Alzheimer's disease (AD) is the most common cause of dementia and is a growing public health challenge. Neuroinflammation has been proposed as a prominent pathological feature of AD and has traditionally been attributed to the innate immune system. However, emerging evidence highlights the involvement of adaptive immunity, particularly T and B lymphocytes, in the neuroinflammatory processes of AD. It remains unclear how adaptive immune responses, originally intended to protect the body, contribute to chronic inflammation and neuronal dysfunction in AD. Here, we review the roles of adaptive immunity, cellular composition, and niches and their contribution to AD development and progression. Notably, we synthesize the crosstalk between adaptive immunity and the innate immune system of the central nervous system (CNS), which is mainly mediated by glial cells and myeloid cells, and their interrelationships with amyloid-β (Aβ)/Tau pathology. We hypothesized that the alterations observed in innate immunity in AD mirror age-related immune alterations, whereas the dysregulation of adaptive immunity contributes more accurately to disease-specific immune responses. Targeting adaptive immunity in the context of neuroinflammation may provide new insights into potential therapeutic strategies designed to modulate immune responses, thereby facilitating the diagnosis, intervention, and treatment of AD.
Alzheimer Disease/metabolism* ; Humans ; Adaptive Immunity/physiology* ; Immunity, Innate/immunology* ; Animals ; Neuroinflammatory Diseases/immunology* ; Inflammation/immunology* ; Amyloid beta-Peptides/metabolism*

Neurodegenerative diseases constitute a group of chronic disorders characterized by the progressive loss of neurons. Major neurodegenerative conditions include Alzheimer's disease, Parkinson's disease, Huntington's disease, frontotemporal lobar degeneration, and amyotrophic lateral sclerosis. Pathologically, these diseases are marked by the accumulation of aggregates formed by pathological proteins such as amyloid-β, tau, α-synuclein, and TAR DNA-binding protein 43. These proteins assemble into amyloid fibrils that undergo prion-like propagation and dissemination, ultimately inducing neurodegeneration. Understanding the biology of these protein aggregates is fundamental to elucidating the pathophysiology of neurodegenerative disorders. In this review, we summarize the molecular mechanisms underlying the aggregation and transmission of pathological proteins, the processes through which these protein aggregates trigger neurodegeneration, and the interactions between different pathological proteins. We also provide an overview of the current diagnostic approaches and therapeutic strategies targeting pathological protein aggregates.
Humans ; Neurodegenerative Diseases/metabolism* ; alpha-Synuclein/metabolism* ; Amyloid beta-Peptides/metabolism* ; tau Proteins/metabolism* ; Protein Aggregation, Pathological/metabolism* ; DNA-Binding Proteins/metabolism* ; Animals ; Protein Aggregates/physiology*

INTRODUCTION: Lecanemab has shown promise in treating early Alzheimer's disease (AD), but its safety and efficacy in Chinese populations remain unexplored. This study aimed to evaluate the safety and 6-month clinical outcomes of lecanemab in Chinese patients with mild cognitive impairment (MCI) or mild AD. METHODS: In this single-arm, real-world study, participants with MCI due to AD or mild AD received biweekly intravenous lecanemab (10 mg/kg). The study was conducted at Hainan Branch, Ruijin Hospital Shanghai Jiao Tong University School of Medicine. Patient enrollment and baseline assessments commenced in November 2023. Safety assessments included monitoring for amyloid-related imaging abnormalities (ARIA) and other adverse events. Clinical and biomarker changes from baseline to 6 months were evaluated using cognitive scales (mini-mental state examination [MMSE], montreal cognitive assessment [MoCA], clinical dementia rating-sum of boxes [CDR-SB]), plasma biomarker analysis, and advanced neuroimaging. RESULTS: A total of 64 patients were enrolled in this ongoing real-world study. Safety analysis revealed predominantly mild adverse events, with infusion-related reactions (20.3%, 13/64) being the most common. Of these, 69.2% (9/13) occurred during the initial infusion and 84.6% (11/13) did not recur. ARIA-H (microhemorrhages/superficial siderosis) and ARIA-E (edema/effusion) were observed in 9.4% (6/64) and 3.1% (2/64) of participants, respectively, with only two symptomatic cases (one ARIA-E presenting with headache and one ARIA-H with visual disturbances). After 6 months of treatment, cognitive scores remained stable compared to baseline (MMSE: 22.33 ± 5.58 vs . 21.27 ± 4.30, P = 0.733; MoCA: 16.38 ± 6.67 vs . 15.90 ± 4.78, P = 0.785; CDR-SB: 2.30 ± 1.65 vs . 3.16 ± 1.72, P = 0.357), while significantly increasing plasma amyloid-β 42 (Aβ42) (+21.42%) and Aβ40 (+23.53%) levels compared to baseline. CONCLUSIONS: Lecanemab demonstrated a favorable safety profile in Chinese patients with early AD. Cognitive stability and biomarker changes over 6 months suggest potential efficacy, though high dropout rates and absence of a control group warrant cautious interpretation. These findings provide preliminary real-world evidence for lecanemab's use in China, supporting further investigation in larger controlled studies. REGISTRATION ClinicalTrials.gov , NCT07034222.
Humans ; Alzheimer Disease/drug therapy* ; Male ; Female ; Aged ; Middle Aged ; Cognitive Dysfunction/drug therapy* ; Aged, 80 and over ; Amyloid beta-Peptides/metabolism* ; Biomarkers ; East Asian People

Alzheimer's disease (AD), a prototypical neurodegenerative disorder, encompasses multifaceted pathological processes. As pivotal cellular structures within the central nervous system, ion channels play critical roles in regulating neuronal excitability, synaptic transmission, and neurotransmitter release. Extensive research has revealed significant alterations in the expression and function of ion channels in AD, implicating an important role of ion channels in the pathogenesis of abnormal Aβ deposition, neuroinflammation, oxidative stress, and disruptions in calcium homeostasis and neural network functionality. This review systematically summarizes the crucial roles and underlying mechanisms of ion channels in the onset and progression of AD, highlighting how these channel abnormalities contribute to AD pathophysiology. We also discuss the therapeutic potential of ion channel modulation in AD treatment, emphasizing the importance of addressing multifactorial nature and heterogeneity of AD. The development of multi-target drugs and precision therapies is proposed as a future direction of scientific research.
Alzheimer Disease/therapy* ; Humans ; Ion Channels/physiology* ; Oxidative Stress ; Animals ; Amyloid beta-Peptides/metabolism* ; Synaptic Transmission ; Calcium/metabolism*

The hippocampus, a major component of the limbic system, is the most important region related to emotion regulation and memory processing. Cognitive impairment and depressive symptoms observed in Alzheimer's disease (AD) patients may be attributed to hippocampal damage caused by amyloid β-protein (Aβ). Our previous studies have demonstrated that a steroid sulfatase inhibitor DU-14 can enhance hippocampal synaptic plasticity and spatial memory abilities in a chronic AD murine model by counteracting the toxic effects of Aβ. However, limited experimental evidence exists regarding the efficacy of steroid sulfatase inhibitor on depressive symptoms in AD animal models. In this study, we investigated the effects of DU-14 on depressive symptoms and theta-band neuronal oscillations in rats with intrahippocampal injection of Aβ_1-42 using various behavioral tests such as sucrose preference test, tail suspension test, forced swimming test, and in vivo hippocampal local field potential (LFP) recording. The results demonstrated that, in comparison to the control group: (1) rats in the Aβ group exhibited a decrease in sucrose preference, indicating a loss of interest in pleasurable activities; (2) rats in the Aβ group displayed aggravated depressive-like behavior characterized by prolonged immobility time during tail suspension and forced swimming tests; (3) Aβ disrupted the induction of theta rhythm via tail pinch stimulation, and resulted in a significant reduction in peak power of theta rhythm. In contrast to the Aβ group, pretreatment with DU-14 resulted in: (1) a significant improvement in Aβ-induced anhedonia, as evidenced by increased sucrose preference; (2) significant alleviation of Aβ-induced despair and depressive-like behaviors, reflected by reduced immobility time during tail suspension and forced swimming tests; (3) successful mitigation of Aβ-mediated inhibition on bilateral hippocampal theta rhythm. These findings indicate that steroid sulfatase inhibitor DU-14 can counteract neurotoxicity induced by Aβ, and prevent Aβ-induced depressive-like behavior and suppression of theta rhythm.
Animals ; Amyloid beta-Peptides/toxicity* ; Rats ; Depression/physiopathology* ; Theta Rhythm/drug effects* ; Hippocampus/physiopathology* ; Male ; Rats, Sprague-Dawley ; Alzheimer Disease/physiopathology* ; Steryl-Sulfatase/antagonists & inhibitors* ; Peptide Fragments ; Behavior, Animal/drug effects*

Alzheimer's disease (AD) is the commonest neurodegenerative disease that causes memory decline, cognitive dysfunction and behavior disorders in the aged people. Primary pathological hallmarks of AD include amyloid-β (Aβ), neurofibrillary tangles (NFTs), gliosis, and neuronal loss. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels have important physiological functions, especially in aspects of controlling the resting membrane potential, pacemaker activity, memory formation, sleep and arousal. This article reviews the structure, distribution, regulation of HCN channels and the role of HCN channels in the pathological mechanisms of AD, aiming to provide drug therapeutic targets for the prevention and treatment of AD.
Humans ; Alzheimer Disease/physiopathology* ; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels/physiology* ; Animals ; Amyloid beta-Peptides/metabolism*

To study the ameliorative effect of Eucommiae Cortex extract on spatial learning disabilities in APP/PS1 double-transgenic mice and explore its relationship with estrogen receptor β(ERβ)/c-Jun N-terminal kinase(JNK) signaling pathway, sixty 3-month-old male APP/PS1 mice were randomly divided into a model group, an anti-brain failure capsule group(0.585 g·kg~(-1)), a donepezil hydrochloride group(0.65 mg·kg~(-1)), and a Eucommiae Cortex extract group(1.3 g·kg~(-1)), and 15 C57BL/6 mice of the same genetic background were set as WT control group. The learning and memory ability of mice was assessed by the Morris water maze test(MWM), the passive avoidance test(PAT), and the novel object recognition test(NOR). The histomorphological and cellular ultrastructural features of the hippocampal region of the mice were observed by hematoxylin-eosin(HE) staining and transmission electron microscopy(TEM); the molecular docking validation of the key active ingredients and the key targets was performed by using AutoDock Vina software, and the immunohistochemical method(IHC) was used to detect the ERβ expression in the dentate gyrus(DG) area of mouse hippocampus. Western blot(WB) was utilized to detect the expression of ERβ, p-JNK, and JNK in mouse hippocampal area. Compared with those in the WT control group, the results of behavioral experiments showed that the latency of the mice in the model group was significantly increased, the number of platform traversals, and the target quadrant residence time were significantly decreased in the MWM. The evasion latency was significantly reduced, and the number of errors was significantly increased in the PAT. The index of recognition of novel objects was significantly reduced in the NOR. The results of HE staining indicated that the hippocampal area of mice in the model group showed a decrease in the number of neurons, disorganization of pyramidal cell arrangement, nucleus consolidation, and other changes. TEM results showed that some neuronal nuclei in the hippocampal area had a consolidated state, slightly thickened and aberrant nuclear membranes, and fewer intracytoplasmic nidus bodies; the IHC results showed that the expression of ERβ in the hippocampal DG area of the mice was reduced. The WB results showed that the ERβ expression in the hippocampal tissue was decreased, and the p-JNK/JNK level was elevated. Compared with the model group, the Eucommiae Cortex extract group showed a significant decrease in latency, and increase in number of platform traversals and target quadrant residence time in the MWM, a significant increase in evasion latency and decrease in number of errors in the PAT, and a significant increase in the index of recognition of novel objects in the NOR. In addition, there was an increase in the number of neurons in the hippocampal area of mice. The pyramidal cells tended to be arranged in an orderly manner; the nuclei of neurons in the hippocampal area were in a better state; the expression of ERβ in the hippocampal DG area of the mice was elevated; the expression of ERβ in the hippocampal tissue was elevated, and the level of p-JNK/JNK was reduced. The effects of donepezil hydrochloride group and anti-brain failure capsule on APP/PS1 mice in terms of behavioral, HE, and TEM indexes were similar to those of Eucommiae Cortex extract, and there was no significant difference between donepezil hydrochloride group and the model group in IHC and WB experiments, and the results of molecular docking indicated that the estrogen-like components in Eucommiae Cortex extract were tightly bound to ERβ. In conclusion, the binding of Eucommiae Cortex extract to estrogen receptors, regulation of ERβ expression, and activation of ERβ/JNK signaling pathway may be one of the key mechanisms by which it improves the learning and memory ability of APP/PS1 mice.
Animals ; Male ; Mice ; Mice, Transgenic ; Memory/drug effects* ; Mice, Inbred C57BL ; Estrogen Receptor beta/genetics* ; Eucommiaceae/chemistry* ; Alzheimer Disease/psychology* ; Amyloid beta-Protein Precursor/metabolism* ; Presenilin-1/metabolism* ; Humans ; MAP Kinase Signaling System/drug effects* ; Drugs, Chinese Herbal/administration & dosage* ; Hippocampus/metabolism* ; Maze Learning/drug effects* ; Learning/drug effects*

This study aims to investigate the therapeutic effect and mechanism of Daotan Xixin Decoction on APP/PS1 mice. Twelve APP/PS1 male mice were randomized into four groups: APP/PS1 and low-, medium-, and high-dose Daotan Xixin Decoction. Three C57BL/6 wild-type mice were used as the control group. The learning and memory abilities of mice in each group were examined by the Morris water maze test. The pathological changes of hippocampal nerve cells were observed by hematoxylin-eosin staining and Nissl staining. Immunohistochemistry was employed to detect the expression of β-amyloid(Aβ)_(1-42) in the hippocampal tissue. The high-dose Daotan Xixin Decoction group with significant therapeutic effects and the model group were selected for high-throughput sequencing. The differentially expressed gene(DEG) analysis, Gene Ontology(GO) analysis, Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis, and Gene Set Variation Analysis(GSVA) were performed on the sequencing results. RT-qPCR and Western blot were conducted to determine the mRNA and protein levels, respectively, of some DEGs. Compared with the APP/PS1 group, Daotan Xixin Decoction at different doses significantly improved the learning and memory abilities of APP/PS1 mice, ameliorated the neuropathological damage in the CA1 region of the hippocampus, increased the number of neurons, and decreased the deposition of Aβ_(1-42) in the brain. A total of 1 240 DEGs were screened out, including 634 genes with up-regulated expression and 606 genes with down-regulated expression. The GO analysis predicted the biological processes including RNA splicing and protein folding, the cellular components including spliceosome complexes and nuclear spots, and the molecular functions including unfolded protein binding and heat shock protein binding. The KEGG pathway enrichment analysis revealed the involvement of neurodegenerative disease pathways, amyotrophic lateral sclerosis, and splicing complexes. Further GSVA pathway enrichment analysis showed that the down-regulated pathways involved nuclear factor-κB(NF-κB)-mediated tumor necrosis factor-α(TNF-α) signaling pathway, UV response, and unfolded protein response, while the up-regulated pathways involved the Wnt/β-catenin signaling pathway. The results of RT-qPCR and Western blot showed that compared with the APP/PS1 group, Daotan Xixin Decoction at different doses down-regulated the mRNA and protein levels of signal transducer and activator of transcription 3(STAT3), NF-κB, and interleukin-6(IL-6) in the hippocampus. In conclusion, Daotan Xixin Decoction can improve the learning and memory abilities of APP/PS1 mice by regulating the STAT3/NF-κB/IL-6 signaling pathway.
Animals ; Drugs, Chinese Herbal/administration & dosage* ; Mice ; Male ; Alzheimer Disease/metabolism* ; Computational Biology ; Mice, Inbred C57BL ; High-Throughput Nucleotide Sequencing ; Amyloid beta-Protein Precursor/metabolism* ; Hippocampus/metabolism* ; Mice, Transgenic ; Presenilin-1/metabolism* ; Humans ; Memory/drug effects* ; Maze Learning/drug effects* ; Amyloid beta-Peptides/genetics* ; Disease Models, Animal

The aim of this study is to investigate the regulation of Kaixin San-medicated serum(KXS-MS) on autophagy induced by Aβ_(25-35) in SH-SY5Y cells. The SH-SY5Y cell model of Aβ_(25-35)(25 μmol·L~(-1))-induced injury was established, and different concentrations of KXS-MS were added into the culture media of cells, which were then incubated for 24 h. Cell viability was measured by the methyl thiazolyl tetrazolium(MTT) assay. The protein levels of microtubule-associated protein 1 light chain 3(LC3)Ⅰ, LC3Ⅱ, protein kinase B(Akt), p-Akt, mammalian target of rapamycin(mTOR), and p-mTOR were assessed by Western blot. Furthermore, the combination of rapamycin(Rapa)/3-methyladenine(3-MA) and low concentration of KXS-MS was added to the culture medium of SH-SY5Y cells injured by Aβ_(25-35), and the cell viability and the expression levels of the above proteins were determined. The results showed that Aβ_(25-35) decreased the cell viability, up-regulated the expression levels of LC3Ⅱ and LC3Ⅱ/LC3Ⅰ, and down-regulated the expression levels of p-Akt, p-mTOR, p-Akt/Akt, and p-mTOR/mTOR. Compared with the Aβ_(25-35) model group, KXS-MS treatment attenuated Aβ_(25-35)-induced injury and enhanced the survival of SH-SY5Y cells. Meanwhile, KXS-MS down-regulated the LC3Ⅱ/LC3Ⅰ level and up-regulated the p-Akt/Akt and p-mTOR/mTOR levels. Compared with the low-concentration KXS-MS group, Rapa did not affect the cell survival and the levels of p-Akt and p-Akt/Akt, while it up-regulated the levels of LC3Ⅱ and LC3Ⅱ/LC3Ⅰ and down-regulated the levels of p-mTOR and p-mTOR/mTOR. 3-MA significantly reduced the cell survival rate and p-Akt, p-Akt/Akt level in the KXS-MS group, while it had no significant effect on the levels of LC3Ⅱ, LC3Ⅱ/LC3Ⅰ, p-mTOR, and p-mTOR/mTOR. The above results indicate that KXS-MS exhibits protective effects against Aβ_(25-35)-induced damage in SH-SY5Y cells by up-regulating Akt/mTOR activity to inhibit autophagy.
Humans ; Autophagy/drug effects* ; TOR Serine-Threonine Kinases/genetics* ; Amyloid beta-Peptides/toxicity* ; Proto-Oncogene Proteins c-akt/genetics* ; Drugs, Chinese Herbal/pharmacology* ; Cell Line, Tumor ; Cell Survival/drug effects* ; Peptide Fragments/toxicity* ; Microtubule-Associated Proteins/genetics*

This study explored the action mechanism of Jiawei Xionggui Decoction in the treatment of Alzheimer's disease(AD) by integrating mouse brain tissue metabolomics and network pharmacology. Six-month-old amyloid precursor protein/presenilin 1(APP/PS1) mice were selected and divided into the APP/PS1 group and Jiawei Xionggui Decoction intervention group, with age-matched C57BL/6 mice serving as controls. Cognitive abilities and pathological damage in the mice were observed. Gas chromatography-mass spectrometry/mass spectrometry(GC-MS/MS) technology was utilized to analyze the metabolic profiles of mice brain tissue. Differential metabolites were screened, and relevant metabolic pathways were enriched. Network pharmacology was adopted to screen the active components of Jiawei Xionggui Decoction, so as to construct a protein-protein interaction network of its core targets for AD treatment and conduct Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analysis of potential targets for Jiawei Xionggui Decoction in treating AD. Finally, a "metabolite-reaction-enzyme-gene" network was constructed for combined analysis of metabolomics and network pharmacology. The results showed that Jiawei Xionggui Decoction significantly reversed the trends of 18 differential metabolites involved in 15 metabolic pathways such as glyoxylate and dicarboxylate metabolism, glycine, serine, and threonine metabolism, pyruvate metabolism, alanine, aspartate, and glutamate metabolism, and tricarboxylic acid cycle(TCA) in mouse brain tissue. Furthermore, 383 core targets of Jiawei Xionggui Decoction were implicated in pathways like the phosphoinositide 3-kinase(PI3K)/protein kinase B(Akt) signaling pathway and calcium signaling pathway. Overall analysis indicated that energy metabolism, amino acid metabolism, and fatty acid metabolism were crucial metabolic pathways for Jiawei Xionggui Decoction in treating AD. The findings suggest that Jiawei Xionggui Decoction can protect neuronal cells in mouse brain tissue, thus improving cognitive impairment.
Animals ; Drugs, Chinese Herbal/administration & dosage* ; Mice ; Network Pharmacology ; Metabolomics ; Cognitive Dysfunction/genetics* ; Alzheimer Disease/genetics* ; Mice, Inbred C57BL ; Amyloid beta-Protein Precursor/metabolism* ; Male ; Brain/drug effects* ; Humans ; Presenilin-1/metabolism* ; Protein Interaction Maps/drug effects* ; Mice, Transgenic ; Disease Models, Animal