Objective: The objective of the study is to investigate whether quercetin ameliorates Alzheimer\'s disease (AD)-like pathology in APP/PS1 double transgenic mice and its hypothesized mechanism, contributing to the comprehension of AD pathogenesis. Methods: A total of 30 APP/PS1 transgenic mice were randomized into model group (APP/PS1), quercetin group (APP/PS1+Q), and donepezil hydrochloride group (APP/PS1+DON). Simultaneously, there were 10 C57 mice of the same age served as a control group. Three months posttreatment, the effects of quercetin on AD mice were evaluated using the Morris water maze (MWM) test, Y maze experiment, immunohistochemistry, immunofluorescence, and western blotting. Results: Results from the water maze and Y maze indicated that quercetin significantly improved cognitive impairment in APP/PS1 transgenic AD mice. Additionally, serum enzyme-linked immunosorbent assay (ELISA) results demonstrated that quercetin elevated MDA, superoxide dismutase (SOD), CAT, GSH, acetylcholine (ACh), and acetylcholinesterase (AChE) levels in AD mice. Hematoxylin-eosin (HE) staining, Nissl staining, and hippocampal tissue thioflavine staining revealed that quercetin reduced neuronal damage and Aβ protein accumulation in AD mice. Western blot validated protein expression in the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2)/HO-1 pathway associated with oxidative stress and apoptosis, confirming quercetin\'s potential molecular mechanism of enhancing AD mouse cognition. Furthermore, western blot findings indicate that quercetin significantly alters protein expression in the Keap1/Nrf2/HO-1 pathway. Moreover, molecular docking analysis suggests that Keap1, NQO1, HO-1, caspase-3, Bcl-2, and Bax proteins in the Keap1/Nrf2/HO-1 pathway may be potential regulatory targets of quercetin. These findings will provide a molecular basis for quercetin\'s clinical application in AD treatment. Conclusion: Quercetin can improve cognitive impairment and AD-like pathology in APP/PS1 double transgenic mice, potentially related to quercetin\'s activation of the Keap1/Nrf2/HO-1 pathway and reduction of cell apoptosis.

Objective To explore the mechanism of fasudil improving cognitive dysfunction in amyloid precursor protein/presenilin-1 (APP/PS1) transgenic mice based on mitophagy and nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome pathway. Methods APP/PS1 mice were divided into model group and treatment group, and C57BL/6 mice were used as control group. The treatment group was given intraperitoneal injection of Fasudil (25 mg/kg) once daily for 2 months, while the control group and the model group were injected with the same volume of normal saline. The behavior of mice was detected by water maze and Y maze test; Nissl staining and neuron-specific nuclear antigen (NeuN) immunofluorescence histochemical staining were used to evaluate the number and morphology of neurons. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL) staining was used to detect neuronal apoptosis; The expression of P62 and NLRP3 was detected by immunofluorescence histochemical staining; Real time fluorescence quantitative PCR was used to detect the mRNA expression levels of phosphatase and tensin homolog deleted on chromosome ten (PTEN) -induced putative kinase 1 (PINK1), Parkin and NLRP3; Western blot analysis was used to detect the expression of PINK1, Parkin, P62, microtubule-associated protein 1 light chain 3 (LC3), NLRP3, adapter protein apoptosis-associated speck-like protein (ASC) and interleukin-18 (IL-18). Results The results of the water maze and Y maze showed that the cognitive behavior of mice in treatment group was significantly improved, and their spatial memory and exploration abilities were significantly enhanced; The results of Nissl staining and NeuN immunofluorescence histochemical staining showed that the number of neurons and Nissl bodies were lower in the model group than that in the control group, while the morphology and number of neurons were improved after fasudil treatment. The results of TUNEL staining also showed that the number of apoptotic cells in the brain tissue of APP/PS1 mice were decreased after fasudil treatment; Compared with the control group, the expression of PINK1 and Parkin in the model group decreased, while the expression of P62, LC3, NLRP3, ASC and IL-18 increased. After treatment with fasudil, the expression of PINK1, Parkin, and LC3 increased, while the expression of P62, NLRP3, ASC, and IL-18 decreased. Conclusions Fasudil can improve the cognitive function and neuronal damage in APP/PS1 mice, and its mechanism may be related to promoting mitochondrial autophagy and inhibiting the activation of NLRP3 inflammasomes.

BACKGROUND: The Chinese formula Guben-Jiannao Ye (GBJNY) formula has a long history of usage in traditional Chinese medicine (TCM) for the treatment of learning and memory disorders as well as senile insomnia. This formulation is derived from Sun Simiao\'s five tonic pills. Furthermore, modern pharmacological investigations have revealed its ability to improve cognitive impairment and ameliorate sleep-wake circadian rhythm disorders. However, the precise mechanism underlying its efficacy remains elusive.
OBJECTIVE: The current research explored the modulatory effects and possible mechanisms of GBJNY in circadian rhythm sleep-wake disorders and cognitive dysfunction in Alzheimer\'s disease using transcriptome sequencing and experimental validation.
METHODS: The LC-MS/MS tandem technology was utilized to qualitatively discern the active components present in GBJNY. The APP/PS1 mice received continuous treatment with GBJNY or Melatonin for 3 months. The learning and memory abilities of mice were assessed utilizing the Morris water maze (MWM) test, while sleep changes were studied utilizing the electroencephalogram (EEG) and electromyogram (EMG). Concurrently, mice\'s hippocampus clock gene rhythmicity was investigated. Subsequently, we employed HE staining, Golgi staining, and immunofluorescence to observe GBJNY\'s impact on synaptic damage and neuronal loss. We performed high-throughput sequencing to analyze the mRNA expression profiles of mice, aiming to identify differentially expressed genes (DEGs). Subsequently, we conducted GO and KEGG enrichment analyses to explore associated signaling pathways. Furthermore, we evaluated the expression levels of proteins involved in the PI3K/AKT/mTOR pathway and Aβ deposition in the hippocampus of mice. Through this comprehensive approach, we sought to elucidate and validate the potential mechanisms of action of GBJNY in APP/PS1 mice.
RESULTS: Results showed 216 DEGs. Following this, we conducted GO enrichment and KEGG pathway analyses to delve deeper into the distinctions and fundamental functions of the mRNA target genes. The enrichment analysis underscored the prominence of the PI3K/Akt/mTOR signaling pathway as the most pivotal among them. Through in vivo experiments, it was further demonstrated that the administration of GBJNY enhanced memory and learning capacities in APP/PS1 mice. Additionally, GBJNY treatment resulted in alterations in the sleep-wake circadian rhythm, characterized by reduced wakefulness and an increase in non-rapid eye movement (NREM) sleep. Moreover, alterations in the peak expression of Per1, Per2, Clock, Cry1, Cry2, and Bmal1 mRNA were noted in the hippocampus of treated mice. Particularly noteworthy were the observed reductions in amyloid-beta (Aβ) deposition within the hippocampus, improvements in neuronal synaptic integrity, and upregulation of mTOR, Akt, and PI3K protein expression in the hippocampal region. These findings underscore the critical involvement of the PI3K/Akt/mTOR signaling pathway in mitigating disturbances in sleep-wake circadian rhythms.
CONCLUSIONS: GBJNY enhanced the cognitive performance of APP/PS1 mice and altered clock gene expression patterns, alleviating sleep-wake circadian rhythm disruptions. The fundamental mechanism appears to be linked to the PI3K/Akt/mTOR pathway regulation, offering a foundation for potential clinical applications.

Alzheimer\'s disease (AD) is closely associated with the neurotoxic effects of amyloid-β (Aβ), leading to synaptic damage, neuronal loss and cognitive dysfunction. Previous in vitro studies have demonstrated the potential of corilagin to counteract Aβ-induced oxidative stress, inflammatory injury, and β-site amyloid precursor protein cleaving enzyme-1 (BACE1) activity in Aβ production. However, the in vivo protective effects of corilagin on Alzheimer\'s disease remain unexplored. The purpose of this study was to investigate the protective effects of corilagin on APP/PS1 mice and the underlying mechanisms. The cognitive function of the mice was assessed by step-through passive avoidance and Morris water maze tests. Nissl staining was used to evaluate neuronal damage in the hippocampus. ELISA and Western blotting analyses were used to determine the associated protein expression. Transmission electron microscopy was utilized to observe the synaptic ultrastructure of hippocampal neurons. Golgi staining was applied to assess dendritic morphology and dendritic spine density in hippocampal pyramidal neurons. Immunohistochemistry and Western blotting were performed to examine the expression of synaptic-associated proteins. The results showed that corilagin improves learning and memory in APP/PS1 mice, reduces hippocampal neuron damage, inhibits BACE1 and reduces Aβ generation. It also improves synaptic plasticity and the expression of synaptic-associated proteins. Corilagin effectively reduces Aβ generation by inhibiting BACE1, ultimately reducing neuronal loss and enhancing synaptic plasticity to improve synaptic transmission. This study sheds light on the potential therapeutic role of corilagin in Alzheimer\'s disease.

With the rapid progress in deciphering the pathogenesis of Alzheimer\'s disease (AD), it has been widely accepted that the accumulation of misfolded amyloid β (Aβ) in the brain could cause the neurodegeneration in AD. Although much evidence demonstrates the neurotoxicity of Aβ, the role of Aβ in the nervous system are complex. However, more comprehensive studies are needed to understand the physiological effect of Aβ40 monomers in depth. To explore the physiological mechanism of Aβ, we employed mass spectrometry to investigate the altered proteomic events induced by a lower submicromolar concentration of Aβ. Human neuroblastoma SH-SY5Y cells were exposed to five different concentrations of Aβ1-40 monomers and collected at four time points. The proteomic analysis revealed the time-course behavior of proteins involved in biological processes, such as RNA splicing, nuclear transport and protein localization. Further biological studies indicated that Aβ40 monomers may activate PI3K/AKT signaling to regulate p-Tau, Ezrin and MAP2. These three proteins are associated with dendritic morphogenesis, neuronal polarity, synaptogenesis, axon establishment and axon elongation. Moreover, Aβ40 monomers may regulate their physiological forms by inhibiting the expression of BACE1 and APP via activation of the ERK1/2 pathway. A comprehensive exploration of pathological and physiological mechanisms of Aβ is beneficial for exploring novel treatment.

We investigate the mechanism of action of astragalin (AST) in the treatment of Alzheimer\'s disease (AD). Network pharmacology was conducted to analyze the relationships among AST, AD, and neuroinflammation, The APP/PS1 transgenic mice with AD were used in the experiments; to be specific, the influence of AST on the behavior of mice was analyzed by Morris water maze and eight-arm radial maze tests, the tissue inflammatory factor levels were detected by ELISA, and pathological changes were analyzed by H&E and immunohistochemical staining. Analysis results of network pharmacology suggested that AST exerted the multi-target effect on neuroinflammation in AD. Through molecular docking and dynamics analyses, COX2 might be the target of AST. Moreover, animal experimental results demonstrated that AST improved the behavior of AD mice, and enhanced the motor and memory abilities, meanwhile, it suppressed the expression of inflammatory factors in tissues and the activation of microglial cells. this study discovers that AST can suppress microglial cell activation via COX2 to improve neuroinflammation in AD.

Alzheimer\'s disease (AD) is a degenerative dementia illness that causes atrophy of the temporal and frontal lobes of the cerebral cortex. Linggui Zhugan (LGZG), a classic Chinese herbal formula, was initially recognized as a safe and effective treatment of cardiovascular diseases for long history. This study intended to assess the effects and the molecular mechanism of LGZG on AD progress. C57BL/6 mice were divided into six groups: normal mice, amyloid precursor protein/presenilin 1 (APP/PS1) mice (model group), positive control group (model mice treated with donepezil), high, medium and low LGZG group (model mice treated with 7g/kg/d, 3.5g/kg/d or 1.75g/kg/d LGZG respectively). Water maze results showed that the escape latency and path length of high and medium LGZG groups declined compared to the model mice, the decline degree was dose-dependent. The hippocampal slices of six groups were analyzed by Nissl-staining, Perls\' iron staining and immunofluorescence assay. The results indicated LGZG could restore morphological anomalies and alleviate iron deposition of AD mice, and the GXP4 positive cells increased significantly. The MDA, Fe2+ and GSH were measured by biochemical testing, whose results illustrated that LGZG could normalize MDA, Fe2+ and GSH levels in AD model compared to un-treated APP/PS1 model. The higher dose of LGZG the mice received, the more intensive effects on those levels of molecules. Western blot results showed that LGZG could affect NeuN, AMPK, p53, SLC7A11 and GPX4 levels in the hippocampus of AD model, which was all proteins related to AMPK pathway. In conclusion, LGZG has a neuroprotective effect on AD through AMPK pathway by alleviating oxidative stress and ferroptosis.

BACKGROUND: Physical exercise has been shown to be beneficial for individuals with Alzheimer\'s disease (AD), although the underlying mechanisms are not fully understood.
METHODS: Six-month-old Amyloid precursor protein/Presenilin 1 (APP/PS1) transgenic (Tg) mice and wild-type (Wt) mice were randomly assigned to either a sedentary group (Tg-Sed, Wt-Sed) or an exercise group (Tg-Ex, Wt-Ex) undertaking a 12-week, moderate-intensity treadmill running program. Consequently, all mice were tested for memory function and amyloid β (Aβ) levels and phosphorylation of tau and protein kinase B (Akt)/glycogen synthase kinase-3 (GSK3) were examined in tissues of both the cortex and hippocampus.
RESULTS: Tg-Sed mice had severely impaired memory, higher levels of Aβ, and increased phosphorylation of tau, GSK3α tyrosine279, and GSK3β tyrosine216, but less phosphorylation of GSK3α serine21, GSK3β serine9, and Akt serine473 in both tissues than Wt-Sed mice in respective tissues. Tg-Ex mice showed significant improvement in memory function along with lower levels of Aβ and less phosphorylation of tau (both tissues), GSK3α tyrosine279 (both tissues), and GSK3β tyrosine216 (hippocampus only), but increased phosphorylation of GSK3α serine21 (both tissues), GSK3β serine9 (hippocampus only), and Akt serine473 (both tissues) compared with Tg-Sed mice in respective tissues.
CONCLUSIONS: Moderate-intensity aerobic exercise is highly effective in improving memory function in 9-month-old APP/PS1 mice, most likely through differential modulation of GSK3α/β phosphorylation in the cortex and hippocampus.

Autophagy is a highly conserved catabolic mechanism by which unnecessary or dysfunctional cellular components are removed. The dysregulation of autophagy has been implicated in various neurodegenerative diseases, including Alzheimer\'s disease (AD). Understanding the molecular mechanism(s)/molecules that influence autophagy may provide important insights into developing therapeutic strategies against AD and other neurodegenerative disorders. Engulfment adaptor phosphotyrosine-binding domain-containing protein 1 (GULP1) is an adaptor that interacts with amyloid precursor protein (APP) to promote amyloid-β peptide production via an unidentified mechanism. Emerging evidence suggests that GULP1 has a role in autophagy. Here, we show that GULP1 is involved in autophagy through an interaction with autophagy-related 14 (ATG14), which is a regulator of autophagosome formation. GULP1 potentiated the stimulatory effect of ATG14 on autophagy by modulating class III phosphatidylinositol 3-kinase complex 1 (PI3KC3-C1) activity. The effect of GULP1 is attenuated by a GULP1 mutation (GULP1m) that disrupts the GULP1-ATG14 interaction. Conversely, PI3KC3-C1 activity is enhanced in cells expressing APP but not in those expressing an APP mutant that does not bind GULP1, which suggests a role of GULP1-APP in regulating PI3KC3-C1 activity. Notably, GULP1 facilitates the targeting of ATG14 to the endoplasmic reticulum (ER). Moreover, the levels of both ATG14 and APP are elevated in the autophagic vacuoles (AVs) of cells expressing GULP1, but not in those expressing GULP1m. APP processing is markedly enhanced in cells co-expressing GULP1 and ATG14. Hence, GULP1 alters APP processing by promoting the entry of APP into AVs. In summary, we unveil a novel role of GULP1 in enhancing the targeting of ATG14 to the ER to stimulate autophagy and, consequently, APP processing.

OBJECTIVE: To explore the pathogenesis of Alzheimer\'s disease (AD), the potential targets and signaling pathways of ginsenoside Rg1 against AD were investigated by network pharmacology.
METHODS: Ginsenoside Rg1 targets were identified through PubChem, PharmMapper, and Uniprot databases, while the GeneCards database was used to examine the respective targets of amyloid precursor protein (APP) and AD. Then, the common targets between ginsenoside Rg1 and APP were explored by the Venny tool, the interaction network diagram between the active components and the targets was built via Cytoscape software, as well as GO enrichment and KEGG pathway annotation analysis were performed. Furthermore, genes associated with ferroptosis were found by the GeneCards and FerrDb databases. Besides, the connection among ginsenoside Rg1, APP, ferroptosis, and AD was predicted and analyzed. Finally, the effects of ginsenosides Rg1 and liproxstain-1 on the proliferation and differentiation of APP/PS1 mice were evaluated by immunohistochemistry.
RESULTS: Ginsenoside Rg1, APP, ferroptosis, and AD had 12 hub genes. GO enrichment and KEGG pathway annotation analysis showed that EGFR, SRC, protein hydrolysis, protein phosphorylation, the Relaxin pathway, and the FoxO signaling pathway play an important role in the potential mechanism of ginsenoside Rg1\'s under regulation of ferroptosis anti-AD through the modulation of APP-related signaling pathways. The APP/PS1 mice experiment verified that ginsenosides Rg1 and liproxstain-1 can promote the proliferation and differentiation.
CONCLUSIONS: Ginsenoside Rg1, APP and ferroptosis may act on EGFR, SRC, the Relaxin and FoxO signaling pathways to regulate protein metabolism, protein phosphorylation and other pathways to improve AD symptoms.