic acid, 5-hydroxyindoleacetic acid, and 5-hydroxytryptamine in the striatum. DESIGN, TIME AND SETTING： A randomized, controlled, animal study was performed at the Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, and Shanghai Celstar Institute of Biotechnology from May 2007 to December 2008. MATERIALS： HAECs were derived from the placental chorion following caesarean delivery at the Shanghai International Matemal and Child Health Hospital. 6-hydroxydopamine （6-OHDA）, and mouse anti-human Vimentin monoclonal antibody were purchased from Sigma, USA; mouse anti-human nestin and tyrosine hydroxylase （TH） monoclonal antibodies were purchased from Chemicon, USA. METHODS： A total of 114 healthy, adult, Sprague Dawley rats were randomly assigned to two groups： PD model [n = 90, stereotactic microinjection of 2 μL 6-OHDA （3.5 μg/uL） into the striatum] and control （n = 24, no treatment）. The 51 successful PD model rats were randomly divided into 3 subgroups （n = 17）： HAEC, PBS, and model. The HAEC and PBS groups were respectively injected with 10 μL PBS solution containing 1 × 10^5/mL HAECs or 10 pL PBS into the lateral ventricle. The model group was not treated. MAIN OUTCOME MEASURES： TH protein expression in the striatum was evaluated by immunohistochemistry 5 weeks after HAEC transplantation. At 10 weeks, HAEC survival in the lateral ventricle was investigated by immunofluorescent staining; differentiation of HAECs in the lateral and third ventricles was examined by TH immunohistochemistry; concentrations of DA, homovanillic acid, dihydroxyphenyl acetic acid, 5-hydroxyindoleacetic acid, and 5-hydroxytryptamine in the striatum, as well as DA concentration in the cerebrospinal fluid, were measured with high-performance liquid chromatography-electrochemical detection. Circling behavior of PD model rats was consecutively observed for 10 weeks following intraperitoneal injection of amphetamine 1 week after successful model establishment. RESULTS： tn the HAEC group, the number of TH-positive cells significantly increased in the striatum, and circling behavior significantly decreased, compared with the PBS and model groups （P 〈 0.01）. In addition, monoamine concentrations in the striatum, as well as DA concentrations in the cerebrospinal fluid, significantly increased, compared with the PBS group （P 〈 0.05-0.01）. Moreover, a large number of nestin-, vimentin-, and TH-positive cells were observed in the lateral and third ventricles following HAEC injection.CONCLUSION： HAECs survived for 10 weeks with no overgrowth following transplantation into the lateral ventricle of PD model rats. Moreover, the cells differentiated into dopaminergic neurons, which increased DA secretion. HAEC transplantation improved cycling behavior in PD model rats.