This study investigated the mechanism of Danggui Shaoyao Powder(DSP) against mitophagy in rat model of Alzheimer's disease(AD) induced by streptozotocin(STZ) based on PTEN induced putative kinase 1(PINK1)-Parkin signaling pathway. The AD rat model was established by injecting STZ into the lateral ventricle, and the rats were divided into normal group, model group, DSP low-dose group(12 g·kg~(-1)·d~(-1)), DSP medium-dose group(24 g·kg~(-1)·d~(-1)), and DSP high-dose group(36 g·kg~(-1)·d~(-1)). Morris water maze test was used to detect the learning and memory function of the rats, and transmission electron microscopy and immunofluorescence were employed to detect mitophagy. The protein expression levels of PINK1, Parkin, LC3BⅠ/LC3BⅡ, and p62 were assayed by Western blot. Compared with the normal group, the model group showed a significant decrease in the learning and memory function(P<0.01), reduced protein expression of PINK1 and Parkin(P<0.05), increased protein expression of LC3BⅠ/LC3BⅡ and p62(P<0.05), and decreased occurrence of mitophagy(P<0.01). Compared with the model group, the DSP medium-and high-dose groups notably improved the learning and memory ability of AD rats, which mainly manifested as shortened escape latency, leng-thened time in target quadrants and elevated number of crossing the platform(P<0.05 or P<0.01), remarkably activated mitophagy(P<0.05), up-regulated the protein expression of PINK1 and Parkin, and down-regulated the protein expression of LC3BⅠ/LC3BⅡ and p62(P<0.05 or P<0.01). These results demonstrated that DSP might promote mitophagy mediated by PINK1-Parkin pathway to remove damaged mitochondria and improve mitochondrial function, thereby exerting a neuroprotective effect.
Rats ; Animals ; Mitophagy ; Alzheimer Disease/genetics* ; Powders ; Protein Kinases/metabolism* ; Ubiquitin-Protein Ligases/metabolism*

Triggering receptor expressed on myeloid cells 2 (TREM2) is a membrane receptor on myeloid cells and plays an important role in the body's immune defense. Recently, TREM2 has received extensive attention from researchers, and its activity has been found in Alzheimer's disease, neuroinflammation, and traumatic brain injury. The appearance of TREM2 is usually accompanied by changes in apolipoprotein E (ApoE), and there has been a lot of research into their structure, as well as the interaction mode and signal pathways involved in them. As two molecules with broad and important roles in the human body, understanding their correlation may provide therapeutic targets for certain diseases. In this article, we reviewed several diseases in which TREM2 and ApoE are synergistically involved in the development. We further discussed the positive or negative effects of the TREM2-ApoE pathway on nervous system immunity and inflammation.
Humans ; Alzheimer Disease/metabolism* ; Apolipoproteins E/genetics* ; Microglia/metabolism* ; Myeloid Cells/metabolism* ; Signal Transduction ; Neuroinflammatory Diseases

This study aimed to investigate the mechanism of Psoraleae Fructus in improving the learning and memory ability of APP/PS1 mice by serum metabolomics, screen the differential metabolites of Psoraleae Fructus on APP/PS1 mice, and reveal its influence on the metabolic pathway of APP/PS1 mice. Thirty 3-month-old APP/PS1 mice were randomly divided into a model group and a Psoraleae Fructus extract group, and another 15 C57BL/6 mice of the same age were assigned to the blank group. The learning and memory ability of mice was evaluated by the Morris water maze and novel object recognition tests, and metabolomics was used to analyze the metabolites in mouse serum. The results of the Morris water maze test showed that Psoraleae Fructus shortened the escape latency of APP/PS1 mice(P<0.01), and increased the number of platform crossing and residence time in the target quadrant(P<0.01). The results of the novel object recognition test showed that Psoraleae Fructus could improve the novel object recognition index of APP/PS1 mice(P<0.01). Eighteen differential metabolites in serum were screened out by metabolomics, among which the levels of arachidonic acid, tryptophan, and glycerophospholipid decreased after drug administration, while the levels of glutamyltyrosine increased after drug administration. The metabolic pathways involved included arachidonic acid metabolism, glycerophospholipid metabolism, tryptophan metabolism, linoleic acid metabolism, α-linolenic acid metabolism, and glycerolipid metabolism. Therefore, Psoraleae Fructus can improve the learning and memory ability of APP/PS1 mice, and its mechanism may be related to the effects in promoting energy metabolism, reducing oxidative damage, protecting central nervous system, reducing neuroinflammation, and reducing Aβ deposition. This study is expected to provide references for Psoraleae Fructus in the treatment of Alzheimer's disease(AD) and further explain the mechanism of Psoraleae Fructus in the treatment of AD.
Mice ; Animals ; Amyloid beta-Protein Precursor/genetics* ; Mice, Transgenic ; Arachidonic Acid ; Tryptophan ; Mice, Inbred C57BL ; Alzheimer Disease/genetics* ; Maze Learning ; Glycerophospholipids ; Disease Models, Animal ; Amyloid beta-Peptides/metabolism*

The present study aimed to investigate the protective effect and underlying mechanism of Platycladi Semen oil(SP) on Aβ_(25-35)-induced brain injury in mice to provide a theoretical basis for the clinical treatment of Alzheimer's disease(AD). Male Kunming(KM) mice were randomly divided into a control group, a model group(brain injection of Aβ_(25-35), 200 μmol·L~(-1), 0.15 μL·g~(-1)), a positive drug group(donepezil, 10 mg·kg~(-1)), and low-and high-dose SP groups(0.5 and 1 mL·kg~(-1)). Learning and memory ability, neuronal damage, levels of Aβ_(1-42)/Aβ_(1-40), p-Tau, related indicators of apoptosis and oxidative stress, and immune cells, and protein and mRNA expression related to the sphingosine kinase 1(SPHK1)/sphingosine-1-phosphate(S1P)/sphingosine-1-phosphate receptor 5(S1PR5) signaling pathway of mice in each group were determined. In addition, compounds in SP were analyzed by gas chromatography-mass spectrometry(GC-MS). The mechanism of SP against AD was investigated by network pharmacology, 16S rDNA gene sequencing for gut microbiota(GM), and molecular docking techniques. The results showed that SP could improve the learning and memory function of Aβ_(25-35)-induced mice, reduce hippocampal neuronal damage, decrease the levels of Aβ_(1-42)/Aβ_(1-40), p-Tau, and indicators related to apoptosis and oxidative stress in the brain, and maintain the homeostasis of immune cells and GM. Network pharmacology and sequencing analysis for GM showed that the therapeutic effect of SP on AD was associated with the sphingolipid signaling pathway. Meanwhile,(Z,Z,Z)-9,12,15-octadecatrienoic acid and(Z,Z)-9,12-octadecadienoic acid, the components with the highest content in SP, showed good binding activity to SPHK1 and S1PR5. Therefore, it is inferred that SP exerts anti-apoptosis and antioxidant effects by regulating GM and inhibiting SPHK1/S1P/S1PR5 pathway, thereby improving brain injury induced by Aβ_(25-35) in mice. Moreover,(Z,Z,Z)-9,12,15-octadecatrienoic acid and(Z,Z)-9,12-octadecadienoic acid may be the material basis for the anti-AD effect of SP.
Mice ; Animals ; Male ; Semen/metabolism* ; Gastrointestinal Microbiome ; Network Pharmacology ; Linoleic Acid ; Molecular Docking Simulation ; Alzheimer Disease/genetics* ; Brain Injuries

This study aimed to explore the possible effect of Xixin Decoction(XXD) on the learning and memory ability of Alzheimer's disease(AD) model senescence-accelerated mouse-prone 8(SAMP8) and the related mechanism in enhancing neuroprotective effect and reducing neuroinflammation. Forty SAMP8 were randomly divided into a model group(10 mL·kg~(-1)·d~(-1)), a probiotics group(0.39 g·kg~(-1)·d~(-1)), a high-dose group of XXD granules(H-XXD, 5.07 g·kg~(-1)·d~(-1)), a medium-dose group of XXD granules(M-XXD, 2.535 g·kg~(-1)·d~(-1)), and a low-dose group of XXD granules(L-XXD, 1.267 5 g·kg~(-1)·d~(-1)). Eight senescence-accelerated mouse-resistant 1(SAMR1) of the same age and strain were assigned to the control group(10 mL·kg~(-1)·d~(-1)). After ten weeks of intragastric administration, the Morris water maze was used to test the changes in spatial learning and memory ability of mice after treatment. Meanwhile, immunofluorescence staining was used to detect the positive expression of receptor for advanced glycation end products(AGER), Toll-like receptor 1(TLR1), and Toll-like receptor 2(TLR2) in the hippocampal CA1 region of mice. Western blot was employed to test the protein expression levels of silencing information regulator 2 related enzyme 1(SIRT1), AGER, TLR1, and TLR2 in the hippocampus of mice. Enzyme linked immunosorbent assay(ELISA) was applied to assess the levels of Aβ_(1-42) in the hippocampus of mice and the levels of nuclear factor κB p65(NF-κB p65), NOD-like receptor protein 3(NLRP3), tumor necrosis factor-α(TNF-α), and interleukin-1β(IL-1β) in the serum and hippocampus of mice. Compared with the model group, XXD significantly improved the spatial learning and memory ability of SAMP8, increased the expression of neuroprotective factors in the hippocampus, decreased the levels of neuroinflammatory factors, and inhibited the expression of Aβ_(1-42). In particular, H-XXD significantly increased the expression of SIRT1 in the hippocampus of mice, reduced the expression levels of NF-κB p65, NLRP3, TNF-α, and IL-1β in the serum and hippocampus of mice, and decreased the expression of AGER, TLR1, and TLR2 in the hippocampus of mice(P<0.05 or P<0.01). XXD may improve the spatial learning and memory ability of AD model SAMP8 by enhancing the neuroprotective effect and inhibiting neuroinflammation.
Humans ; Neuroprotective Agents/therapeutic use* ; Sirtuin 1/metabolism* ; Toll-Like Receptor 2/metabolism* ; NF-kappa B/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Neuroinflammatory Diseases ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Toll-Like Receptor 1/metabolism* ; Alzheimer Disease/genetics* ; Hippocampus

Objective To explore the effect of knocking down Rho-associated coiled-coil kinase (ROCK2) gene on the cognitive function of amyloid precursor protein/presenilin-1 (APP/PS1) double transgenic mice and its mechanism. Methods APP/PS1 double transgenic mice were randomly divided into AD model group (AD group), ROCK2 gene knock-down group (shROCK2 group), ROCK2 gene knock-down control group (shNCgroup), and wild-type C57BL/6 mice of the same age served as the wild-type control (WT group). Morris water maze and Y maze were employed to test the cognitive function of mice. Neuron morphology was detected by Nissl staining. Immunofluorescence histochemical staining was used to detect the expression of phosphorylated dynamin-related protein 1 (p-Drp1) and mitochondrial fusion 1 (Mfn1). Western blot analysis was used to detect the expression ROCK2, cleaved-caspase-3 (c-caspase-3), B-cell lymphoma 2 (Bcl2), Bcl2-related protein X (BAX), p-Drp1, mitochondrial fission 1 (Fis1), optic atrophy 1 (OPA1), Mfn1 and Mfn2. Results Compared with AD group mice, the expression of ROCK2 in shROCK2 group mice was significantly reduced; the cognitive function was significantly improved with the number of neurons in the hippocampal CA3 and DG areas increasing, and nissl bodies were deeply stained; the expression of c-caspase-3 and BAX was decreased, while the expression of Bcl2 was increased; the expression of mitochondrial division related proteins p-Drp1 and Fis1 were decreased, while the expression of mitochondrial fusion-related proteins OPA1, Mfn1 and Mfn2 were increased. Conclusion Knock-down of ROCK2 gene can significantly improve the cognitive function and inhibit the apoptosis of nerve cells of APP/PS1 mice. The mechanism may be related to promoting mitochondrial fusion and inhibiting its division.
Animals ; Mice ; Alzheimer Disease/pathology* ; Amyloid beta-Peptides/metabolism* ; Amyloid beta-Protein Precursor ; Apoptosis/genetics* ; bcl-2-Associated X Protein ; Caspase 3 ; Cognition ; Disease Models, Animal ; Mice, Inbred C57BL ; Mice, Transgenic ; Mitochondrial Dynamics/genetics*

Alzheimer Disease/genetics* ; Animals ; Apolipoprotein E4/metabolism* ; Gene-Environment Interaction ; Hippocampus/metabolism* ; Male ; Noise/adverse effects* ; Rats

Objective: To uncover the time-dependent expression pattern of ptk2b gene and ptk2b-encoded protein, protein tyrosine kinase 2 beta(PTK2B), in the brain tissues of transgenic animal models of Alzheimer's disease (AD) and its relationship with the levels of Aβ_1-42, phosphorylation of Tau (p-Tau) and low density lipoprotein receptor-related protein-1(LRP-1) in blood and brain tissues. Methods: In this study, 5-, 10- and 15-month-old APPswe/PS1dE9 double-transgenic mice harboring the genotype of AD confirmed by the gene test were divided into the 5-, 10- and 15-month-old experiment groups, and simultaneously, age-matched C57BL/6J mice were placed into the corresponding control groups, with 8 mice in each group. All mice were subjected to the Morris Water Maze for test of cognitive and behavioral ability. Expression profiles of PTK2B, Aβ_1-42, p-Tau/Tau and LRP-1 in the hippocampus or blood of mice were quantified by using the immunohistochemistry staining, Western blot or enzyme-linked immunosorbent assay (ELISA), while the mRNA expression of ptk2b in the hippocampus was quantified by using the real-time quantitative polymerase chain reaction (qRT-PCR). Results: Results of experiment groups demonstrated that as mice aged, the expression levels of PTK2B, ptk2b mRNA, Aβ_1-42 and p-Tau/Tau in the hippocampus were increased, and the expression of LRP-1 was decreased gradually. While in the blood, the level of Aβ_1-42 was decreased, and the cognitive and behavioral ability was decreased in an age-dependent manner (all P＜ 0.05). However, comparisons among the control groups, only the age-dependent downregulation of LRP-1 were observed in hippocampus(P＜0.05), but other indicators had no significant differences (P＞0.05). Conclusion: In the hippocampus of APP/PS1 double-transgenic mice, the expressions of PTK2B, Aβ_1-42 and p-Tau/Tau are upregulated, LRP-1 is downregulated, while cognitive and behavioral ability is decreased, and such changes are presented in a time-dependent manner.
Alzheimer Disease/metabolism* ; Amyloid beta-Peptides ; Amyloid beta-Protein Precursor/genetics* ; Animals ; Focal Adhesion Kinase 2/metabolism* ; Hippocampus/metabolism* ; Low Density Lipoprotein Receptor-Related Protein-1 ; Maze Learning ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; RNA, Messenger

Objective To study the effects of TYRO protein kinase-binding protein (TYROBP) deficiency on learning behavior, glia activation and pro-inflammatory cycokines, and Tau phosphorylation of a new Alzheimer's disease (AD) mouse model carrying a PSEN1 p.G378E mutation.Methods A new AD mouse model carrying PSEN1 p.G378E mutation was built based on our previously found AD family which might be ascribed to the PSEN1 mutation, and then crossed with TYROBP deficient mice to produce the heterozygous hybrid mice (PSEN1^G378E/WT; Tyrobp^+/-) and the homozygous hybrid mice (PSEN1^G378E/G378E; Tyrobp^-/-). Water maze test was used to detect spatial learning and memory ability of mice. After the mice were sacrificed, the hippocampus was excised for further analysis. Immunofluorescence was used to identify the cell that expresses TYROBP and the number of microglia and astrocyte. Western blot was used to detect the expression levels of Tau and phosphorylated Tau (p-Tau), and ELISA to measure the levels of pro-inflammatory cytokines. Results Our results showed that TYROBP specifically expressed in the microglia of mouse hippocampus. Absence of TYROBP in PSEN1^G378E mutation mouse model prevented the deterioration of learning behavior, decreased the numbers of microglia and astrocytes, and the levels of interleukin-6, interleukin-1β and tumor necrosis factor-α in the hippocampus (all P < 0.05). The ratios of AT8/Tau5, PHF1/Tau5, pT181/Tau5, pT231/Tau5 and p-ERK/ERK were all higher in homozygous hybrid mice (PSEN1^G378E/G378E; Tyrobp^-/- mice) compared with PSEN1^G378E/G378E mice (all P < 0.05). Conclusions TYROBP deficiency might play a protective role in the modulation of neuroinflammation of AD. However, the relationship between neuroinflammation processes involving microglia and astrocyte activation, and release of pro-inflammatory cytokines, and p-Tau pathology needs further study.
Mice ; Animals ; Alzheimer Disease/genetics* ; Neuroinflammatory Diseases ; Hippocampus/pathology* ; Mutation ; Cytokines/pharmacology* ; Disease Models, Animal ; tau Proteins/pharmacology* ; Amyloid beta-Peptides/metabolism* ; Adaptor Proteins, Signal Transducing/pharmacology*

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease featuring progressive cognitive impairment. Although the etiology of late-onset AD remains unclear, the close association of AD with apolipoprotein E (APOE), a gene that mainly regulates lipid metabolism, has been firmly established and may shed light on the exploration of AD pathogenesis and therapy. However, various confounding factors interfere with the APOE-related AD risk, raising questions about our comprehension of the clinical findings concerning APOE. In this review, we summarize the most debated factors interacting with the APOE genotype and AD pathogenesis, depict the extent to which these factors relate to APOE-dependent AD risk, and discuss the possible underlying mechanisms.
Alzheimer Disease/pathology* ; Apolipoprotein E4/genetics* ; Apolipoproteins E/genetics* ; Genotype ; Humans ; Lipid Metabolism ; Neurodegenerative Diseases ; Risk Factors