Alzheimer's disease is pathologically defined by accumulation of extracellular amyloid-β(Aβ). Approximately 25 mutations in β-amyloid precursor protein(APP) are pathogenic and cause autosomal dominant Alzheimer...Alzheimer's disease is pathologically defined by accumulation of extracellular amyloid-β(Aβ). Approximately 25 mutations in β-amyloid precursor protein(APP) are pathogenic and cause autosomal dominant Alzheimer's disease. To date, the mechanism underlying the effect of APP mutation on Aβ generation is unclear. Therefore, investigating the mechanism of APP mutation on Alzheimer's disease may help understanding of disease pathogenesis. Thus, APP mutations(A673T, A673 V, E682 K, E693 G, and E693Q) were transiently co-transfected into human embryonic kidney cells. Western blot assay was used to detect expression levels of APP, beta-secretase 1, and presenilin 1 in cells. Enzyme-linked immunosorbent assay was performed to determine Aβ_(1–40) and Aβ_(1–42) levels. Liquid chromatography-tandem mass chromatography was used to examine VVIAT, FLF, ITL, VIV, IAT, VIT, TVI, and VVIA peptide levels. Immunofluorescence staining was performed to measure APP and early endosome antigen 1 immunoreactivity. Our results show that the protective A673 T mutation decreases Aβ_(42)/Aβ_(40) rate by downregulating IAT and upregulating VVIA levels. Pathogenic A673 V, E682 K, and E693 Q mutations promote Aβ_(42)/Aβ_(40) rate by increasing levels of CTF99, Aβ_(42), Aβ_(40), and IAT, and decreasing VVIA levels. Pathogenic E693 G mutation shows no significant change in Aβ_(42)/Aβ_(40) ratio because of inhibition of γ-secretase activity. APP mutations can change location from the cell surface to early endosomes. Our findings confirm that certain APP mutations accelerate Aβ generation by affecting the long Aβ cleavage pathway and increasing Aβ_(42/40) rate, thereby resulting in Alzheimer's disease.展开更多
BACKGROUND: During onset and development of Alzheimer's disease, β-amyloid (Aβ) precursor protein (APP), β-site amyloid precursor protein cleaving enzyme (BACE), and β-amyloid are key genes and proteins in...BACKGROUND: During onset and development of Alzheimer's disease, β-amyloid (Aβ) precursor protein (APP), β-site amyloid precursor protein cleaving enzyme (BACE), and β-amyloid are key genes and proteins in the Aβ pathway, and over-expression of these genes can lead to Aβ deposit/on in the brain. OBJECTIVE: To observe the influence of Longyanshen polysaccharides on expression of BACE, APP, and Aβ in the senescence-accelerated mouse prone/8 (SAMP8) brain, and to compare these effects with huperzine A treatment. DESIGN, TIME AND SETTING: A randomized, controlled, neurobiochemical experiment was performed at the Department of Pharmacology and Scientific Experimental Center of Guangxi Medical University from September 2005 to January 2008. MATERIALS: Longyanshen polysaccharfdes powder was extracted from the dried slices of the medicinal plant Longyanshen. The active component, Longyanshen polysaccharides, was provided by the Department of Pharmacology, Guangxi Medical University; huperzine A was purchased from Yuzhong Drug Manufactory, China. METHODS: Healthy SAMP8 mice were used to establish a model of Alzheimer's disease. A total of 50 SAMP8 mice were randomly assigned to 5 groups (n = 10): SAMP8, huperzine A, low-, middle-, and high-dose polysaccharides. In addition, 10 senescence-accelerated mouse resistant 1 (SAMR1) mice were selected as normal controls. SAMP8 and SAMR1 mice were administered 30 mL/kg normal saline; the huperzine A group was administered 0.02 mg/kg huperzine A; the low-, middle-, and high-dose polysaccharides groups were respectively administered 45, 90, and 180 mg/kg Longyanshen polysaccharides. Each group was treated by intragastric administration, once per day, for 50 consecutive days. MAIN OUTCOME MEASURES: One hour after the final administration, immunohistochemical analysis was used to determine Aβ expression in the cortex and hippocampus of SAMP8 mice. Reverse-transcription polymerase chain reaction was used to determine mRNA levels of BACE and APP in SAMP8 brain tissue. RESULTS: Compared with the SAMR1 group, Aβ expression in the cerebral cortex and hippocampus, as well as expression of BACE, APP mRNA in the brain was significantly increased in the SAMP8 group (P 〈 0.05-0.01). Compared with the SAMP8 group, Aβ expression, as well as BACE and APP mRNA expression, were significantly decreased in the cerebral cortex and hippocampus of huperzine A and low-, middle-, and high-dose polysaccharides groups (P 〈 0.05-0.01). In particular, the effect of high-dose polysaccharides was the most significant (P 〈 0.05-0.01 ). CONCLUSION: Longyanshen polysaccharides reduced or inhibited over-expression of BACE, APP, and Aβ in SAMP8 mice in a dose-dependent manner, and the effect was not worse than huperzine A.展开更多
Previous studies have reported that non-human primates and rodents exposed to lead during brain development may become dependent on the deposition of pre-determined β-amyloid protein (Aβ),and exhibit upregulation ...Previous studies have reported that non-human primates and rodents exposed to lead during brain development may become dependent on the deposition of pre-determined β-amyloid protein (Aβ),and exhibit upregulation of β-site amyloid precursor protein expression in old age.However,further evidence is required to elucidate the precise relationship and molecular mechanisms underlying the effects of early lead exposure on excessive Aβ production in adult mammals.The present study investigated the effects of lead exposure on expression of β-amyloid precursor protein cleavage enzyme-1 (BACE-1) in the rat retina and the production of Aβ in early development,using the retina as a window for studying Alzheimer's disease.Adult rats were intraocularly injected with different doses of lead acetate (10μmol/L,100μmol/L,1 mmol/L,10 mmol/L and 100 mmol/L).The results revealed that retinal lead concentration,BACE-1 and its cleavage products β-C-terminal fragment and retina Aβ1-40 were all significantly increased in almost all of the lead exposure groups 48 hours later in a dose-dependent manner.The only exception was the 10μmol/L group.The distribution of BACE-1 in the retina did not exhibit obvious changes,and no distinctive increase in the activation of retinal microglia was apparent.Similarly,retinal synaptophysin expression did not exhibit any clear changes.These data suggest that lead exposure can result in the upregulation of retinal neuron BACE-1 expression in the early period of development and further increase the overproduction of Aβ1-40 in the retina.Our results provided novel insight into the molecular mechanisms underlying environmentally-induced Alzheimer's disease.展开更多
In this study, we employed chromatin immunoprecipitation, a useful method for studying the locations of transcription factors bound to specific DNA regions in specific cells, to investigate amyloid precursor protein i...In this study, we employed chromatin immunoprecipitation, a useful method for studying the locations of transcription factors bound to specific DNA regions in specific cells, to investigate amyloid precursor protein intracellular domain binding sites in chromatin DNA from hippocampal neurons of rats, and to screen out five putative genes associated with the learning and memory functions. The promoter regions of the calcium/calmodulin-dependent protein kinase II alpha and glutamate receptor-2 genes were amplified by PCR from DNA products immunoprecipitated by amyloid precursor protein intracellular domain. An electrophoretic mobility shift assay and western blot analysis suggested that the promoter regions of these two genes associated with learning and memory were bound by amyloid precursor protein intracellular domain (in complex form). Our experimental findings indicate that the amyloid precursor protein intracellular domain is involved in the transcriptional regulation of learning- and memory-associated genes in hippocampal neurons. These data may provide new insights into the molecular mechanism underlying the symptoms of progressive memory loss in Alzheimer's disease.展开更多
We have constructed a retroviral vector mediated mammalian cell expression system of the capsid precursor protein of foot-and-mouth disease virus(FMDV).The recombinant retroviral vector pBABEpuro-P1-2A-EGFP was constr...We have constructed a retroviral vector mediated mammalian cell expression system of the capsid precursor protein of foot-and-mouth disease virus(FMDV).The recombinant retroviral vector pBABEpuro-P1-2A-EGFP was constructed by sequentially inserting capsid precursor protein gene(P1) of FMDV and enhanced green fluorescent protein gene(EGFP) into pBABEpuro.The recombinant retroviral vector and the pVSV-G plasmid were co-transfected into packaging cells(GP2-293) by liposomemediated transduction to produce the pseudovirus.The pseudovirus was used to infect BHK-21 cells and resistant cells were screened with puromycin.Green fluorescent proteins were observed by fluorescence microscopy and expression of the capsid precursor protein gene of FMDV was detected by indirect immunofluorescence.The recombinant retroviral vector pBABEpuro-P1-2A-EGFP was constructed successfully.The capsid precursor protein of FMDV and green fluorescent protein were expressed in BHK-21 cells.The mammalian cell expression system for the capsid precursor protein of FMDV has been constructed successfully,which lays the foundation of development of a FMDV subunit vaccine.展开更多
Pharmacological studies reveal APP and Aβ have interactions with glutamate and calcium, cytokines, copper/zinc chelators, secretases and presenilins, nicotinic receptors, acetycholinesterase, neurotrophins, non-stero...Pharmacological studies reveal APP and Aβ have interactions with glutamate and calcium, cytokines, copper/zinc chelators, secretases and presenilins, nicotinic receptors, acetycholinesterase, neurotrophins, non-steroidal anti-inflame-matory drugs, monoclonal antibodies to Aβ, protease inhibitors, oestrogen, homocysteine, immediate early genes such as c-fos or c-jun and cholesterol. These functional and pharmacological observations highlight the need for greater understanding of APP and Aβ in brain function and have implications for clinical trials.展开更多
The amyloid precursor protein gene (APP) and its derivative peptides have important functions in the central nervous system. APP and Aβ fulfil criteria as neuractive peptides: presence, release and identity of action...The amyloid precursor protein gene (APP) and its derivative peptides have important functions in the central nervous system. APP and Aβ fulfil criteria as neuractive peptides: presence, release and identity of action. Aβ is a peptide of 1 - 43 amino acids in length, derived from APP and the major component of the core of neuritic plaques found in Alzheimer’s disease. Analysis of the cDNA of Aβ revealed its origins from the larger precursor protein. There are at least four types of mRNA generated by alternative splicing of exons 7 and 8. Exon 7 encodes a 57 amino acid sequence found in the extracellular domain with major homology to the Kunitz-type of serine protease inhibitors. APP is cleaved by three secretases known as α, β, and γ secretase which act on APP at different sites producing various fragments of differing amino acid length. The γ secretase is a macromolecular enzyme complex composed of presenilin 1, 2 and other molecular constitutents essential for its function.展开更多
In vitro studies suggest Amyloid Precursor Protein Gene (APP) is involved in interaction with the extracellular matrix, neurite growth, adhesion, development, synaptic function, platelet function, and interaction with...In vitro studies suggest Amyloid Precursor Protein Gene (APP) is involved in interaction with the extracellular matrix, neurite growth, adhesion, development, synaptic function, platelet function, and interaction with GTP binding proteins. In vivo experiments show a role in embryonic development, response to cerebral excitotoxicity and gliosis, response to brain injury including ischaemia, hypothalamic function, locomotor function, learning and memory. In vitro observations indicate Aβ has a role in amyloid formation, excitotoxic neuronal injury, tachykinin interaction, endothelial vasoconstrictor response, calcium and oxidative stress, free radical interaction, cell membrane fluidity, apoptosis, astrocyte stimulation, and microglial interaction. Other studies suggest important roles for Aβ oligomers in synaptic function and as an antimicrobial peptide. In vivo investigations show involvement in memory function, the blood brain barrier, and tachykinin response to cerebral injury.展开更多
BACKGROUND: The pharmacological actions of Panax notoginseng saponins (PNS) lie in removing free radicals, anti-inflammation and anti-oxygenation. It can also improve memory and behavior in rat models of Alzheime...BACKGROUND: The pharmacological actions of Panax notoginseng saponins (PNS) lie in removing free radicals, anti-inflammation and anti-oxygenation. It can also improve memory and behavior in rat models of Alzheimer's disease. OBJECTIVE: Using the Morris water maze, immunohistochemistry, real-time PCR and RT-PCR, this study aimed to measure improvement in spatial learning, memory, expression of amyloid precursor protein (App) and β -amyloid (A β ), to investigate the mechanism of action of PNS in the treatment of AD in the senescence accelerated mouse-prone 8 (SAMP8) and compare the effects with huperzine A. DESIGN, TIME AND SETTING: A completely randomized grouping design, controlled animal experiment was performed in the Center for Research & Development of New Drugs, Guangxi Traditional Chinese Medical University from July 2005 to April 2007. MATERIALS: Sixty male SAMP8 mice, aged 3 months, purchased from Tianjin Chinese Traditional Medical University of China, were divided into four groups: PNS high-dosage group, PNS low-dosage group, huperzine A group and control group. PNS was provided by Weihe Pharmaceutical Co., Ltd. (batch No.: Z53021485, Yuxi, Yunan Province, China). Huperzine A was provided by Zhenyuan Pharmaceutical Co., Ltd. (batch No.: 20040801, Zhejiang, China). METHODS: The high-dosage group and low-dosage group were treated with 93.50 and 23.38 mg/kg PNS respectively per day and the huperzine A group was treated with 0.038 6 mg/kg huperzine A per day, all by intragastric administration, for 8 consecutive weeks. The same volume of double distilled water was given to the control group. MAIN OUTCOME MEASURES: After drug administration, learning and memory abilities were assessed by place navigation and spatial probe tests. The recording indices consisted of escape latency (time-to-platform), and the percentage of swimming time spent in each quadrant. The number of A β 1-40, A β 1-42 and App immunopositive neurons in the brains of SAMP8 mice was analyzed by immunohistochemistry. The mRNA content ofApp, tau, acetylcholinesterase, and synaptophysin (Syp) was tested by real time PCR and RT-PCR. RESULTS: The PCR results show that PNS can downregulate the expression of the App gene and upregulate the expression of the Syp gene in the parietal cortex and hippocampus of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than those of the PNS low-dosage group and the huperzine A group (P 〈 0.05). The results of the Morris water maze and immunohistochemistry indicated that PNS can improve the capacity for spatial learning and memory in SAMP8 mice, and reduce the content of A β 1-40, A β 1-42 and expression of App in the brains of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than that of the PNS low-dosage group and the huperzine A group (P 〈 0.05). CONCLUSION: These results support the hypothesis that PNS plays a therapeutic and protective role on the pathological lesions and learning dysfunction of Alzheimer's disease. The therapeutic effects of PNS for Alzheimer's disease are possibly achieved through downregulating the expression of the App gene and upregulating the expression of the Syp gene. The therapeutic effects of PNS are dose-dependent and are greater than the effect of huperzine A.展开更多
Objective To investigate the impact of sub-chronic Aluminium-maltolate [Al(mal)s] exposure on the catabolism of amyloid precursor protein (APP) in rats. Methods Forty adult male Sprague-Dawley (SD) rats were ran...Objective To investigate the impact of sub-chronic Aluminium-maltolate [Al(mal)s] exposure on the catabolism of amyloid precursor protein (APP) in rats. Methods Forty adult male Sprague-Dawley (SD) rats were randomly divided into five groups: the control group, the maltolate group (7.56 mg/kg BW), and the Al(mal)s groups (0.27, 0.54, and 1.08 mg/kg BW, respectively). Control rats were administered with 0.9% normal saline through intraperitoneal (i.p.) injection. Maltolate and Al(mal)s were administered to the rats also through i.p. injections. Administration was conducted daily for two months. Rat neural behavior was examined using open field tests (OFT). And the protein expressions and their mRNAs transcription related with APP catabolism were studied using enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR). Results The expressions of APP, 13-site APP cleaving enzyme 1 (BACEI) and presenilin-1 (PSi) proteins and their mRNAs transcription increased gradually with the increase of Al(mal)3 doses (P〈0.05). The enzyme activity of BACEI in the 0.54 and 1.08 mg/kg Al(mal)s groups increased significantly (P〈0.05). The expression of 8-amyloid protein (AS) 1-40 gradually decreased while the protein expression of A81-42 increased gradually with the increase of Al(mal)s doses (P〈0.05). Conclusion Result from our study suggested that one of the possible mechanisms that Al(mal)s can cause neurotoxicity is that Al(mal)s can increase the generation of A81-42 by facilitating the expressions of APP, β-, and γ-secretase.展开更多
VP1, a capsid protein of swine vesicular disease virus, was cloned from the SVDV HK/70 strain and inserted into retroviral vector pBABE puro, and expressed in PK15 cells by an retroviral expression system. The ability...VP1, a capsid protein of swine vesicular disease virus, was cloned from the SVDV HK/70 strain and inserted into retroviral vector pBABE puro, and expressed in PK15 cells by an retroviral expression system. The ability of the VP1 protein to induce an immune response was then evaluated in guinea pigs. Western blot and ELISA results indicated that the VP1 protein can be recognized by SVDV positive serum, Furthermore, anti-SVDV specific antibodies and lymphocyte proliferation were elicited and increased by VP1 protein after vaccination. These results encourage further work towards the development of a vaccine against SVDV infection.展开更多
BACKGROUND: Yishendaluo decoction reduces production of inflammatory mediators, relieves damage due to inflammatory reactions, and improves neural functions during experimental autoimmune encephalomyelitis. OBJECTIVE...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.展开更多
AIM: To develop and optimize cDNA representationaldifference analysis (cDNA RDA) method and to identify andclone garlic up-regulated genes in human gastric cancer(HGC) cells.METHODS: We performed cDNA RDA method by us...AIM: To develop and optimize cDNA representationaldifference analysis (cDNA RDA) method and to identify andclone garlic up-regulated genes in human gastric cancer(HGC) cells.METHODS: We performed cDNA RDA method by usingabundant double-stranded cDNA messages provided by twoself-constructed cDNA libraries (Allitridi-trested and paternalHGC cell line BGC823 cells cDNA libraries respectively).BamH Ⅰ and Xho I restriction sites harbored in the libraryvector were used to select representations. Northern andSlot blots analyses were employed to identify the obtaineddifference products.RESJLTS: Fragments released from the cDNA library vectorafter restriction endonuclease digestion acted as goodmarker indicating the appropriate digestion degree for libraryDNA. Two novel expressed sequence tags (ESTs) and arecombinant gene were obtained. Slot blots result showed a8-fold increase of gila-derived nexin/protease nexin 1 (GDN/PN1 ) gene expression level and 4-fold increase of hepatitis Bvirus x-interacting protein (XIP) mRNA level in BGC823 cellsafter Allitridi treatment for 72 h.CONCLUSION: Elevated levels of GDN/PN1 and XIP mRNAsinduced by Allitridi provide valuable molecular evidence forelucidating the garlic' s efficacies against neurodegenerativeand inflammatory diseases. Isolation of a recombinant geneand two novel ESTs further show cDNA RDA based on cDNAlibraries to be a powerful method with high specificity andreproducibility in cloning differentially expressed genes.展开更多
There are few studies on the membrane protein Ankfyl. We have found Ankfyl is specifically expressed in neural stem/precursor cells during early development in mice (murine). To further explore Ankfyl function in ne...There are few studies on the membrane protein Ankfyl. We have found Ankfyl is specifically expressed in neural stem/precursor cells during early development in mice (murine). To further explore Ankfyl function in neural development, we developed a gene knockout mouse with a mixed Balb/C and C57/BL6 genetic background. Using immunofluorescence and in situ hybridization, neural defects were absent in mixed genetic Ankfyl null mice during development and in adults up to 2 months old. However, Ankfyl gene knockout mice with a pure genetic background were found to be lethal in the C57/BL6 inbred mice embryos, even after seven generations of backcrossing. Polymerase chain reaction confirmed homozygotes were unattainable as early as embryonic day 11.5. We conclude that Ankfyl protein is dispensable in neural stem/precursor ceils, but could be critical for early embryonic murine development, depending on the genetic background.展开更多
The capsid protein precursor (P1), which plays a major role for the generation of polypeptides of swine vesicular disease virus (SVDV), was cloned from SVDV HK/70 strain into the retroviral vector pBABE puro and e...The capsid protein precursor (P1), which plays a major role for the generation of polypeptides of swine vesicular disease virus (SVDV), was cloned from SVDV HK/70 strain into the retroviral vector pBABE puro and expressed in the mammalian cell line PK15 through the retroviral expression system. The activity of recombinant protein to induce immune response was evaluated in guinea pigs. IFA and Western Blot were used to detect the recombinant protein expression. The results showed that the recombinant protein could be recognized by SVDV positive serum, and animal test showed SVDV-specific antibodies. All of those results indicate that a retroviral-based vaccine carrying the capsid protein precursor (P1) of SVD is able to be expressed in the eukaryotic cell and elicites strong SVDV-specific immune responses in guinea pigs.展开更多
Alzheimer’s disease (AD) is a common neurodegenerative disease, its main clinical symptoms are the progressive decline of cognitive and memory functions. Enriched Environment (EE) achieves the goal of improving brain...Alzheimer’s disease (AD) is a common neurodegenerative disease, its main clinical symptoms are the progressive decline of cognitive and memory functions. Enriched Environment (EE) achieves the goal of improving brain cognitive reserve by enhancing the multi-directional stimulation on movement, sensory and cognitive systems of animals. And EE can regulate the levels of various trophic factors in the brain, promote synaptic regeneration and enhance neural plasticity to reduce the loss of neurons induced by inflammation. At present, there is still no effective treatment for AD and the clinical intervention drug is expensive. So it is essential to actively explore non-drug treatment. This review will explain the effects of EE on learning ability, memory ability and mental behavior in AD, and provide a new direction for the treatment and rehabilitation of AD.展开更多
Objective: To observe the effect of Huannao Yicong Prescription (还脑益聪方, HNYC, a Chinese medical compound) extract on β-amyloid precursor protein (APP) metabolic signal transductionrelated protein kinase C ...Objective: To observe the effect of Huannao Yicong Prescription (还脑益聪方, HNYC, a Chinese medical compound) extract on β-amyloid precursor protein (APP) metabolic signal transductionrelated protein kinase C (PKC), tyrosine amyloid protein kinase (TrKA), and glycogen synthase kinase-3 (GSK-3) in brain tissue of transgenic mouse dementia model induced by APP. Methods: Sixty dementia model transgenic 3-month-old mice induced by APP695V7171 were randomly allocated in four groups: the model group (A), the Donepezil (0.65×10^-3 g.kg-1.d-1)-treated group (B), and the two HNYC-treated groups (C and D) with high dosage (2.8 g.kg^-1.d^-1) and low dosage (1.4 g.kg^-1.d^-1) of HNYC extract, respectively, 15 mice in each group. Besides, a normal control group was set up with 15 C57BL/6J mice with the same age and genetic background as the model mice. The drugs for treatment were administered once a day by dissolving in equal-volume distilled water through gastric infusion, continued for 6 months, to mice in group A and to normal control group equal-volume distilled water was administered instead. Spatial learning and memory capacity of mice were observed by Morris water maze; their one-time escape response memory capacity was tested by diving platform; and changes of PKC, TrkA, and GSK-3 levels in hippocampus and cortex of brain were detected by Western blotting. Results: HNYC extract showed significant effects on increasing the time of model mice for swimming through the flat roof and the swimming time and path in the fourth quadrant (P〈0.05 or P〈0.01). Diving platform test showed that the latent times in Groups B and C were longer than that in Group A significantly (P〈0.05 and P〈0.01). Compared with the normal control group, PKC and TrkA protein expression levels in hippocampus and cortex of model mice's brain lowered significantly (P〈0.01), while GSK-3 protein expression increased significantly (P〈0.01); compared with Group A (the model group), hippocampal and cortical levels of PKC protein expression in the intervened groups (B-D) as well as those of TrkA in Group C were higher (P〈0.01 or P〈0.05), while hippocampal levels of GSK-3 in intervened groups were lower (P〈0.01). Conclusion: HNYC extract could obviously increase the protein expressions of PKC and TrkA and decrease the expression of GSK-3 protein in brain tissue of transgenetic mice model of dementia, and regulate APP metabolic signal transduction path, and thus to suppress the production of A β, which is one of the dominant mechanisms for improving learning/memory capacity of dementia model animals.展开更多
基金funded by the National Natural Science Foundation of China,No.81671268(to HQ)partially supported by a grant from the Ministry of Science and Technology of China,No.2013YQ03059514(to HQ)a grant from Key Laboratory for Neurodegenerative Disease of Ministry of Education of China,No.2015SJBX05(to HQ),2015SJZS01(to HQ)
文摘Alzheimer's disease is pathologically defined by accumulation of extracellular amyloid-β(Aβ). Approximately 25 mutations in β-amyloid precursor protein(APP) are pathogenic and cause autosomal dominant Alzheimer's disease. To date, the mechanism underlying the effect of APP mutation on Aβ generation is unclear. Therefore, investigating the mechanism of APP mutation on Alzheimer's disease may help understanding of disease pathogenesis. Thus, APP mutations(A673T, A673 V, E682 K, E693 G, and E693Q) were transiently co-transfected into human embryonic kidney cells. Western blot assay was used to detect expression levels of APP, beta-secretase 1, and presenilin 1 in cells. Enzyme-linked immunosorbent assay was performed to determine Aβ_(1–40) and Aβ_(1–42) levels. Liquid chromatography-tandem mass chromatography was used to examine VVIAT, FLF, ITL, VIV, IAT, VIT, TVI, and VVIA peptide levels. Immunofluorescence staining was performed to measure APP and early endosome antigen 1 immunoreactivity. Our results show that the protective A673 T mutation decreases Aβ_(42)/Aβ_(40) rate by downregulating IAT and upregulating VVIA levels. Pathogenic A673 V, E682 K, and E693 Q mutations promote Aβ_(42)/Aβ_(40) rate by increasing levels of CTF99, Aβ_(42), Aβ_(40), and IAT, and decreasing VVIA levels. Pathogenic E693 G mutation shows no significant change in Aβ_(42)/Aβ_(40) ratio because of inhibition of γ-secretase activity. APP mutations can change location from the cell surface to early endosomes. Our findings confirm that certain APP mutations accelerate Aβ generation by affecting the long Aβ cleavage pathway and increasing Aβ_(42/40) rate, thereby resulting in Alzheimer's disease.
基金Supported by:Guangxi Scientific Research and Technological Development Program,No.0630002-2ADoctoral Research and Innovation Program of Guangxi Graduate Education,No, 2007105981007D10
文摘BACKGROUND: During onset and development of Alzheimer's disease, β-amyloid (Aβ) precursor protein (APP), β-site amyloid precursor protein cleaving enzyme (BACE), and β-amyloid are key genes and proteins in the Aβ pathway, and over-expression of these genes can lead to Aβ deposit/on in the brain. OBJECTIVE: To observe the influence of Longyanshen polysaccharides on expression of BACE, APP, and Aβ in the senescence-accelerated mouse prone/8 (SAMP8) brain, and to compare these effects with huperzine A treatment. DESIGN, TIME AND SETTING: A randomized, controlled, neurobiochemical experiment was performed at the Department of Pharmacology and Scientific Experimental Center of Guangxi Medical University from September 2005 to January 2008. MATERIALS: Longyanshen polysaccharfdes powder was extracted from the dried slices of the medicinal plant Longyanshen. The active component, Longyanshen polysaccharides, was provided by the Department of Pharmacology, Guangxi Medical University; huperzine A was purchased from Yuzhong Drug Manufactory, China. METHODS: Healthy SAMP8 mice were used to establish a model of Alzheimer's disease. A total of 50 SAMP8 mice were randomly assigned to 5 groups (n = 10): SAMP8, huperzine A, low-, middle-, and high-dose polysaccharides. In addition, 10 senescence-accelerated mouse resistant 1 (SAMR1) mice were selected as normal controls. SAMP8 and SAMR1 mice were administered 30 mL/kg normal saline; the huperzine A group was administered 0.02 mg/kg huperzine A; the low-, middle-, and high-dose polysaccharides groups were respectively administered 45, 90, and 180 mg/kg Longyanshen polysaccharides. Each group was treated by intragastric administration, once per day, for 50 consecutive days. MAIN OUTCOME MEASURES: One hour after the final administration, immunohistochemical analysis was used to determine Aβ expression in the cortex and hippocampus of SAMP8 mice. Reverse-transcription polymerase chain reaction was used to determine mRNA levels of BACE and APP in SAMP8 brain tissue. RESULTS: Compared with the SAMR1 group, Aβ expression in the cerebral cortex and hippocampus, as well as expression of BACE, APP mRNA in the brain was significantly increased in the SAMP8 group (P 〈 0.05-0.01). Compared with the SAMP8 group, Aβ expression, as well as BACE and APP mRNA expression, were significantly decreased in the cerebral cortex and hippocampus of huperzine A and low-, middle-, and high-dose polysaccharides groups (P 〈 0.05-0.01). In particular, the effect of high-dose polysaccharides was the most significant (P 〈 0.05-0.01 ). CONCLUSION: Longyanshen polysaccharides reduced or inhibited over-expression of BACE, APP, and Aβ in SAMP8 mice in a dose-dependent manner, and the effect was not worse than huperzine A.
基金the National Natural Science Foundation of China,No.30900773the National University Basic Research Foundation of China,No.2010QZZD022
文摘Previous studies have reported that non-human primates and rodents exposed to lead during brain development may become dependent on the deposition of pre-determined β-amyloid protein (Aβ),and exhibit upregulation of β-site amyloid precursor protein expression in old age.However,further evidence is required to elucidate the precise relationship and molecular mechanisms underlying the effects of early lead exposure on excessive Aβ production in adult mammals.The present study investigated the effects of lead exposure on expression of β-amyloid precursor protein cleavage enzyme-1 (BACE-1) in the rat retina and the production of Aβ in early development,using the retina as a window for studying Alzheimer's disease.Adult rats were intraocularly injected with different doses of lead acetate (10μmol/L,100μmol/L,1 mmol/L,10 mmol/L and 100 mmol/L).The results revealed that retinal lead concentration,BACE-1 and its cleavage products β-C-terminal fragment and retina Aβ1-40 were all significantly increased in almost all of the lead exposure groups 48 hours later in a dose-dependent manner.The only exception was the 10μmol/L group.The distribution of BACE-1 in the retina did not exhibit obvious changes,and no distinctive increase in the activation of retinal microglia was apparent.Similarly,retinal synaptophysin expression did not exhibit any clear changes.These data suggest that lead exposure can result in the upregulation of retinal neuron BACE-1 expression in the early period of development and further increase the overproduction of Aβ1-40 in the retina.Our results provided novel insight into the molecular mechanisms underlying environmentally-induced Alzheimer's disease.
基金supported by the Natural Science Foundation of Guangdong Province,China,No.8151051501000004
文摘In this study, we employed chromatin immunoprecipitation, a useful method for studying the locations of transcription factors bound to specific DNA regions in specific cells, to investigate amyloid precursor protein intracellular domain binding sites in chromatin DNA from hippocampal neurons of rats, and to screen out five putative genes associated with the learning and memory functions. The promoter regions of the calcium/calmodulin-dependent protein kinase II alpha and glutamate receptor-2 genes were amplified by PCR from DNA products immunoprecipitated by amyloid precursor protein intracellular domain. An electrophoretic mobility shift assay and western blot analysis suggested that the promoter regions of these two genes associated with learning and memory were bound by amyloid precursor protein intracellular domain (in complex form). Our experimental findings indicate that the amyloid precursor protein intracellular domain is involved in the transcriptional regulation of learning- and memory-associated genes in hippocampal neurons. These data may provide new insights into the molecular mechanism underlying the symptoms of progressive memory loss in Alzheimer's disease.
基金supported by the National Programs for High Technology Research and Development of China (2006AA10A204)the Gansu Key Technologies R&D Program(ZGS-052-A41-0006-03)the Programs for Director Fund of Lanzhou Veterinary Research Institute
文摘We have constructed a retroviral vector mediated mammalian cell expression system of the capsid precursor protein of foot-and-mouth disease virus(FMDV).The recombinant retroviral vector pBABEpuro-P1-2A-EGFP was constructed by sequentially inserting capsid precursor protein gene(P1) of FMDV and enhanced green fluorescent protein gene(EGFP) into pBABEpuro.The recombinant retroviral vector and the pVSV-G plasmid were co-transfected into packaging cells(GP2-293) by liposomemediated transduction to produce the pseudovirus.The pseudovirus was used to infect BHK-21 cells and resistant cells were screened with puromycin.Green fluorescent proteins were observed by fluorescence microscopy and expression of the capsid precursor protein gene of FMDV was detected by indirect immunofluorescence.The recombinant retroviral vector pBABEpuro-P1-2A-EGFP was constructed successfully.The capsid precursor protein of FMDV and green fluorescent protein were expressed in BHK-21 cells.The mammalian cell expression system for the capsid precursor protein of FMDV has been constructed successfully,which lays the foundation of development of a FMDV subunit vaccine.
文摘Pharmacological studies reveal APP and Aβ have interactions with glutamate and calcium, cytokines, copper/zinc chelators, secretases and presenilins, nicotinic receptors, acetycholinesterase, neurotrophins, non-steroidal anti-inflame-matory drugs, monoclonal antibodies to Aβ, protease inhibitors, oestrogen, homocysteine, immediate early genes such as c-fos or c-jun and cholesterol. These functional and pharmacological observations highlight the need for greater understanding of APP and Aβ in brain function and have implications for clinical trials.
文摘The amyloid precursor protein gene (APP) and its derivative peptides have important functions in the central nervous system. APP and Aβ fulfil criteria as neuractive peptides: presence, release and identity of action. Aβ is a peptide of 1 - 43 amino acids in length, derived from APP and the major component of the core of neuritic plaques found in Alzheimer’s disease. Analysis of the cDNA of Aβ revealed its origins from the larger precursor protein. There are at least four types of mRNA generated by alternative splicing of exons 7 and 8. Exon 7 encodes a 57 amino acid sequence found in the extracellular domain with major homology to the Kunitz-type of serine protease inhibitors. APP is cleaved by three secretases known as α, β, and γ secretase which act on APP at different sites producing various fragments of differing amino acid length. The γ secretase is a macromolecular enzyme complex composed of presenilin 1, 2 and other molecular constitutents essential for its function.
文摘In vitro studies suggest Amyloid Precursor Protein Gene (APP) is involved in interaction with the extracellular matrix, neurite growth, adhesion, development, synaptic function, platelet function, and interaction with GTP binding proteins. In vivo experiments show a role in embryonic development, response to cerebral excitotoxicity and gliosis, response to brain injury including ischaemia, hypothalamic function, locomotor function, learning and memory. In vitro observations indicate Aβ has a role in amyloid formation, excitotoxic neuronal injury, tachykinin interaction, endothelial vasoconstrictor response, calcium and oxidative stress, free radical interaction, cell membrane fluidity, apoptosis, astrocyte stimulation, and microglial interaction. Other studies suggest important roles for Aβ oligomers in synaptic function and as an antimicrobial peptide. In vivo investigations show involvement in memory function, the blood brain barrier, and tachykinin response to cerebral injury.
基金the National Natural Science Foundation of China, No: 30560189
文摘BACKGROUND: The pharmacological actions of Panax notoginseng saponins (PNS) lie in removing free radicals, anti-inflammation and anti-oxygenation. It can also improve memory and behavior in rat models of Alzheimer's disease. OBJECTIVE: Using the Morris water maze, immunohistochemistry, real-time PCR and RT-PCR, this study aimed to measure improvement in spatial learning, memory, expression of amyloid precursor protein (App) and β -amyloid (A β ), to investigate the mechanism of action of PNS in the treatment of AD in the senescence accelerated mouse-prone 8 (SAMP8) and compare the effects with huperzine A. DESIGN, TIME AND SETTING: A completely randomized grouping design, controlled animal experiment was performed in the Center for Research & Development of New Drugs, Guangxi Traditional Chinese Medical University from July 2005 to April 2007. MATERIALS: Sixty male SAMP8 mice, aged 3 months, purchased from Tianjin Chinese Traditional Medical University of China, were divided into four groups: PNS high-dosage group, PNS low-dosage group, huperzine A group and control group. PNS was provided by Weihe Pharmaceutical Co., Ltd. (batch No.: Z53021485, Yuxi, Yunan Province, China). Huperzine A was provided by Zhenyuan Pharmaceutical Co., Ltd. (batch No.: 20040801, Zhejiang, China). METHODS: The high-dosage group and low-dosage group were treated with 93.50 and 23.38 mg/kg PNS respectively per day and the huperzine A group was treated with 0.038 6 mg/kg huperzine A per day, all by intragastric administration, for 8 consecutive weeks. The same volume of double distilled water was given to the control group. MAIN OUTCOME MEASURES: After drug administration, learning and memory abilities were assessed by place navigation and spatial probe tests. The recording indices consisted of escape latency (time-to-platform), and the percentage of swimming time spent in each quadrant. The number of A β 1-40, A β 1-42 and App immunopositive neurons in the brains of SAMP8 mice was analyzed by immunohistochemistry. The mRNA content ofApp, tau, acetylcholinesterase, and synaptophysin (Syp) was tested by real time PCR and RT-PCR. RESULTS: The PCR results show that PNS can downregulate the expression of the App gene and upregulate the expression of the Syp gene in the parietal cortex and hippocampus of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than those of the PNS low-dosage group and the huperzine A group (P 〈 0.05). The results of the Morris water maze and immunohistochemistry indicated that PNS can improve the capacity for spatial learning and memory in SAMP8 mice, and reduce the content of A β 1-40, A β 1-42 and expression of App in the brains of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than that of the PNS low-dosage group and the huperzine A group (P 〈 0.05). CONCLUSION: These results support the hypothesis that PNS plays a therapeutic and protective role on the pathological lesions and learning dysfunction of Alzheimer's disease. The therapeutic effects of PNS for Alzheimer's disease are possibly achieved through downregulating the expression of the App gene and upregulating the expression of the Syp gene. The therapeutic effects of PNS are dose-dependent and are greater than the effect of huperzine A.
基金supported by the National Natural Science Foundation of China (30972512)the Graduate Innovation Fund of Academic Degree Committee Office of the Shanxi Provincial Government (20093014)+1 种基金Doctor Start-up Fund from Shanxi Medical University (B03201209)the College Students Innovation Fund of Shanxi Medical University (2010-25)
文摘Objective To investigate the impact of sub-chronic Aluminium-maltolate [Al(mal)s] exposure on the catabolism of amyloid precursor protein (APP) in rats. Methods Forty adult male Sprague-Dawley (SD) rats were randomly divided into five groups: the control group, the maltolate group (7.56 mg/kg BW), and the Al(mal)s groups (0.27, 0.54, and 1.08 mg/kg BW, respectively). Control rats were administered with 0.9% normal saline through intraperitoneal (i.p.) injection. Maltolate and Al(mal)s were administered to the rats also through i.p. injections. Administration was conducted daily for two months. Rat neural behavior was examined using open field tests (OFT). And the protein expressions and their mRNAs transcription related with APP catabolism were studied using enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR). Results The expressions of APP, 13-site APP cleaving enzyme 1 (BACEI) and presenilin-1 (PSi) proteins and their mRNAs transcription increased gradually with the increase of Al(mal)3 doses (P〈0.05). The enzyme activity of BACEI in the 0.54 and 1.08 mg/kg Al(mal)s groups increased significantly (P〈0.05). The expression of 8-amyloid protein (AS) 1-40 gradually decreased while the protein expression of A81-42 increased gradually with the increase of Al(mal)s doses (P〈0.05). Conclusion Result from our study suggested that one of the possible mechanisms that Al(mal)s can cause neurotoxicity is that Al(mal)s can increase the generation of A81-42 by facilitating the expressions of APP, β-, and γ-secretase.
文摘VP1, a capsid protein of swine vesicular disease virus, was cloned from the SVDV HK/70 strain and inserted into retroviral vector pBABE puro, and expressed in PK15 cells by an retroviral expression system. The ability of the VP1 protein to induce an immune response was then evaluated in guinea pigs. Western blot and ELISA results indicated that the VP1 protein can be recognized by SVDV positive serum, Furthermore, anti-SVDV specific antibodies and lymphocyte proliferation were elicited and increased by VP1 protein after vaccination. These results encourage further work towards the development of a vaccine against SVDV infection.
基金the National Natural Science Foundation of China,No.30672692
文摘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.
基金the Natural Scientific Foundation of China (NSFC3962526)National High-Technology Project-863 (102-10-01-04)
文摘AIM: To develop and optimize cDNA representationaldifference analysis (cDNA RDA) method and to identify andclone garlic up-regulated genes in human gastric cancer(HGC) cells.METHODS: We performed cDNA RDA method by usingabundant double-stranded cDNA messages provided by twoself-constructed cDNA libraries (Allitridi-trested and paternalHGC cell line BGC823 cells cDNA libraries respectively).BamH Ⅰ and Xho I restriction sites harbored in the libraryvector were used to select representations. Northern andSlot blots analyses were employed to identify the obtaineddifference products.RESJLTS: Fragments released from the cDNA library vectorafter restriction endonuclease digestion acted as goodmarker indicating the appropriate digestion degree for libraryDNA. Two novel expressed sequence tags (ESTs) and arecombinant gene were obtained. Slot blots result showed a8-fold increase of gila-derived nexin/protease nexin 1 (GDN/PN1 ) gene expression level and 4-fold increase of hepatitis Bvirus x-interacting protein (XIP) mRNA level in BGC823 cellsafter Allitridi treatment for 72 h.CONCLUSION: Elevated levels of GDN/PN1 and XIP mRNAsinduced by Allitridi provide valuable molecular evidence forelucidating the garlic' s efficacies against neurodegenerativeand inflammatory diseases. Isolation of a recombinant geneand two novel ESTs further show cDNA RDA based on cDNAlibraries to be a powerful method with high specificity andreproducibility in cloning differentially expressed genes.
基金Dr.Hui Fu was supported by the National Natural Science Foundation of China,No.81371338by Open Research Fund Program of Hubei-MOST KLOS & KLOBMEDr.Zu-neng Lu was supported by grants from Health and Family Planning Commission of Hubei Province scientific research project,No.WJ2015MA007
文摘There are few studies on the membrane protein Ankfyl. We have found Ankfyl is specifically expressed in neural stem/precursor cells during early development in mice (murine). To further explore Ankfyl function in neural development, we developed a gene knockout mouse with a mixed Balb/C and C57/BL6 genetic background. Using immunofluorescence and in situ hybridization, neural defects were absent in mixed genetic Ankfyl null mice during development and in adults up to 2 months old. However, Ankfyl gene knockout mice with a pure genetic background were found to be lethal in the C57/BL6 inbred mice embryos, even after seven generations of backcrossing. Polymerase chain reaction confirmed homozygotes were unattainable as early as embryonic day 11.5. We conclude that Ankfyl protein is dispensable in neural stem/precursor ceils, but could be critical for early embryonic murine development, depending on the genetic background.
基金Supported by Key Technology R&D Programme (2006BAD06A03)
文摘The capsid protein precursor (P1), which plays a major role for the generation of polypeptides of swine vesicular disease virus (SVDV), was cloned from SVDV HK/70 strain into the retroviral vector pBABE puro and expressed in the mammalian cell line PK15 through the retroviral expression system. The activity of recombinant protein to induce immune response was evaluated in guinea pigs. IFA and Western Blot were used to detect the recombinant protein expression. The results showed that the recombinant protein could be recognized by SVDV positive serum, and animal test showed SVDV-specific antibodies. All of those results indicate that a retroviral-based vaccine carrying the capsid protein precursor (P1) of SVD is able to be expressed in the eukaryotic cell and elicites strong SVDV-specific immune responses in guinea pigs.
文摘Alzheimer’s disease (AD) is a common neurodegenerative disease, its main clinical symptoms are the progressive decline of cognitive and memory functions. Enriched Environment (EE) achieves the goal of improving brain cognitive reserve by enhancing the multi-directional stimulation on movement, sensory and cognitive systems of animals. And EE can regulate the levels of various trophic factors in the brain, promote synaptic regeneration and enhance neural plasticity to reduce the loss of neurons induced by inflammation. At present, there is still no effective treatment for AD and the clinical intervention drug is expensive. So it is essential to actively explore non-drug treatment. This review will explain the effects of EE on learning ability, memory ability and mental behavior in AD, and provide a new direction for the treatment and rehabilitation of AD.
基金Supported by the National Natural Science Foundation of China(No.30873338)the Major New Drug Projects of the Ministry of Science and Technology of P.R China(No 2009ZX09103-391)
文摘Objective: To observe the effect of Huannao Yicong Prescription (还脑益聪方, HNYC, a Chinese medical compound) extract on β-amyloid precursor protein (APP) metabolic signal transductionrelated protein kinase C (PKC), tyrosine amyloid protein kinase (TrKA), and glycogen synthase kinase-3 (GSK-3) in brain tissue of transgenic mouse dementia model induced by APP. Methods: Sixty dementia model transgenic 3-month-old mice induced by APP695V7171 were randomly allocated in four groups: the model group (A), the Donepezil (0.65×10^-3 g.kg-1.d-1)-treated group (B), and the two HNYC-treated groups (C and D) with high dosage (2.8 g.kg^-1.d^-1) and low dosage (1.4 g.kg^-1.d^-1) of HNYC extract, respectively, 15 mice in each group. Besides, a normal control group was set up with 15 C57BL/6J mice with the same age and genetic background as the model mice. The drugs for treatment were administered once a day by dissolving in equal-volume distilled water through gastric infusion, continued for 6 months, to mice in group A and to normal control group equal-volume distilled water was administered instead. Spatial learning and memory capacity of mice were observed by Morris water maze; their one-time escape response memory capacity was tested by diving platform; and changes of PKC, TrkA, and GSK-3 levels in hippocampus and cortex of brain were detected by Western blotting. Results: HNYC extract showed significant effects on increasing the time of model mice for swimming through the flat roof and the swimming time and path in the fourth quadrant (P〈0.05 or P〈0.01). Diving platform test showed that the latent times in Groups B and C were longer than that in Group A significantly (P〈0.05 and P〈0.01). Compared with the normal control group, PKC and TrkA protein expression levels in hippocampus and cortex of model mice's brain lowered significantly (P〈0.01), while GSK-3 protein expression increased significantly (P〈0.01); compared with Group A (the model group), hippocampal and cortical levels of PKC protein expression in the intervened groups (B-D) as well as those of TrkA in Group C were higher (P〈0.01 or P〈0.05), while hippocampal levels of GSK-3 in intervened groups were lower (P〈0.01). Conclusion: HNYC extract could obviously increase the protein expressions of PKC and TrkA and decrease the expression of GSK-3 protein in brain tissue of transgenetic mice model of dementia, and regulate APP metabolic signal transduction path, and thus to suppress the production of A β, which is one of the dominant mechanisms for improving learning/memory capacity of dementia model animals.