A clinical and genetic study on early-onset Alzheimer's disease associated with presenilin-1 in three Chinese families / 中华老年医学杂志

Objective:To investigate the clinical and genetic features of early-onset Alzheimer's disease(EOAD)and the characteristics of pathogenic mutations in probands and their families.Methods:Clinical and genetic features of three EOAD probands and their family members China were analyzed and summarized.Peripheral blood of three probands and their relatives was collected and the genes were detected by second generation sequencing(Next Generation Sequencing, NGS). Pathogenic mutations carried by the probands were identified by whole exome sequencing and then verified by Sanger sequencing in the probands and their families.Furthermore, the clinical and genetic characteristics of EOAD were discussed.Results:The first case was familial EOAD, with the heterozygous mutation c. 851C>T(p.P284L)in exon 8 of PSEN1.The second was also a case of familial EOAD, involving the heterozygous deletion mutation c. 497_499del(p.Ile167del)in exon 6 of PSEN1.In the third proband, there was no family history and the c. 626G>A(G209E)mutation was found in exon 7 of the PSEN1 gene.All three patients had memory loss as their first symptom, accompanied by clinical manifestations of slow movement, abnormal gait, unclear speech, bladder and bowel incontinence, psychiatric and other symptoms.Conclusions:These mutations represent additional mutation types and clinical manifestations in EOAD patients.Examining the genetic characteristics of PSEN1 in EOAD may contribute to the understanding of the pathogenesis, genetic classification and clinical diagnosis of EOAD.

Effect of Modified Shuyuwan on Neuroinflammation in APP/PS1 Dementia Mice Based on Nlrp3/ASC/Caspase-1 Signaling Pathway / 中国实验方剂学杂志

Objective:To observe the effect of modified Shuyuwan in amyloid precursor protein/ presenilin 1 （APP/PS1） dementia mice on cognitive and memory impairment and to explore its mechanism. Method:The 40 APP/PS1 mice were divided into model group （given Physiological saline）， low and high-dose modified Shuyuwan （14，64 g·kg^-1）group， and donepezil group （1 mg·kg^-1） and 10 wild mice were set as the blank control group （given Physiological saline）. All of the mice were administered intragastrically for 35 days. The memory and space exploration ability of mice was detected by Morris water maze， the morphology of mouse hippocampal neurons were observed by Nissl staining. The deposition of <italic>β </italic>amyloid 1-42（A<italic>β</italic>_1-42） in mouse hippocampus was detected by immunohistochemistry， and the expression of ionized calcium-binding adapter molecule 1（Iba1）， a marker of hippocampal microglia （MG） and Nitric oxide synthase（iNOS）， a marker of actived MG， were detected by immunofluorescence. The protein expression of NLR family pyrin domain containing 3（Nlrp3）， Apoptosis-associated speck-like protein containing a Caspase-recruitment domain （ASC）， cysteine protease-1（Caspase-1）and interleukin-1 beta （IL-1<italic>β</italic>） were detected by Western blot， and the expression of IL-1<italic>β</italic>， tumor necrosis factor-<italic>α</italic>（TNF-<italic>α</italic>）and interleukin-18 （IL-18） mRNA were detected by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. Result:Compared with the blank control group， the memory and space exploration ability of the model group were significantly reduced （<italic>P</italic><0.05）， the number of hippocampal neurons decreased， the deposition of A<italic>β</italic>_1-42 increased， the markers of actived MG Iba1，iNOS increased， the protein expression of Nlrp3， ASC， Caspase-1， IL-1<italic>β</italic> increased significantly （<italic>P</italic><0.05）， and the mRNA expression of IL-1<italic>β</italic>， IL-18， and TNF-<italic>α</italic> increased significantly （<italic>P</italic><0.05）. Compared with model group， the Chinese medicine group can improve the APP/PS1 mice's space exploration ability and memory ability （<italic>P</italic><0.05）， increase the number of hippocampal neurons， reduce A<italic>β</italic>_1-42 deposition， reduce the activation of MG， and reduce the protein expression of Nlrp3， ASC， Caspase-1 and IL-1<italic>β</italic> （<italic>P</italic><0.05）， and reduced the expression of IL-1<italic>β</italic> mRNA （<italic>P</italic><0.05）. Conclusion:Modified Shuyuwan can reduce the expression of IL-1<italic>β</italic> and other inflammatory factors in the hippocampus of APP/PS1 mice by inhibiting the Nlrp3/ASC/Caspase-1 pathway， and relieve nerve inflammation and pathological injury of AD.

Investigation of a Chinese pedigree with early-onset familial Alzheimer's disease caused by presenilin 1 p.M233T mutation / 中华神经科杂志

Objective To analyze the clinical presentation and genotype of a Chinese pedigree with early-onset familial Alzheimer's disease.Methods A pedigree with early-onset familial Alzheimer's disease was recruited.The clinical data of the proband who admitted to Shengjing Hospital in March 2018 and the family members were collected.The DNA sequences of 53 dementia related genes were screened using next-generation sequencing technology in the blood sample of the proband.The point mutation discovered in the proband was also investigated in some family members.Results There were five members with Alzheimer's disease in the pedigree,including the proband,a 42 years old female.The onset age of a pedigree member was 33 years and that of the proband was 37 years.A point mutation from T to C at position 698 (M233T) in the exon 7 of presenilin 1 (PS1) gene was found in the proband and two other family members who were clinically normal.Conclusions The M233T mutation of PS1 gene can lead to early-onset familial Alzheimer's disease.This family is the first pedigree with M233T mutation of PS1 gene in China,which deserves clinical attention.

Analysis of gene and imaging on a late onset Alzheimer's pedigree concomitant with presenilin 1 mutation / 中华行为医学与脑科学杂志

Objective To analyze the clinical manifestation,imaging data and genetics mutation variants of late onset familial Alzheimer's disease concomitant with a novel mutation of presenilin 1.Methods The clinical manifestations and auxiliary examination recordings of the pedigree were analyzed.DNA was extracted from peripheral blood samples of the proband and her sons.Mutational analysis was performed by the next-generation sequencing technology and the mutation event was confirmed by Sanger sequencing technology.Results Two patients of the family presenting as Alzheimer's dementia were late onset.MRI of the proband showed extensive cerebral microbleeds.The gene detection showed p.S289P mutation in the exon 8 of presenilin 1 of the proband.Conclusion Mutation of p.S289P in the presenilin 1 gene may contribute to late onset Alzheimer's disease accompanied by amyloid angiopathy.

iPSC Modeling of Presenilin1 Mutation in Alzheimer's Disease with Cerebellar Ataxia

Disease modeling of Alzheimer's disease (AD) has been hampered by the lack of suitable cellular models while animal models are mainly based on the overexpression of AD-related genes which often results in an overemphasis of certain pathways and is also confounded by aging. In this study, we therefore developed and used induced pluripotent stem cell (iPSC) lines from a middle-aged AD patient with a known presenilin 1 (PSEN1) mutation (Glu120Lys; PS1-E120K) and as a control, an elderly normal subject. Using this approach, we demonstrated that the extracellular accumulation of Aβ was dramatically increased in PS1-E120K iPSC-derived neurons compared with the control iPSC line. PS1-E120K iPSC-derived neurons also exhibited high levels of phosphorylated tau, as well as mitochondrial abnormalities and defective autophagy. Given that the effect of aging is lost with iPSC generation, these abnormal cellular features are therefore indicative of PSEN1-associated AD pathogenesis rather than primary changes associated with aging. Taken together, this iPSC-based approach of AD modeling can now be used to better understand AD pathogenesis as well as a tool for drug discovery.

Kidney-reinforcing and Governor Vessel-regulating EA Intervention May Improve Learningmemory Possibly by Suppressing Formation of Senile Plaques in Hippocampus in APP/PS 1 Double Transgenic Alzheimer's Disease Mice / 针刺研究

OBJECTIVE: To observe the effect of electroacupuncture (EA) intervention on learning-memory ability and the expression of senile plaques (SP), amyloid precursor protein (APP), β-secretase 1(BACE 1) and insulin degrading enzyme (IDE) in the hippocampus in APP/presenilin 1 (PS 1) double transgenic Alzheimer's disease (AD) mice, so as to reveal its mechanisms underlying improvement of AD. METHODS: A total of 18 male APP/PS 1 double transgenic AD mice were randomly divided into model, EA-2-week and EA-3-week groups (n=6 in each). The control group was consisted of 6 male wild mice. EA (2 Hz, 2 mA) was applied to "Baihui" (GV 20) and bilateral "Shenshu" (BL 23) for 15 min, once a day, with 7 days being a therapeutic course, 2 or 3 courses altogether and with an one day's interval between every two courses. The spatial learning-memory ability was assessed using Morris water maze test during 5 days' training. The immunoactivity of SP in the hippocampus tissue was detected by immunohistochemistry, and the expression levels of APP, BACE 1 and IDE in the hippocampus were analyzed by Western blot. RESULTS: Following modeling, the escape latency and path length of hidden platform tests were significantly increased (P<0.01, P<0.05), and the platform crossing time of spatial probing test significantly decreased (P<0.01) in the model group compared with the control group. After EA intervention, the escape latency on the 5th day of training, and the path length on the 4th and 5th day of training in both EA-2-week and EA-3-week groups were significantly shorter relevant to the model group (P<0.01), and those of the EA-3-week group were considerably shorter than those of the EA-2-week group in the escape latency and path length (P<0.05, P<0.01). The platform crossing times of spatial probing test were significanthy increased in both EA-2-week and EA-3-week groups in comparison with the model group (P<0.01), and that of the EA-3-week group was considerably increased compared with the EA-2-week group (P<0.05). Immunohistochemical staining showed that the number of SP in the hippocampus was markedly increased in the model group compared with the control group (P<0.01), and was markedly reduced in both EA-2-week and EA-3-week groups (P<0.01), and that of the EA-3-week group was significantly decreased compared with the EA-2-week group (P<0.01). The expression levels of hippocampal APP and BACE 1 proteins were significantly higher in the model group than in the control group (P<0.01), and that of hippocampal IDE was markedly lower in the model group than in the control group (P<0.01). After EA, the increased expression levels of APP and BACE 1 proteins and the decreased expression level of IDE in the EA-2-week and EA-3-week groups were significantly inhibited (P<0.01). The effects of EA-3-week were significantly stronger than those of EA-2-week in down-regulating the expression of APP and BACE 1 proteins and up-regulating the expression of IDE (P<0.01, P<0.05). CONCLUSION: EA stimulation of GV 20 and BL 23 can improve the learning-memory ability in APP/PS 1 double transgenic AD mice, which may be related to its effects in down-regulating the expression of SP, APP and BACE 1 proteins and up-regulating the expression of IDE protein in the hippocampus.

Presenilin 1 gene mutation p.L226R in a Chinese early-onset familial Alzheimer's disease pedigree / 中华神经科杂志

Objective To analyze the clinical presentation , the mutation of the pathogenic genes and imaging features in a Chinese Han early-onset Alzheimer's disease pedigree.Methods A pedigree of Alzheimer's disease was collected.The DNA sequence of presenilin 1 (PSEN1), presenilin 2, micro-tubule associated protein tau ,β-amyloid precursor protein gene was analyzed , the clinical presentation , results of accessory examination , neuropsychological evaluation of the proband were investigated and the point mutations of some members of the family , 50 sporadic Alzheimer's disease patients , 50 normal controls were verified.Results The proband of the family appeared as language impairment , memory loss, personality change, repeated language, visuospatial impairment, mental and behavior disorder.The gene detection showed p.L226R mutation in the condon 226 in the exon 7 of PSEN1 gene of the proband and five other family members (Ⅲ1 ,Ⅲ2 ,Ⅲ4 ,Ⅲ6 ,Ⅲ7 ).The mother of the proband had the suspicious symptoms , and the sister and the brother of the proband had the similiar symptoms with the proband , all of whom died.Fifty sporadic Alzheimer'disease patients and 50 unrelated normal subjects did not have the mutation .The computed tomographic angiography showed that the brain blood vessels were normal and 18 F-fludeoxyglucose positron emission tomography (18F-FDG-PET) showed brain atrophy and hypometabolism in frontotemporal regions, parietal regions, hippocampal areas, however, the MRI, MRA and 18F-FDG-PET of the two mutation carriers (Ⅲ6 ,Ⅲ7 ) were all normal.Conclusion We reported a novel mutation in an early-onset Alzheimer's disease family presented as language impairment in the early stage of the disease , the p.L226R mutation of PSEN1, which may be a pathogenic mutation to cause the family's dementia.

Descripción genotípica y fenotípica de la enfermedad de Alzheimer tardía y familiar precoz: revisión / Genotypic and phenotypic description of late-onset Alzheimer's disease and early onset familial Alzheimer's: Review / Descrição genotípica e fenotípica da doença de Alzheimer tardia e familiar precoce: revisão

La demencia es la pérdida de varias áreas del funcionamiento cognitivo respecto al nivel premórbido, con deterioro significativo en la funcionalidad. La más común es ocasionada por la enfermedad de Alzheimer, que se define como un trastorno neurodegenerativo que produce una alteración progresiva de la memoria y de otras habilidades mentales, por una pérdida de volumen en los lóbulos temporales, en especial en las áreas mediales como el hipocampo y la corteza entorrinal. Menos del 5% de los pacientes con esta enfermedad presenta formas hereditarias que pueden tener un inicio precoz (antes de los 65 años) o tardío (después de dicha edad). La EA precoz presenta un patrón de herencia autosómico dominante y puede ser causado por mutaciones en el gen de la proteína precursora de amiloide, en presenilina-1 o presenilina-2. Los casos de EA tardía, están influenciados por una genética compleja, con múltiples factores de susceptibilidad y el alelo ApoE4 es el principal y más reconocido. La EA es una enfermedad heterogénea tanto en su genotipo como en su fenotipo que varían en cuanto a intensidad y tipo de síntomas, edad de inicio y severidad de la demencia, de acuerdo con las mutaciones que el paciente presenta y su interacción con factores ambientales.

Dementia is known as the loss of multiple areas of cognitive function with respect to a premorbid condition, involving a significant deterioration in functionality. The most common subtype is Alzheimer's disease, which is defined as a neurodegenerative disorder that causes a progressive deterioration in memory and other mental capacities due to volume loss in temporal lobes, especially in mesial aspects, such as the hippocampus and the entorhinal cortex. Approximately 5% of patients affected by this disease have a hereditary form, with an early onset (before 65 years) or a late onset (after 65 years). Early onset Alzheimer's disease has a genetic autosomal dominant inheritance pattern, which can be caused by mutations in the gene encoding for the amyloid precursor protein, presenilin-1, or presenilin-2. In the cases of late onset Alzheimer's disease, there is a complex genetic influence, with multiple susceptibility factors, where the ApoE4 allele is the main and most recognized factor. Alzheimer's disease is a heterogeneous dementia, both in genotype and phenotype, varying in intensity and symptoms, age of onset, and severity of the disease, depending on the different mutations that a patient may have and the interactions with environmental factors.

A demência é a perda de várias áreas do funcionamento cognitivo com respeito ao nível pré-mórbido, com deterioro significativo na funcionalidade. A mais comum é ocasionada pela doença de Alzheimer, que se define como um transtorno neurodegenerativo que produz uma alteração progressiva da memória e de outras habilidades mentais, por uma perda de volume nos lóbulos temporais, em especial nas áreas mediais como o hipocampo e o córtex entorrinal. Menos de 5% dos pacientes com esta doença apresenta formas hereditárias que podem ter um início precoce (antes dos 65 anos) ou tardio (depois de dita idade). A D.A. precoce apresenta um padrão de herança autossômico dominante e pode ser causado por mutações no gene da proteína precursora de amiloide, em presenilina-1 ou presenilina-2. Os casos de D.A. tardia, estão influenciados por uma genética complexa, com múltiplos fatores de susceptibilidade e o alelo ApoE4 é o principal e mais reconhecido. A D.A. é uma doença heterogénea tanto em seu genótipo como em seu fenótipo que variam em quanto a intensidade e tipo de sintomas, idade de inicio e severidade da demência, de acordo com as mutações que o paciente apresenta e sua interação com fatores ambientais.

Association between Presenilin 1 gene methylation and sporadic Alzheimer's disease / 中华老年医学杂志

Objective To investigate the correlation between Presenilin 1 gene methylation (PSEN1) and sporadic Alzheimer's disease (SAD).Methods Massarray method was used to perform an analysis of DNA methylation in the promoters of PSEN1 gene in lymphocytes from 35 SAD patients,33 mild cognitive impaired (MCI)patients and 22 age-and gender-matched controls.Reporter gene plasmid of PSEN1 was built by genetic recombination methods,and then transiently transfected into the SH-SY5Y and HeLa cells.After that,cells were treated with several agents including serum deprivation,Aβ25-35,5-aza-2'-deoxycytidine (5-aza Cdr) and S-adenosyl-Lmethionine (SAM).A dual-luciferase reporter assay system was used to calculate the relative luciferase activity (RLA).Results Some CpG sites of PSEN1 (Cytosines at-173,95 and +76) showed hypomethylation patterns in SAD cases as compared with MCI and control group (P＜0.01).A dual-luciferase reporter assay showing significant differences in PSEN1 transcription activities were found in both cell lines under SAM treatment [SY5Y,SAM:(6.40±0.81),control:(9.13±1.67),P=0.000; Hela,SAM:(2.06±0.34),control:(2.99±0.59),P=0.000].Conclusions DNA hypomethylation of PSEN1 gene promoter is significantly associated with SAD susceptibility.PSEN1 may change the gene transcription level by methylation,further affecting the activity of amyloid protein-like γ-secretase,leading to the onset of AD.

Effects of Shouwu-Yizhi capsule on learning and memory and the expressions of presenilin 1,β-amyloid precursor protein mRNAs in the hippocampus following cerebral ischemia reperfusion in rats / 国际中医中药杂志

Objective To investigate the effects of Shouwu-Yizhi capsule on learning and memory, and the expressions of presenilin 1(PS1),β-amyloid precursor protein (APP) mRNAs in the hippocampus following cerebral ischemia reperfusion in rats. Methods Sprague–Dawley rats were randomly divided into a Shouwu-Yizhi group, a piracetam group, a model group, and a sham operation group with 20 rats in each group. Focal cerebral ischemia reperfusion model was induced by middle cerebral artery occlusion for 2 hours. Seven days after ischemia reperfusion, the rats in the Shouwu-Yizhi and piracetam groups were administered intragastrically Shouwu-Yizhi solution (52 mg/ml) and piracetam solution (28 mg/ml) for 28 days, both in dose of 1 ml/(100 g?d) for 28 days;and the rats in the model and sham operation groups were given intragastrically equivalent volumes of normal saline. Learning and memory were tested using the Morris water maze, and the expressions of PS1 and APP mRNAs were measured using real-time quantitative fluorescent PCR. Results Water maze test showed that the escape latency (12.98±0.70s vs. 9.43±0.78s) was significantly shorter, and the frequency of crossing platform (5.08±0.39 vs. 7.62±0.43) significantly lower in the model groupthan those in the sham operation group; the escape latency (9.77±0.58s vs. 12.98±0.70s) was significantly shorter and the frequency of crossing platform (7.40±0.44 vs. 5.08±0.39) significantly lower in the Shouwu-Yizhi group than those in the model group(all P<0.01). The expressions of PS1 (0.99±0.01 vs. 1.08± 0.03)and APP (1.06±0.03 vs. 1.12±0.04) mRNAs in the hippocampus in the Shouwu-Yizhi group were significantly decreased than those in the model group (P<0.05 or 0.01). Conclusion Shouwu-Yizhi capsule may inhibit the expressions of PS1 and APP mRNAs in the hippocampus, and improve the learning and memory following cerebral ischemia reperfusion in rats.

Protective effects of Acanthopanax divaricatus extract in mouse models of Alzheimer's disease

BACKGROUND: Acanthopanax divaricatus var. albeofructus (ADA) extract has been reported to have anti-oxidant, immunomodulatory, and anti-mutagenic activity. MATERIALS/METHODS: We investigated the effects of ADA extract on two mouse models of Alzheimer's disease (AD); intracerebroventricular injection of beta-amyloid peptide (Abeta) and amyloid precursor protein/presenilin 1 (APP/PS1)-transgenic mice. RESULTS: Intra-gastric administration of ADA stem extract (0.25 g/kg, every 12 hrs started from one day prior to injection of Abeta1-42 until evaluation) effectively blocked Abeta1-42-induced impairment in passive avoidance performance, and Abeta1-42-induced increase in immunoreactivities of glial fibrillary acidic protein and interleukin (IL)-1alpha in the hippocampus. In addition, it alleviated the Abeta1-42-induced decrease in acetylcholine and increase in malondialdehyde levels in the cortex. In APP/PS1-transgenic mice, chronic oral administration of ADA stem extract (0.1 or 0.5 g/kg/day for six months from the age of six to 12 months) resulted in significantly enhanced performance of the novel-object recognition task, and reduced amyloid deposition and IL-1beta in the brain. CONCLUSIONS: The results of this study suggest that ADA stem extract may be useful for prevention and treatment of AD.

Protective effects of Acanthopanax divaricatus extract in mouse models of Alzheimer's disease

BACKGROUND: Acanthopanax divaricatus var. albeofructus (ADA) extract has been reported to have anti-oxidant, immunomodulatory, and anti-mutagenic activity. MATERIALS/METHODS: We investigated the effects of ADA extract on two mouse models of Alzheimer's disease (AD); intracerebroventricular injection of beta-amyloid peptide (Abeta) and amyloid precursor protein/presenilin 1 (APP/PS1)-transgenic mice. RESULTS: Intra-gastric administration of ADA stem extract (0.25 g/kg, every 12 hrs started from one day prior to injection of Abeta1-42 until evaluation) effectively blocked Abeta1-42-induced impairment in passive avoidance performance, and Abeta1-42-induced increase in immunoreactivities of glial fibrillary acidic protein and interleukin (IL)-1alpha in the hippocampus. In addition, it alleviated the Abeta1-42-induced decrease in acetylcholine and increase in malondialdehyde levels in the cortex. In APP/PS1-transgenic mice, chronic oral administration of ADA stem extract (0.1 or 0.5 g/kg/day for six months from the age of six to 12 months) resulted in significantly enhanced performance of the novel-object recognition task, and reduced amyloid deposition and IL-1beta in the brain. CONCLUSIONS: The results of this study suggest that ADA stem extract may be useful for prevention and treatment of AD.

Effect of catalpol on senile plaques and spatial learning and memory ability in amyloid-β protein precursor/presenilin 1 double transgenic mice / 中华神经科杂志

Objective To investigate whether catalpol affects senile plaque formation and spatial learning and memory ability in the amyloid-β protein precursor/presenilin 1 (APP/PSI) double transgenic mice.Methods Three month-old APP/PS1 double transgenic mice were randomly divided into catalpoltreated and saline-treated groups (n =10),with C57 mice of the same age and genetic background as normal control group (n =10).The catalpol (in a dose of 5 mg · kg-1 · d-1) and the same amount of saline were peritoneally injected into Alzheimer' s disease (AD) model mice for 3 weeks.Immunohistochemical staining was performed to examine senile plaques in the brain of AD model mice,and Morris water maze was used to assess the spatial learning and memory abilities of the mice.Results Compared with the saline-treated AD model mice (6.0 ±0.6),the number of senile plaques of catalpol treated AD mice significantly decreased (2.3± 0.7; t =3.500,P =0.025); Mice in each groups had similar latency and path length to reach platform in visible platform test; In hidden platform test,catalpol-treated mice had a significant lesser latency and path length compared with saline-treated mice,furthermore,catalpol-treated mice had much more platform-crossing times (6.4 ± 0.8) than saline-treated mice (2.9 ± 0.4 ; t =5.592,P =0.001).Conclusion Catalpol can significantly decrease the senile plaque formation and improve the spatial learning and memory abilities of APP/PS1 double transgenic mice.

Mutation analysis of presenilin-1 gene in Alzheimer' s disease patients and the effects of its mutation on expression of presenilin-1 and amyloid precursor protein / 中华神经科杂志

Objective To analyze the resenilin-1 (PS-1) gene mutations in Alzheimer' s disease (AD) patients and investigate the influence of the initiation codon mutation on the mRNA expression of PS-1 and amyloid precursor protein (APP) genes and the expression of PS-1 proteins.Methods (1) All 111 AD patients were enrolled by the Department of Neurology,Second Affiliated Hospital,College of Medicine,Zhejiang University from July 2004 to June 2010.Mutations in the 13 exons and flanking regions of PS-1 gene were examined by direct sequencing.(2) cDNAs encoding full-length wild-type and mutant (c.1A ＞G) PS-1 were subcloned into enhanced green fluorescent protein.Levels of the mRNA expression of PS-1 and APP genes and PS-1 proteins expression in the transfected cells were detected by quantitative real-time PCR and Western blot,respectively.Results A new heterozygous initiation codon mutation changing from ATG to GTG in one individual was identified.Compared to the control groups,the mRNA expression of the mutant PS-1 gene in HEK293 and N2a was significantly lower than the normal PS-1 gene(116.8 ± 3.9 vs 49.5 ±3.3,t =13.27,P ＜0.01 ;69.0 ± 1.9 vs 29.5 ± 1.3,t =17.20,P ＜0.01) and the APP gene was not obviously altered.The proteins were detected by Western blot analysis in HEK293 cells but not in N2a cells.Conclusions Since we only identified one novel heterozygous initiation codon mutation (from ATG to GTG),mutations in PS-1 are likely to be rare in AD patients.Initiation codon mutation would reduce the expression of PS-1 proteins.Inactivation of some of the PS-1 proteins could be insufficient to lead to AD and could be more likelv to act as a risk factor.

The study on the role of transcription factor GATA binding protein 3 in familial Alzheimer's disease pathogenesis / 中华神经科杂志

Objective To investigate the mechanisms of decreasing insulin degrading enzyme (IDE) level by mutation V97L in the gene presenilin 1 (PS-1).Methods Transcription factor GATA binding protein 3 (GATA-3) activity was assessed by protein/DNA array and verified by Western blot in SH-SY5Y cells transfected by PS-1 mutation V97L.Results Protein/DNA array and Western blot revealed that there was increased transcript factor activity (5.5 times high) and protein level of GATA-3 in V97L-PS-1 transfected SH-SY5Y cells.Transcription factor GATA-3 can bind to the IDE promoter and negatively control the IDE transcription level.Conclusion PS-1 mutation V97L may regulate the transcription of IDE via GATA-3, and subsequently involve in deposition of Aβ42 and development of Alzheimer's disease.

Effects of presenilin-1 V97L mutation on neprilysin expressing in SH-SYSY cell / 中华神经科杂志

Objective To study the mechanisms of increasing amyloid [β1-42 (Aβ42) level by presenilin-1 (PS-1) mutation of V97L.Methods Expression level of neprilysin (NEP) in nontransfected, or mock vector, wild type (wt) PS-1 and V97L-PS-1-transfected SH-SY5Y cells were assessed by reverse transcriptional-polymerase chain reaction (RT-PCR) and Western blot.The level of Aβ42 was also assessed by enzyme linked immunosorbent assay (ELISA).Results The mRNA level of NEP was decreased significantly in PS-1 V97L transfected cells (0.650 ± 0.010) compared to that in normal cells (1.090 ± 0.015), wt PS-1 gene (1.040 ± 0.021) and mock (1.080 ± 0.020) stably transfected cell lines (t = 9.236, 10.452, 5.678; all P < 0.01).Although there was a decreased tendency in the protein expression of NEP in PS-Ⅰ V97L transfected cells (1.000 ± 0.126)compared to that in normal cells (1.020 ± 0.110), wt PS-1 gene (1.040 ±0.110), mock (2.130 ±0.130) stably transfected cell lines, nosignificant differences were found.The expression of Aβ42 was increased significantly in PS-1 V97L transfected cells compared to other cell lines (t = 2.109, 3.355, 3.976; all P < 0.01).Conclusions PS-1 V97L mutation can decrease the transcription of NEP, however, in contrast, this mutation also resulted in increased Aβ42.The mechanism needs further analysis.

Perfil clínico y cognitivo de la atrofia cortical posterior y sus diferencias con la enfermedad de Alzheimer esporádica tardía y familiar precoz / Clinical and cognitive profile of posterior cortical atrophy and its differences with late sporadic and early familial Alzheimer's disease

Introducción. La atrofia cortical posterior (ACP) es una demencia focal que se manifiesta al inicio con trastornos cognitivos posteriores, principalmente alteración visuoperceptual por el daño en la corteza occipitoparietal, lo que permite en la clínica diferenciarla de la enfermedad de Alzheimer (EA). Objetivos. Analizar y comparar el rendimiento cognitivo de pacientes con ACP y con EA. Materiales y métodos. La muestra estuvo formada por los siguientes grupos: cuatro pacientes con ACP, siete con EA familiar precoz, nueve con EA esporádica tardía y cuatro controles sanos. A cada participante se le aplicó un protocolo de evaluación neuropsicológica para valorar procesos cognitivos y funcionalidad. La comparación entre grupos se realizó utilizando la prueba no paramétrica U de Mann-Whitney. Resultados. Los pacientes con ACP obtuvieron puntuaciones significativamente inferiores en praxias constructivas e ideacionales, lectura, cálculo y visuopercepción, respecto a ambos grupos de EA. Por el contrario, en memoria verbal, fluidez semántica y función ejecutiva, el grupo con ACP presentó mejor desempeño. Conclusión. Al inicio del proceso neurodegenerativo la clínica de la ACP se diferencia de la de EA. La ACP es una demencia con características sintomatológicas propias y no sólo una variante de la EA, aunque ambas compartan el mismo sustrato histopatológico.

Introduction. Posterior cortical atrophy (PCA) is a focal dementia manifested by posterior cognitive disorders, initially visuoperceptual alterations due to damage in occipito-parietal cortex, which permits PCA to be clinicallydifferentiated of Alzheimer's Disease (AD). Objetive. To analize and to compare cognitive performance of patients with PCA and with AD. Materials and methods. Sample was conformed by the following groups: four patients with PCA, seven with early familial AD, nine with late sporadic AD and four healthy controls. A neuropsychological examination battery was administrated to each participant in order to assess cognitive processes and functionality. Between-groups comparisons were made by using U Mann-Whitney non parametric test.Results. Patients with PCA had significantly lower scores in constructional and ideational praxias, reading, calculation andvisuoperception, compared to both AD groups. In contrast, PCA group showed better performance in verbal memory,semantic fluency and executive function.Conclusion. At the beginning of neurodegenerative process, PCA symptomatology is clearly different of that presented in AD. PCA is a dementia with particular symptomatic characteristics and not only a variant of AD, even if both share the same hystopathological substrate.

Study on the interaction between presenilin 1 and carboxyl terminus of Hsc70 interacting protein / 中华老年医学杂志

ObjectiveTo understand the pathological and physiological roles of Presenilin 1 (PS1) in Alzheimer's disease (AD) recurrence, and the interaction between PSI and carhoxyl terminus of Hsc70 interacting protein (CHIP). MethodsThe yeast two-hybrid system was applied to identify a novel PS1 interacting protein as CHIP. After pGBKT7-PS1-C203 bait plasmid and full fragement CHIP of pACT2-CHIP expression vector were constructed, the interaction between PSI and CHIP was tested by β-galactosidase assay, pGBKT7-PS1-C203 was co-transfected with pACT2-CHIP into 293T cells and the interaction between PS1 and CHIP was tested by co-immunoprecipitation and Western blot. ResultsSpecificity of the interaction between PS1 and CHIP was identified by β-galactosidase assay and co- immunoprecipitation. ConclusionsCHIP is able to modulate chaperone functions and the pathway of protein ubiquitination/degradation. CHIP may regulate a proper assembly of the γ-secretase complex through its interaction with PSI, which is helpful to elucidate the mechanism of AD pathology.

Identification of PSEN1 and APP Gene Mutations in Korean Patients with Early-Onset Alzheimer's Disease

Although mutations in three genes, amyloid precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2), have been identified as genetic causes of earlyonset Alzheimer s disease (EOAD), there has been a single report on a PSEN1 mutation in Koreans. In the present study, we performed a genetic analysis of six Korean patients with EOAD. Direct sequencing analysis of the APP, PSEN1 and PSEN2 genes revealed two different mutations of the PSEN1 gene (G206S and M233T) and one mutation of the APP gene (V715M) in three patients with age-atonset of 34, 35, and 42 yr, respectively. In addition, two patients with age-at-onset of 55 and 62 yr, respectively, were homozygous for APOE epsilon 4 allele. One woman had no genetic alterations. These findings suggest that PSEN1 and APP gene mutations may not be uncommon in Korean patients with EOAD and that genetic analysis should be provided to EOAD patients not only for the identification of their genetic causes but also for the appropriate genetic counseling.

Influence of presenilin 1 overexpression on endogenous tau phosphorylation in neuroblastoma cells / 复旦学报（医学版）

Purpose To study the effect of overexpressing either wild type or a familial Alzheimer disease mutant presenilin 1 (mPS1) on tau phosphorylation in neuroblastoma NG-108 cells. Methods Three different plasmids transfected NG-108 cells respectively. Immunostaining and confocal microscopic technique were used to study the distribution of presenilin 1 and phosphorylated tau. Immunoblot test was applied to investigate the change of tau phosphorylation. Results Immunostaining showed that in brain of sporadic Alzheimer disease, PS1 mainly distributed in neuron and partially colocalized with the phosphorylated tau. Immunoblot tests showed that the cells transected either wild type PS1 or mPS1 contained more phorphorylated tau than the control cells. However, MTT test showed no significant difference between mock transfected cells and the wPS1 or mPS1 transfected cells. In addition, after transfection of the constructed PS1-EGFP vector, overexpressed EGFP-PS1 was located at cell surface membrane and subcellular organelles at earlier time at 12 hr, then EGFP-PS1 diffused in cytosol. Immunocytochemical observations demonstrated that some of the PS1-EGFP transfected cells contained more phosphorylated tau protein, which formed aggresome with PS-1-EGFP. When treated with phosphotase inhibitor okadaic acid, in the PS1-EGFP transfected cells accumulated more phosphorylated tau than the un-transfected cells. Conclusions Wild type PS1 is possibly involved in tauopathy in sporadic Alzheimer's disease.