Yizhijiannao Granule and a combination of its effective monomers,icariin and Panax notoginseng saponins,inhibit early PC12 cell apoptosis induced by beta-amyloid(25-35)

One of our previous studies showed that Yizhijiannao Granule,a compound Chinese medicine, effectively improved the clinical symptoms of Alzheimer’s disease.In the present study,we established a model of Alzheimer’s disease using beta-amyloid（25-35）in PC12 cells,and treated the cells with Yizhijiannao Granule and its four monomers,i.e.,icariin,catechin,Panax notoginseng saponins,and eleutheroside E.Flow cytometry showed that Yizhijiannao Granule-containing serum, icariin,Panax notoginseng saponins,and icariin＋Panax notoginseng saponins were protective against beta-amyloid（25-35）-induced injury in PC12 cells.Icariin in combination with Panax notoginseng saponins significantly inhibited early apoptosis of PC12 cells with beta-amyloid （25-35）-induced injury compared to icariin or Panax notoginseng saponins alone.The effects of icariin＋Panax notoginseng saponins were similar to the effects of Yizhijiannao Granule.The findings indicate that two of the effective monomers of Yizhijiannao Granule,icariin and Panax notoginseng saponins,can synergistically inhibit early apoptosis of PC12 cells induced by beta-amyloid（25-35）.

Neuroprotective effects of human telomerase reverse transcriptase on beta-amyloid fragment 25-35-treated human embryonic cortical neurons

BACKGROUND： Numerous current studies have suggested that human telomerase reverse transcriptase （hTERT） gene has neuroprotective effects and can inhibit apoptosis induced by various cytotoxic stresses; however, the mechanism of action remains unknown. OBJECTIVE： To evaluate the neuroprotective effects and possible mechanism of action of hTERT gene transfection in human embryonic cortical neurons treated with beta-amyloid fragment 25-35 （AI325-35）. DESIGN, TIME AND SETTING： The randomized, controlled and molecular biological studies were performed at the Department of Anatomy and Brain Research, Zhongshan School of Medicine, Sun Yat-sen University, China, from September 2005 to June 2008. MATERIALS： AdEasy-1 Expression System was gifted by Professor Guoquan Gao from Sun Yat-Sen University, China. Human cortical neurons were derived from 12-20 week old aborted fetuses, obtained from the Guangzhou Maternal and Child Health Hospital, China. Mouse anti-Odk5 and mouse anti-p16 monoclonal antibodies （Lab Vision, USA）, and mouse anti-hTERT monoclonal antibody （Epitomics, USA）, were used in this study. METHODS： （1） Recombinant adenovirus vectors, encoding hTERT （Ad-hTERT） and green fluorescent protein （Ad-GFP）, were constructed using the AdEasy-1 Expression System. Human embryonic cortical neurons in the Ad-hTERT group were transfected with Ad-hTERT for 1-21 days. Likewise, human embryonic cortical neurons in the Ad-GFP group were transfected with Ad-GFP for 1-21 days. Human embryonic cortical neurons in the control group were cultured as normal. （2） Human embryonic cortical neurons in the Ad-hTERT group were treated with 10 pmol/L Aβ25-35 for 24 hours. Normal human embryonic cortical neurons treated with 10 pmol/Lβ25.35 for 24 hours served as a model group. Human embryonic cortical neurons in the Ad-GFP and control groups were not treated with Aβ25-35. MAIN OUTCOME MEASURES： Expression of hTERT in human embryonic cortical neurons was evaluated by immunocytochemical staining and Western blot assay. Telomerase activity was measured using a PCR-based telomeric repeat amplification protocol （TRAP） ELISA kit. Neural activity in human embryonic cortical neurons was examined by MTT assay; apoptosis was measured using TUNEL assay; and Cdk5 and p16 protein expressions were measured by Western blot. RESULTS： Expression of hTERT protein was significantly increased and peaked at day 3 post-transfection in the Ad-hTERT group. No hTERT expression was detected in the Ad-GFP and control groups. Telomerase activity was significantly greater in the Ad-hTERT group compared with the Ad-GFP and control groups （P 〈 0.01）. Compared with the control group, cell activity was significantly decreased （P 〈 0.05）, and cell apoptotic rate, Cdk5 and p16 expression were significantly increased （P 〈 0.01） in the model group. Compared with the model group, cell activity was increased in the Ad-hTERT group, and peaked at day 3 post-transfection （P 〈 0.05）. Neuroprotective effects also peaked at day 3 post-transfection; and the apoptotic rate, Cdk5 and p16 expression significantly decreased （P 〈 0.01）. CONCLUSION： Expression of hTERT in human embryonic cortical neurons can relieve Aβ25-35-induced neuronal apoptosis. The possible mechanism by which hTERT produces these neuroprotective effects may be associated with inhibition of Cdk5 and p16 expression.

Effects of L-3-n-butylphthalide on caspase-3 and nuclear factor kappa-B expression in primary basal forebrain and hippocampal cultures after beta-amyloid peptide 1-42 treatment

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.

Protective Effect of Ecdysterone on PC12Cells Cytotoxicity Induced by Beta-amyloid_(25-35)

Objective： To examine the protective effect of ecdysterone （ECR） against beta-amyloid peptide fragment25-35 （Aβ25-35）-induced PC12 cells cytotoxicity, and to further explore its mechanism. Methods： Experimental PC12 cells were divided into the Aβ group （treated by Aβ25-35 100μmol/L）, the blank group （untreated）, the positive control group （treated by Vit E 100 μmol/L after induction） and the ECR treated groups （treated by ECR with different concentrations of 1, 50 and 100 μmol/L）. The damaged and survival condition of PC12 cells in various groups was monitored by lactate dehydrogenase （LDH） release and MTT assay. The content of malondialdehyde （MDA） was measured by fluorometric assay to indicate the lipid peroxidation. And the antioxidant enzymes activities in PC12 cells, including superoxide dismutases（SOD）, catalase （CAT） and glutathione peroxidase（GSH-Px）, were detected respectively. Results： After PC12 cells were treated with Aβ25-35 （100 μmol/L） for 24 hrs, they revealed a great decrease in MTT absorbance and activity of antioxidant enzymes, including SOD, CAT and GSH-Px as well as a significant increase of LDH activity and MDA content in PC12 cells （P〈0.01）. When the cells was pretreated with 1-100 μmol/L ECR for 24 hrs before Aβ25-35 treatment, the above-mentioned cytotoxic effect of Aβ25-35 could be significantly attenuated dose-dependently, for ECR 50 μmol/L, P〈0.05 and for ECR 100 μmol/L, P〈0.01. Moreover, ECR also showed significant inhibition on the Aβ25-35 induced decrease of SOD and GSH-Px activity, but not on that of CAT. Conclusion： ECR could protect PC12 cells from cytotoxicity of Aβ25-35, and the protective mechanism might be related to the increase of SOD and GSH-Px activities and the decrease of MDA resulting from the ECR-pretreatment.

Overexpression of estrogen receptor beta alleviates the toxic effects of beta-amyloid protein on PC12 cells via non-hormonal ligands

After binding to the estrogen receptor, estrogen can alleviate the toxic effects of beta-amyloid protein, and thereby exert a therapeutic effect on Alzheimer＇s disease patients. Estrogen can increase the incidence of breast carcinoma and endometrial cancer in post-menopausal women, so it is not suitable for clinical treatment of Alzheimer＇s disease. There is recent evidence that the estrogen receptor can exert its neuroprotective effects without estrogen dependence. Real-time quantitative PCR and flow cytometry results showed that, compared with non-transfected PC12 cells, adenovirus-mediated estrogen receptor β gene-transfected PC12 cells exhibited lower expression of tumor necrosis factor a and interleukin 1β under stimulation with beta-amyloid protein and stronger protection from apoptosis. The Akt-specific inhibitor Abi-2 decreased the anti-inflammatory and anti-apoptotic effects of estrogen receptor β gene-transfection. These findings suggest that overexpression of estrogen receptor β can alleviate the toxic effect of beta-amyloid protein on PC12 cells, without estrogen dependence. The Akt pathway is one of the potential means for the anti-inflammatory and anti-apoptotic effects of the estrogen receptor.

Gengnianchun recipe inhibits apoptosis of pheochromocytoma cells from beta-amyloid 25-35 insult, better than monotherapies and their compounds

This study aims to determine and compare the protective effects of Gengnianchun recipe drug serum and compounds of its representative drug monotherapies against sympathetic nerve pheochromocytoma cell line PC12 cells damaged by beta-amyloid 25-35 at the cellular apoptosis and related signal pathway levels. PC12 cells cultured with medicated rat serum showed enhanced cell viability and reduced cellular apoptosis rates compared with those of monotherapies and their compounds. Furthermore, Gengnianchun recipe up-regulated expressions of anti-apoptotic protein Bcl-2, estrogen receptor-beta and phosphorylated extracellular-signal-regulated kinase 1/2; and down-regulated expressions of pro-apoptotic proteins Bax and caspase-3. Gengnianchun recipe was superior to representative drug monotherapies, such as paeoniflorin, berberine, timosaponin A-III, icariine and their compounds in protecting PC12 cells. Mitogen-activated protein kinase blocker and estrogen receptor antagonist were found to reverse the above effects of Gengnianchun recipe. The experimental findings indicate that, Gengnianchun recipe protects PC12 cells from beta-amyloid 25-35 insult; its inhibitory effect on apoptosis may be achieved through the mitogen-activated protein kinase and estrogen receptor pathways.

Telencephalin protects Paju cells from beta-amyloid protein-induced apoptosis

Previous studies have confirmed that telencephalin （TLN） is a neural glycoprotein that protects axonal disruption induced by the beta-amyloid protein （Aβ42/35） in the neural crest-derived tumor cell line Paju. The present study investigated the effects of TLN on neuronal degeneration induced by Aβ42 in the differentiated Paju cell line. Results demonstrated that after cultivating cells in Aβ42 medium, the survival rate of Paju-TLN cells was significantly higher than that of Paju-neo cells, and that apoptotic rate was noticeably reduced. These results indicate that TLN reduces Paju cell apoptosis induced by Aβ42.

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.

Tau protein,phosphorylated tau protein,and beta-amyloid 42 levels in patients with neurodegenerative diseases complicated by cognitive deficits A non-randomized,concurrent,case-control investigation

BACKGROUND： The differential diagnosis of many neurodegenerative disorders depends primarily on clinical symptoms together with imaging methods. Recently, increased importance has been placed on the use of biomarkers for diagnosing various neurodegenerative disorders. OBJECTIVE： To assess the feasibility of tau-protein, phosphorylated tau-protein, beta-amyloid 42 （Aβ42）, and 14-3-3 protein as biomarkers for diagnosing several neurodegenerative diseases complicated by cognitive deficits. DESIGN, TIME AND SETTING： A non-randomized, concurrent, case-control investigation was performed in three medical centers in the Czech Republic （Department of Neurology at the University Hospital in Hradec Kralove, Department of Neurology at the 2rd Medical Faculty, and the University Hospital Motol） between October 2000 and November 2006. PARTICIPANTS： Eighteen patients with probable AIzheimer＇s disease, 4 patients with Creutzfeldt-Jakob disease, 10 patients with frontotemporal dementia, 9 patients with clinically isolated syndrome suggestive of multiple sclerosis, and 7 patients with multiple sclerosis, as well as 38 race-, nationality-, and age-matched cognitively intact controls, were included in the study. Diagnoses were established based on the following criteria： the criteria for Alzheimer＇s disease proposed by the National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer＇s Disease and Related Disorders Association, WHO criteria for Creutzfeldt-Jakob disease, Neary criteria for frontotemporal dementia, and McDonald＇s criteria for multiple sclerosis. All included patients were confirmed to suffer from various degrees of dementia. METHODS： Enzyme-linked immunosorbent assay was used to measure concentrations of tau-protein, phosphorylated tau-protein, and Aβ42 in cerebrospinal fluid （CSF） samples collected by standard lumbar puncture from each patient. Moreover, 14-3-3 protein was assessed by Western blot in CSF of Creutzfeldt-Jakob disease patients. Cognitive status was assessed using the Mini Mental Scale Examination （MMSE） in all subjects. MAIN OUTCOME MEASURES： Establishment of biomarkers with greatest specificity and sensitivity for the investigated disorders according to Receiver Operating Characteristic curves, which were based on values from patients and controls; correlation between concentrations of given biomarkers and demographic parameters, diagnosis, duration of disease, and level of cognitive deficit. RESULTS： Increased concentrations of total tau protein and phosphorylated tau protein, and decreased levels of Aβ42, in CSF of Alzheimer＇s disease patients reached the required sensitivity/specificity ratio of 80% or greater. A marked elevation in CSF concentrations of total tau protein showed even greater sensitivity than 14-3-3 protein in Creutzfeldt-Jakob disease. There was no association between selected biomarkers and frontotemporal dementia or multiple sclerosis. Phosphorylated tau-protein was the only biomarker that noticeably correlated with MMSE scores for Alzheimer＇s disease.CONCLUSION： Levels of total tau protein, phosphorylated tau protein, and A!342 in the CSF could differentiate patients with Alzheimer＇s disease and Creutzfeldt-Jakob disease from healthy controls and patients with other neurodegenerative disorders. The diversity of absolute values demonstrates the necessity to establish a specific standard for each laboratory.

Curcumin inhibits beta-amyloid protein 40/42 expression in the brain in a concentration-and time-dependent manner

Several studies have demonstrated that the amount of beta-amyloid （Aβ） protein in the brain can be lowered by down-regulating Aβ production, promoting Aβ degradation, reducing Aβ oligomerization or deposition, thereby alleviating symptoms of Alzheimer＇s disease. Curcumin has been known to be a peroxisome proliferator activated receptor gamma （PPARy） agonist and can obviously inhibit Aβ production and oligomerization. This study investigated the effects of curcumin on the G-site APP cleaving enzyme 1 （BACE1） activity and PPARy expression in human neuroblastoma SH-SY5Y cells, and validated the inhibitory effects of curcumin on Aβ40/42 expression in the brain. Results revealed that PPARy mRNA and protein expression in the human neuroblastoma SH-SY5Y cells significantly increased with increasing curcumin concentration and time course （P 〈 0.05）; BACE1 mRNA and protein expression and Aβ40/42 production significantly decreased with increasing curcumin concentration and time course （P 〈 0.05）. The changes in PPARy and BACE1 expression during Aβ production could be reversed by the PPARy antagonist GW9662. These findings indicate that curcumin reduced Aβ production by activating PPARy expression and inhibiting BACE1 expression in a concentration- and time-dependent manner.

Spatial structure of beta-amyloid Aβ_(1-40) in complex with a biological membrane model

The spatial structure of beta-amyloid Aβ1-40 in complex with sodium dodecyl sulfate micelles as a model membrane system was investigated by 1H-1H two-dimensional NMR (TOCSY, NOESY) spectroscopy and molecular dynamic method calculations. On the basis of NOE and chemical shifts changes data, spatial structure of the complex beta-amyloid-model of the cell surface membrane was obtained.

High-frequency magnetic stimulation attenuates beta-amyloid protein 1-42 neurotoxicity in organotypic hippocampal slices

Repetitive transcranial magnetic stimulation （rTMS） has been utilized as a therapeutic tool for neurodegenerative disorders including Alzheimer＇s disease. However, the precise mechanisms of its clinical effects remain unknown. β-amyloid （Aβ） exhibits direct neurotoxic effects and is closely related to neuronal degeneration in Alzheimer＇s disease. Therefore, it has been hypothesized that the neuroprotective effects of rTMS are related to the mechanisms of protection against Aβ neurotoxicity. Organotypic hippocampal slices were prepared from 8-day old, Sprague Dawley rats. The tissue slices were exposed to 100 μmol/L Al3142 since day 12 in vitro with and without high-frequency （20 Hz） magnetic stimulation. Magnetic stimulation efficacy was evaluated by measuring neuronal nuclei （NeuN） protein expression and by observing cultures following propidium iodide fluorescence staining and bromodeoxyuridine （BrdU） immunohistochemistry. Lactate dehydrogenase activity was detected in the culture media to evaluate hippocampal neuronal damage. Our results demonstrated that high-frequency magnetic stimulation significantly reversed the reduction of NeuN protein expression because of Aβ1-42 exposure （P 〈 0.05） and significantly reduced the number of damaged cells in the hippocampal slices （P 〈 0.05）. However, lactate dehydrogenase levels and anti-BrdU staining results did not reveal any statistical differences These findings indicate that high-frequency magnetic stimulation might have protective effect on hippocampal neurons from Aβ1-42 neurotoxicity.

Effects of natural cerebrolysin on protective proteins and pro-apoptotic molecules in mesenchymal stem cells following beta-amyloid peptide1-40-induced endoplasmic reticulum stress

BACKGROUND： Studies have demonstrated that β-amyloid peptide （Aβ）, a characteristic pathological product of Alzheimer＇s disease （AD）, results in neuronal endoplasmic reticulum stress （ERS）. However, the mechanisms of traditional Chinese medicine against ERS in AD are poorly understood. OBJECTIVE： To measure expression levels of protective proteins （GRP78 and GRP94） of ER molecular partners and pro-apoptotic Caspase-12 ER membrane expression following application of traditional Chinese medicine natural cerebrolysin （NC） to treat Aβ1-40-induced ERS. DESIGN, TIME AND SETTING： A parallel-controlled study was performed at the Institute of Integrated Western and Traditional Chinese Medicine, Shenzhen Hospital of Southern Medical University between September 2006 and November 2008. MATERIALS： Sprague Dawley male rats, 6-8 weeks old, were used to harvest tibial and femoral bone marrow. Isolation and purification of mesenchymal stem cells （MSCs） were established from the whole bone marrow by removing non-adherent cells in primary and passage cultures. Aβ1-40 was provided by Sigma, USA. NC was provided by Shenzhen Institute of Integrated Chinese and Western Medicine, China. NC was predominantly composed of Renshen （Radix Ginseng）, Tianma （Rhizoma Gastrodiae）, and Yinxingye （Ginkgo Leaf） in a proportion of 1 ： 2： 2. Following conventional water extraction technology, an extract （1 ： 20） was prepared. Six adult, male, New Zealand rabbits underwent intragastric administration of NC extract （0.976 g/kg per day） for 1 month to prepare NC-positive serum, and the remaining 6 rabbits received intragastric administration of physiological saline to prepare normal blank serum. METHODS： A total of 500 nmol/L Aβ1-40 was used to establish ERS models of primary cultured MSCs. AD cell models were incubated with different doses of NC-positive serum （2.5%, 5%, and 10%）. MSCs treated with normal blank serum served as normal blank controls. MAIN OUTCOME MEASURES： Reverse transcription-polymerase chain reaction and fluorescent immunocytochemistry were respectively used to measure mRNA and protein expression levels of GRP78, GRP94, and Caspase-12 in MSCs. RESULTS： Following Aβ1-40 exposure, mRNA and protein expression levels of GRP78 and GRP94, as well as Caspase-12, significantly increased （P 〈 0.05）, suggesting successful establishment of ERS models. Following NC-positive serum application, mRNA and protein expression levels of GRP78 and GRP94 in MSCs significantly increased （P 〈 0.05 or P 〈 0.01）. However, mRNA and protein expression levels of Caspase-12 significantly decreased （P 〈 0.05, or P 〈 0.01） compared with the ERS model group. These effects were dose-dependent. CONCLUSION： NC downregulated Caspase-12 expression and upregulated GRP78 and GRP94 expression in MSCs in a dose-dependent manner under the state of Aβ1-40-induced ERS.

Nasal mucosal inhalation of amyloid-beta peptide 3–10 defective adenovirus attenuates cytotoxicity induced by beta-amyloid(1–42)

Three-month-old Alzheimer＇s disease model transgenic mice were immunized with Aβ1-42, Plp-Adenovirus [Ad]-X-CMV-（Aβ3-10）lo-CpG [AdCpG-（Aβ3-10）1] or AdCpG virus fluid via na- sal mucosal inhalation, respectively. ELISA analysis of serum showed Aβ42 antibody titers were significantly increased in mice immunized with Aβ1-42 and AdCpG-（Aβ3-10）10. Concanavalin A and AdCpG-（Aβ3-10）10 stimulation significantly increased the number of proliferating spleen cells cultured from AdCpG（Aβ3-10）Io and Aβ42 groups compared with the control group. In the AdCp- G（Aβ3-10）10 group, levels of interleukin （IL）-4 and IL-10 were increased, while those of IL-2 and interferon-y were decreased. In the A[342 group, levels of IL-4, IL-10, IL-2 and interferon-y were all increased. Experimental findings indicate that AdCpG-（Aβ3-10）10 vaccine can produce strong T helper 2 （Th2） humoral immune responses in addition to the production of Aβ42 antibody. The cellular immunologic response was weak and avoided Aβ1-42-mediated cytotoxicity.

关于抗Aβ单克隆抗体的临床应用建议(2024版)

最新研发的抗Aβ单克隆抗体陆续在国内外获批上市,并逐渐应用于我国临床实践。为促进抗Aβ单克隆抗体在我国阿尔茨海默病治疗中更合理、安全的应用,本文结合抗Aβ单克隆抗体现有临床试验证据及阿杜卡单抗在上海交通大学医学院附属瑞金医院海南医院的临床应用经验,总结抗Aβ单克隆抗体的临床应用建议,包括临床用药指征、用药前评估及准备、用药时医嘱及注意事项、用药后临床监测,旨在为临床医师提供翔实的用药指导和建议。

β淀粉样蛋白25-35对BV2细胞TREM2/NF-κB信号通路的影响

目的:探讨不同浓度β-淀粉样蛋白25-35(Aβ25-35)对小胶质细胞髓样细胞触发受体2(TREM2)/核转录因子-κB(NF-κB)信号通路的影响。方法:将BV2细胞随机分为5组,分别加入0、5、10、20、40μmol/L的Aβ25-35,作用24、48 h,镜下观察细胞形态,CCK-8法测定细胞活性,酶联免疫吸附实验(ELISA)测定肿瘤坏死因子-α(TNF-α)表达,实时荧光反转录-聚合酶链反应(RT-PCR)测定NF-κBp65、TREM2 mRNA表达。结果:显微镜下观察干预48 h后Aβ25-35≥10μmol/L细胞成片死亡,干预24 h后,CCK-8检测显示,不同浓度Aβ25-35干预BV2细胞的存活率均>70%,ELISA和RT-PCR检测显示,Aβ25-3520μmol/L和40μmol/L组促炎因子TNF-α和TREM2 mRNA的表达均明显升高,Aβ25-3520μmol/L的NF-κB p65 mRNA表达明显升高,与对照组相比差异有统计学意义(P<0.05)。结论:Aβ25-35浓度20μmol/L作用24 h,能够激活小胶质细胞发生炎症反应,可能与TREM2/NF-κB信号通路的激活有关。

虎杖苷对β淀粉样蛋白诱导体外皮质神经元线粒体氧化应激和功能障碍的保护作用

目的探讨虎杖苷对β淀粉样蛋白25~35(Aβ_(25~35))诱导的原代培养大鼠皮质神经元损伤的保护作用及可能的作用机制。方法原代培养SD大鼠皮质神经元,分为对照组、虎杖苷组、Aβ_(25~35)组和联合组(Aβ_(25~35)+虎杖苷)。采用四甲基偶氮唑盐检测皮质神经元活力,2,7-二氯荧光素二乙酸酯探针或红色线粒体超氧化物荧光探针染色检测细胞内和线粒体活性氧水平,线粒体膜通透性转换孔(MPTP)试剂盒检测MPTP开放程度,蛋白免疫印记法检测细胞色素C及线粒体转录因子A(TFAM)表达。另外,测定细胞内电子传递链复合物(包括复合物Ⅰ、Ⅱ、Ⅲ、Ⅳ)活性和三磷酸腺苷(ATP)水平。采用高效液相色谱法测定线粒体中8-羟基脱氧鸟苷(8-OHdG)。结果与对照组比较,Aβ_(25~35)组皮质神经元细胞活力、线粒体荧光强度、线粒体呼吸链酶活性(复合物Ⅰ、Ⅱ、Ⅲ、Ⅳ)、细胞内ATP、线粒体内TFAM表达明显降低,差异有统计学意义(P<0.05,P<0.01);与Aβ_(25~35)组比较,虎杖苷组线粒体荧光强度、线粒体呼吸链酶活性(复合物Ⅰ、Ⅱ、Ⅲ、Ⅳ)、细胞内ATP、线粒体内TFAM表达明显增高,皮质神经元暴露3、6、12、24h细胞内和线粒体内活性氧明显降低(P<0.05,P<0.01),联合组细胞色素C细胞质/线粒体比值、线粒体内8-OHdG水平明显低于Aβ_(25~35)组[3.02±0.28 vs 5.73±0.45,P<0.05;(8.07±1.45)×10^(6)dG vs(16.07±2.29)×10^(6)dG,P<0.05]。结论虎杖苷可有效地保护皮质神经元免受Aβ_(25~35)诱导的损伤,至少部分作用是通过抑制线粒体氧化应激和改善线粒体功能实现。

高原鼠兔、高原鼢鼠肠道菌群对低压低氧环境下大鼠海马组织Aβ、Tau及BDNF蛋白的影响

为了探究暴露低压低氧不同时间以及移植高原鼠兔、高原鼢鼠肠道菌群后暴露低压低氧环境是否会影响SD大鼠海马组织β淀粉样蛋白(beta-amyloid protein, Aβ)、tau及脑源性神经营养因子(brain-derived neurotrophic factor, BDNF)的表达水平,首先将SD大鼠随机分为常氧组、低压低氧组和低压低氧处理组,低压低氧组根据暴露低压低氧时间又分为第1、3、7、15、28天组,低压低氧处理组则根据处理因素分为低压低氧对照组、低压低氧+抗生素处理组、低压低氧+抗生素+鼢鼠菌处理组、低压低氧+抗生素+鼠兔菌处理组、低压低氧+抗生素+SD大鼠菌处理组(10只/组),共11组;然后采用尼氏染色观察常氧组和低压低氧组海马组织神经细胞的形态变化,采用Western-blot检测各组Aβ、tau及BDNF蛋白表达水平。结果显示,与常氧组相比,低压低氧组从第3天开始海马组织CA1区的神经细胞排列疏松紊乱,细胞核固缩明显,并具有时间依赖性;Aβ、tau蛋白水平分别从低压低氧暴露第7天、3天开始显著升高,并随低压低氧暴露时间的延长进一步升高,其中以tau蛋白升高尤为明显;BDNF蛋白在低压低氧暴露初期显著升高,而后随低压低氧暴露时间的延长逐渐降低,与Aβ和tau蛋白水平呈现显著的负相关。此外,与抗生素处理组相比,在低压低氧环境下,移植高原鼠兔肠道菌群的大鼠海马组织中Aβ、tau蛋白的表达显著下降, BDNF的表达明显升高。实验结果初步表明,低压低氧可上调大鼠海马组织Aβ、tau蛋白表达,下调BDNF蛋白表达;肠道菌群移植可上调低压低氧环境下大鼠海马组织BDNF蛋白的表达,同时影响Aβ、tau蛋白的表达,其中高原鼠兔肠道菌群移植大鼠海马组织中的Aβ、tau蛋白水平被下调,高原鼢鼠肠道菌群移植大鼠海马组织中的tau蛋白水平被上调, Aβ蛋白水平被下调。

基于网络药理学和实验研究槲皮素治疗阿尔兹海默病的机制

目的通过网络药理学和实验验证和探究槲皮素(quercetin)治疗阿尔兹海默病(Alzheimer’s disease,AD)的作用机制。方法通过TCMSP、Swiss Target Prediction和Uniprot数据库筛选槲皮素对应的作用靶点。通过TCMIP V2.0、TCMSP、TTD、DrugBank、CTD和DisGeNET数据库得到与AD发病机制相关的靶点,并与槲皮素作用靶点进行映射,将得到的交集靶点作为槲皮素治疗AD的靶点。通过String数据库、CytoNCA和MCODE插件对槲皮素治疗AD的靶点进行各蛋白之间的相互作用研究,作用强的靶点为槲皮素治疗AD的关键靶点。将槲皮素治疗AD的靶点通过Cytoscape 3.8.2软件的ClueGO插件和DAVID数据库进行GO和KEGG信号通路富集分析。用蛋白印迹法(Western blotting)和实时荧光定量聚合酶链式反应(real-time fluorescence quantitative polymerase chain reaction,qRT-PCR)对预测的通路进行初步验证。结果筛选出与槲皮素作用的靶点有230个,与442个AD疾病靶点重合的靶点有43个,该靶点涉及多个生物学过程和54条信号通路。通过聚类分析和网络拓扑参数,得到槲皮素治疗AD的6个关键靶点,包括糖原合成酶激酶-3β(glycogen synthase kinase-3β,GSK3β)、血管内皮生长因子A(vascular endothelial growth factor A,VEGFA)、淀粉样βA4蛋白(amyloidβA4 protein,APP)、磷脂酰肌醇3-激酶调节亚单位α(phosphatidylinositol 3-kinase regulatory subunitα,PIK3R1)、白细胞介素-6(interleukin-6,IL-6)、胰岛素样生长因子Ⅱ(insulinlike growth factorⅡ,IGF2)和转化生长因子β1(transforming growth factor beta-1,TGFβ1);细胞实验结果表明,槲皮素可提高AD细胞模型中的蛋白激酶B(protein kinase B,AKT),GSK-3βmRNA水平,与调控AKT/GSK-3β通路的磷酸化有关。结论槲皮素可增强损伤神经细胞的稳定性、改善细胞膜的通透性,从而稳定细胞内环境。该作用可能与槲皮素提高AD细胞模型中的AKT、GSK-3β等mRNA水平,调控AKT/GSK-3β通路的磷酸化有关。

β淀粉样蛋白42寡聚体诱导神经元毒性和阿尔茨海默病病理形成

目的探究β淀粉样蛋白(Aβ)42寡聚体对神经元毒性的作用及诱导产生类似阿尔茨海默病(AD)病理的机制。方法采用Western blot检测和透射电子显微镜对合成的Aβ_(42)寡聚体进行鉴定。为评估Aβ_(42)寡聚体的影响,使用2,5-二苯基四氮唑溴盐检测细胞活性,将10μmol/L的Aβ_(42)寡聚体与人神经母细胞瘤系(SH-SY5Y)细胞共孵育12h和24h,与人胚胎干细胞(hESC)衍生的谷氨酸能神经元共孵育24h、48h和96h,同时设立相应对照组。原位末端标记法检测谷氨酸能神经元凋亡情况;免疫荧光染色法检测AD相关病理Aβ斑块及p-tau病理变化。结果Western blot显示,Aβ_(42)寡聚体样品中观察到单体和小分子量聚集体(<30000)。透射电子显微镜成像显示,Aβ_(42)寡聚体主要呈圆球形颗粒状。10μmol/L的Aβ_(42)寡聚体与SH-SY5Y细胞共孵育12h、24h,细胞存活率显著低于其对照组[(70.89±2.54)%vs(100.00±2.02)%,(52.63±3.37)%vs(100.00±2.80)%,P<0.05]。10μmol/L的Aβ_(42)寡聚体与谷氨酸能神经元共孵育24h、48h和96h,细胞存活率显著低于其对照组(P<0.05)。10μmol/L的Aβ_(42)寡聚体与谷氨酸能神经元共孵育48h、96h,凋亡率显著高于其对照组[(1.44±0.31)%vs(1.00±0.38)%,(1.75±0.64)%vs(1.00±0.31)%,P<0.05]。10μmol/L的Aβ_(42)寡聚体与谷氨酸能神经元共孵育24h、48h、96h,均产生呈圆形颗粒状的Aβ斑块阳性信号,其对照组均无Aβ斑块阳性信号。10μmol/L的Aβ_(42)寡聚体与谷氨酸能神经元共孵育24h,细胞在Thr231位点处产生tau过度磷酸化,Aβ_(42)寡聚体组平均荧光强度显著高于其对照组(P<0.05)。结论Aβ_(42)寡聚体对SH-SY5Y细胞和谷氨酸能神经元均具有毒性,可以诱导谷氨酸能神经元产生AD样病理。