OBJECTIVE: To explore whether the protein Deglycase protein 1 (DJ1) can ameliorate Alzheimer's disease (AD)-like pathology in Amyloid Precursor Protein/Presenilin 1 (APP/PS1) double transgenic mice and its possible mechanism to provide a theoretical basis for exploring the pathogenesis of AD. METHODS: Adeno-associated viral vectors (AAV) of DJ1-overexpression or DJ1-knockdown were injected into the hippocampus of 7-month-old APP/PS1 mice to construct models of overexpression or knockdown. Mice were divided into the AD model control group (MC), AAV vector control group (NC), DJ1-overexpression group (DJ1 ⁺), and DJ1-knockdown group (DJ1 ^-). After 21 days, the Morris water maze test, immunohistochemistry, immunofluorescence, and western blotting were used to evaluate the effects of DJ1 on mice. RESULTS: DJ1 ⁺ overexpression decreased the latency and increased the number of platform traversals in the water maze test. DJ1 ^- cells were cured and atrophied, and the intercellular structure was relaxed; the number of age spots and the expression of AD-related proteins were significantly increased. DJ1 ⁺ increased the protein expression of Nuclear factor erythroid 2-related factor 2 (NRF2), heme oxygenase-1 (HO-1), light chain 3 (LC3), phosphorylated AMPK (p-AMPK), and B cell lymphoma-2 (BCL-2), as well as the antioxidant levels of total superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC), and Glutathione peroxidase (GSH-PX), while decreasing the levels of Kelch-like hydrates-associated protein 1 (Keap1), mammalian target of rapamycin (mTOR), p62/sequestosome1 (p62/SQSTM1), Caspase3, and malondialdehyde (MDA). CONCLUSION DJ1-overexpression can ameliorate learning, memory, and AD-like pathology in APP/PS1 mice, which may be related to the activation of the NRF2/HO-1 and AMPK/mTOR pathways by DJ1.
Animals ; Mice ; Alzheimer Disease/therapy* ; AMP-Activated Protein Kinases/metabolism* ; Amyloid beta-Protein Precursor/metabolism* ; Antioxidants/metabolism* ; Disease Models, Animal ; Hippocampus/metabolism* ; Kelch-Like ECH-Associated Protein 1/metabolism* ; Mammals/metabolism* ; Mice, Inbred C57BL ; Mice, Transgenic ; NF-E2-Related Factor 2/metabolism* ; Presenilin-1/metabolism* ; TOR Serine-Threonine Kinases/metabolism*

Sleep exerts important functions in the regulation of cognition and emotion. Recent studies have found that sleep disorder is one of the important risk factors for Alzheimer's disease (AD), but the effects of chronic sleep deprivation on the cognitive functions of AD model mice and its possible mechanism are still unclear. In the present study, 8-month-old male APP/PS1/tau triple transgenic AD model (3xTg-AD) mice and wild type (WT) mice (n = 8 for each group) were subjected to chronic sleep deprivation by using the modified multiple platform method, with 20 h of sleep deprivation each day for 21 days. Then, open field test, elevated plus maze test, sugar water preference test, object recognition test, Y maze test and conditioned fear memory test were performed to evaluate anxiety- and depression-like behaviors, and multiple cognitive functions. In addition, the immunohistochemistry technique was used to observe pathological characteristics in the hippocampus of mice. The results showed that: (1) Chronic sleep deprivation did not affect anxiety- (P = 0.539) and depression-like behaviors (P = 0.874) in 3xTg-AD mice; (2) Chronic sleep deprivation exacerbated the impairments of object recognition memory (P < 0.001), working memory (P = 0.002) and the conditioned fear memory (P = 0.039) in 3xTg-AD mice; (3) Chronic sleep deprivation increased amyloid β (Aβ) deposition (P < 0.001) and microglial activation (P < 0.001) in the hippocampus of 3xTg-AD mice, without inducing abnormal tau phosphorylation and neurofibrillary tangles. These results indicate that chronic sleep deprivation exacerbates the impairments of recognition memory, working memory and conditioned fear memory in 3xTg-AD mice by aggravating Aβ deposition and the excessive activation of microglia in the hippocampus.
Alzheimer Disease ; Amyloid beta-Peptides ; Amyloid beta-Protein Precursor/genetics* ; Animals ; Cognition ; Disease Models, Animal ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Presenilin-1 ; Sleep Deprivation ; tau Proteins

Alzheimer's disease (AD) is the most common senile neurodegenerative disease characterized by progressive cognitive dysfunction, psychological and behavioral abnormalities, and impaired ability of activities of daily living. A family with a total of 3 patients were admitted to the Department of Neurology of Xiangya Hospital, Central South University in 2018. The proband showed memory decline as the presenting symptoms, and subsequently showed psychological and behavioral abnormalities, personality changes, seizures, and motor retardation. Definite diagnosis of early-onset familial AD (EOFAD) with missense mutation of presenilin 2 (PSEN2) (c.715A>G p.M239V) was established by whole exome sequencing (WES) technology. We reported the mutation in Chinese Han population for the first time, which expanded the mutation spectrum ofPSEN2 gene and aid to enrich the characterization of clinical phenotype in EOFAD associated to PSEN2 mutations. Patients with early onset age and complex clinical manifestations of AD can be diagnosed with the help of genetic testing to avoid misdiagnosis.
Activities of Daily Living ; Alzheimer Disease/genetics* ; Humans ; Mutation ; Neurodegenerative Diseases ; Presenilin-1/genetics* ; Presenilin-2/genetics*

The link of diabetes with co-occurring disorders in the brain involves complex and multifactorial pathways. Genetically engineered rodents that express familial Alzheimer's disease-associated mutant forms of amyloid precursor protein and presenilin 1 (PSEN1) genes provided invaluable insights into the mechanisms and consequences of amyloid deposition in the brain. Adding diabetes factors (obesity, insulin impairment) to these animal models to predict success in translation to clinic have proven useful at some extent only. Here, we focus on contributing factors to diabetic brain injury with the aim of identifying appropriate animal models that can be used to mechanistically dissect the pathophysiology of diabetes-associated cognitive dysfunction and how diabetes medications may influence the development and progression of cognitive decline in humans with diabetes.
Amyloid ; Brain Injuries ; Brain ; Dementia ; Diabetes Mellitus ; Humans ; Insulin ; Models, Animal ; Obesity ; Plaque, Amyloid ; Presenilin-1 ; Rodentia

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.
Aged ; Aging ; Alzheimer Disease* ; Autophagy ; Cerebellar Ataxia* ; Drug Discovery ; Humans ; Models, Animal ; Neurons ; Pluripotent Stem Cells ; Presenilin-1 ; Stem Cells

PURPOSE: Presenilins are functionally important components of γ-secretase, which cleaves a number of transmembrane proteins. Manipulations of PSEN1 and PSEN2 have been separately studied in Alzheimer disease (AD) and cancer because both involve substrates of γ-secretase. However, numerous clinical studies have reported an inverse correlation between AD and cancer. Interestingly, AD is a neurodegenerative disorder, whereas cancer is characterized by the proliferation of malignant cells. However, this inverse correlation in the PSEN double-knockout (PSEN dKO) mouse model of AD has been not elucidated, although doing so would shed light onto the relationship between AD and cancer. METHODS: To investigate the inverse relationship of AD and cancer under conditions of PSEN loss, we used the hippocampus of 7-month-old and 18-month-old PSEN dKO mice for a microRNA (miRNA) microarray analysis, and explored the tumorsuppressive or oncogenic role of differentially-expressed miRNAs. RESULTS: The total number of miRNAs that showed changes in expression level was greater at 18 months of age than at 7 months. Most of the putative target genes of the differentially-expressed miRNAs involved Cancer pathways. CONCLUSIONS: Based on literature reviews, many of the miRNAs involved in Cancer pathways were found to be known tumorsuppressive miRNAs, and their target genes were known or putative oncogenes. In conclusion, the expression levels of known tumor-suppressive miRNAs increased at 7 and 18 months, in the PSEN dKO mouse model of AD, supporting the negative correlation between AD and cancer.
Alzheimer Disease* ; Animals ; Hippocampus ; Humans ; Infant ; Mice* ; Microarray Analysis ; MicroRNAs ; Neurodegenerative Diseases ; Oncogenes ; Presenilins

OBJECTIVES: To identify the genotype of (APP/PS1) transgenic mice and evaluate the changing of cognitive and behavioral fu nctions, provide an effective animal model for the Alzheimer's disease (AD) research. METHODS: Male APP/PS1 transgenic mice mated with female APP/PS1 transgenic mice, and the genotype of their filial mice was identified by PCR. The APP +/PS1 + mice were assigned into AD model group (AD group, =8), and the APP/PS1 mice were assigned into control group (CT group, =8). The Morris water maze test was carried out to detect the capacity of learning and memory of mice. After that, the mice were sacrificed and the brain tissues were sampled and stained by HE and congo red for the pathological examination. RESULTS: ①A APP/PS1 genome DNA about 360 bp size was detected. The methods of feeding and breeding were successful to attain APP/PS1 transgenic mice.②Statistical significance was found in the differences of the capacity of learning and memory between 7-month-old APP/PS1 positive mice and negative mice (<0.05).③The results of HE stain showed that the structure and cellular morphology of hippocampus of AD mice were obviously abnormal. The results of congo red stain showed that positive amyloid plaque was observed in brains of AD mice. CONCLUSIONS APP/PS1 transgenic mice present typical symptoms and behaviors of Alzheimer's disease. The transgenic mouse is an effective tool for the research and prevention of AD.
Alzheimer Disease ; physiopathology ; Amyloid beta-Protein Precursor ; genetics ; Animals ; Disease Models, Animal ; Female ; Genotype ; Hippocampus ; pathology ; Male ; Maze Learning ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Plaque, Amyloid ; pathology ; Presenilin-1 ; genetics

Alzheimer's disease (AD) is the most common form of dementia among the elderly, characterized by amyloid plaques, neurofibrillary tangles, and neuroinflammation in the brain, as well as impaired cognitive behaviors. A sex difference in the prevalence of AD has been noted, while sex differences in the cerebral pathology and relevant molecular mechanisms are not well clarified. In the present study, we systematically investigated the sex differences in pathological characteristics and cognitive behavior in 12-month-old male and female APP/PS1/tau triple-transgenic AD mice (3×Tg-AD mice) and examined the molecular mechanisms. We found that female 3×Tg-AD mice displayed more prominent amyloid plaques, neurofibrillary tangles, neuroinflammation, and spatial cognitive deficits than male 3×Tg-AD mice. Furthermore, the expression levels of hippocampal protein kinase A-cAMP response element-binding protein (PKA-CREB) and p38-mitogen-activated protein kinases (MAPK) also showed sex difference in the AD mice, with a significant increase in the levels of p-PKA/p-CREB and a decrease in the p-p38 in female, but not male, 3×Tg-AD mice. We suggest that an estrogen deficiency-induced PKA-CREB-MAPK signaling disorder in 12-month-old female 3×Tg-AD mice might be involved in the serious pathological and cognitive damage in these mice. Therefore, sex differences should be taken into account in investigating AD biomarkers and related target molecules, and estrogen supplementation or PKA-CREB-MAPK stabilization could be beneficial in relieving the pathological damage in AD and improving the cognitive behavior of reproductively-senescent females.
Alzheimer Disease ; metabolism ; pathology ; psychology ; Amyloid beta-Protein Precursor ; genetics ; metabolism ; Animals ; Cyclic AMP Response Element-Binding Protein ; metabolism ; Cyclic AMP-Dependent Protein Kinases ; metabolism ; Disease Models, Animal ; Female ; Hippocampus ; metabolism ; pathology ; Humans ; Inflammation ; metabolism ; pathology ; psychology ; Male ; Maze Learning ; physiology ; Mice, Inbred C57BL ; Mice, Transgenic ; Neurofibrillary Tangles ; metabolism ; pathology ; Plaque, Amyloid ; metabolism ; pathology ; psychology ; Presenilin-1 ; genetics ; metabolism ; Sex Characteristics ; Spatial Memory ; physiology ; p38 Mitogen-Activated Protein Kinases ; metabolism ; tau Proteins ; genetics ; metabolism

Mutations in presenilin 1 (PSEN1) are the most common cause of autosomal dominant Alzheimer's disease. Here, we report a Canadian-Vietnamese family carrying a PSEN1 p.Met233Val mutation with an exceptionally early and severe presentation that includes a wide range of atypical symptoms, including prominent ataxia, Parkinsonism, spasticity, dystonia, action tremor, myoclonus, bulbar symptoms, seizures, hallucinations and behavioral changes. Whole-exome sequencing (WES) was performed on the affected proband after many assessments over several years proved diagnostically inconclusive. The results were analyzed using the AnnEx “Annotated Exomes” browser (http://annex.can.ubc.ca), a web-based platform that facilitates WES variant annotation and interpretation. High-throughput sequencing can be especially informative for complex neurological disorders, and WES warrants consideration as a first-line clinical test. Data analyses facilitated by web-based bioinformatics tools have great potential for novel insight, although confirmatory, diagnostically accredited Sanger sequencing is recommended prior to reporting.
Alzheimer Disease ; Ataxia ; Computational Biology ; Dystonia ; Exome ; Hallucinations ; Humans ; Muscle Spasticity ; Myoclonus ; Nervous System Diseases ; Parkinsonian Disorders ; Presenilin-1 ; Seizures ; Statistics as Topic ; Tremor

The purpose of this study is to investigate whether nicotinic acid (NA) and nicotinamide (NAM) reduce the Alzheimer disease (AD)-related gene expression in brain tissues of amyloid beta (Aβ)-injected mice. Male Crj:CD1 (ICR) mice were divided into 6 treatment groups; 1) control, 2) Aβ control, 3) Aβ + NA 20 mg/kg/day (NA20), 4) Aβ + NA40, 5) Aβ + NAM 200 mg/kg/day (NAM200), and 6) Aβ + NAM400. After 1-week acclimation period, the mice orally received NA or NAM once a day for a total of 7 successive days. On day 7, biotinylated Aβ42 was injected into mouse tail vein. At 5 hours after the injection, blood and tissues were collected. Aβ42 injection was confirmed by Western blot analysis of Aβ42 protein in brain tissue. NAM400 pre-treatment significantly reduced the gene expression of amyloid precursor protein and presenilin 1 in brain tissues. And, NAM200 and NAM400 pre-treatments significantly increased sirtuin 1 expression in brain tissues, which is accompanied by the decreased brain expression of nuclear factor kappa B by 2 doses of NAM. Increased expression of AD-related genes was attenuated by the NAM treatment, which suggests that NAM supplementation may be a potential preventive strategy against AD-related deleterious changes.
Acclimatization ; Aging ; Alzheimer Disease ; Amyloid* ; Animals ; Blotting, Western ; Brain* ; Gene Expression ; Humans ; Male ; Mice* ; NF-kappa B ; Niacin ; Niacinamide* ; Presenilin-1* ; Presenilins* ; Sirtuin 1 ; Tail ; Veins*