Alzheimer Disease: An Update on Pathobiology and Treatment Strategies

MiR-7a-Klf4 axis as a regulator and therapeutic target of neuroinflammation and ferroptosis in Alzheimer's disease

Neuroinflammation and ferroptosis significantly contribute to neuronal death in Alzheimer's disease (AD) and other neurodegenerative disorders. MicroRNAs (miRNAs) are crucial regulators of these pathological processes. We employed transcriptomic analysis in an APP/PSEN1 Tg AD mouse model to identify dysregulated miRNAs and construct a miRNA-mRNA-pathway network. We discovered increased miR7a expression in the AD brain, targeting Krüppel-like factor 4 (Klf4), a transcriptional factor implicated in Aβ oligomer-induced neuroinflammation and RSL3-induced neuronal ferroptosis. Elevated Klf4 levels in AD mice brains suggest its involvement in AD pathology. The miR-7a mediated silencing of Klf4 alleviates neuroinflammation by modulating NF-κB, iNOS, and NLRP3 pathways, and inhibition of ferroptosis by targeting labile iron levels, GPX4, Nrf2 pathway, and mitochondrial damage. These findings highlight the neuroprotective role of miR-7a and its potential as RNA therapeutic. Pharmacological targeting of the miR-7a-Klf4 axis with blood-brain-barrier (BBB)-permeable compound effectively mitigates neuroinflammation and ferroptosis, suggesting the miR-7a-Klf4 axis as a novel therapeutic target for AD.

GRAPHICAL ABSTRACT

Cerebrospinal fluid LMO4 as a synaptic biomarker linked to Alzheimer's disease pathology and cognitive decline

BackgroundLIM-domain-only 4 (LMO4) is involved in neurodevelopment and synaptic plasticity, but its role in the pathogenesis of Alzheimer's disease (AD) remains unclear.ObjectiveTo investigate the association between cerebrospinal fluid (CSF) LMO4 levels and core AD biomarkers, neurodegeneration, and cognitive decline.MethodsWe included 703 participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Associations between CSF LMO4 and AD biomarkers (Aβ42, Ptau181, amyloid PET) and postmortem neuropathology were evaluated. We also explored cross-sectional and longitudinal associations between CSF LMO4 and neurodegeneration and cognitive function. Receiver operating characteristic (ROC) analysis assessed the diagnostic accuracy of CSF LMO4 in distinguishing Aβ-positive from Aβ-negative participants and amyloid PET-confirmed AD cases. Mediation analysis explored the potential mediating role of CSF LMO4 between Aβ pathology and tau pathology.ResultsLMO4 levels were decreased in participants with abnormal Aβ levels and cognitive impairment. Lower CSF LMO4 levels were associated with increased Aβ and tau pathology, brain atrophy, cognitive decline, and postmortem neuropathology. CSF LMO4 partially mediated the relationship between Aβ and tau pathology and demonstrated acceptable discriminative ability in distinguishing Aβ-positive from Aβ-negative participants and amyloid PET-confirmed AD from non-AD cases.ConclusionsCSF LMO4 plays a crucial role in the pathogenesis and progression of AD and may represent a potential therapeutic target for AD treatment.

The night's watch: Exploring how sleep protects against neurodegeneration

Sleep loss is often regarded as an early manifestation of neurodegenerative diseases given its common occurrence and link to cognitive dysfunction. However, the precise mechanisms by which sleep disturbances contribute to neurodegeneration are not fully understood, nor is it clear why some individuals are more susceptible to these effects than others. This review addresses critical unanswered questions in the field, including whether sleep disturbances precede or result from neurodegenerative diseases, the functional significance of sleep changes during the preclinical disease phase, and the potential role of sleep homeostasis as an adaptive mechanism enhancing resilience against cognitive decline and neurodegeneration.

Exosomes as Biomarkers and Therapeutic Agents in Neurodegenerative Diseases: Current Insights and Future Directions

Neurodegenerative diseases (NDs) like Alzheimer's, Parkinson's, and ALS rank among the most challenging global health issues, marked by substantial obstacles in early diagnosis and effective treatment. Current diagnostic techniques frequently demonstrate inadequate sensitivity and specificity, whilst conventional treatment strategies encounter challenges related to restricted bioavailability and insufficient blood-brain barrier (BBB) permeability. Recently, exosomes-nanoscale vesicles packed with proteins, RNAs, and lipids-have emerged as promising agents with the potential to reshape diagnostic and therapeutic approaches to these diseases. Unlike conventional drug carriers, they naturally traverse the BBB and can deliver bioactive molecules to affected neural cells. Their molecular cargo can influence cell signaling, reduce neuroinflammation, and potentially slow neurodegenerative progression. Moreover, exosomes serve as non-invasive biomarkers, enabling early and precise diagnosis while allowing real-time disease monitoring. Additionally, engineered exosomes, loaded with therapeutic molecules, enhance this capability by targeting diseased neurons and overcoming conventional treatment barriers. By offering enhanced specificity, reduced immunogenicity, and an ability to bypass physiological limitations, exosome-based strategies present a transformative advantage over existing diagnostic and therapeutic approaches. This review examines the multifaceted role of exosomes in NDDs, emphasizing their diagnostic capabilities, intrinsic therapeutic functions, and transformative potential as advanced treatment vehicles.

Studying the effect of Chlamydia trachomatis, Helicobacter pylori, and Varicella zoster microorganisms in stimulating the expression of cytokines TNFα, IFNɤ, TGFβ, IL-10 in Alzheimer and non-Alzheimer patients

OBJECTIVES

This study aimed to use the real-time RT-PCR method to detect the gene expression cytokines IL-10, TNFα, IFN-γ, and TGF-β in the serum of Alzheimer's patients.

METHODS

This study was conducted on 100 serum samples of Alzheimer's patients. DNA extraction was performed on the samples with the Cinnaclone kit and PCR techniques were used to detect the presence of Helicobacter pylori, Chlamydia trachomatis, and Varicella zoster virus. Real-time RT-PCR was performed to measure the expression of TNFα, IFNɤ, TGFβ, and IL-10 genes with a Smobio kit.

RESULTS

The relative changes in the expression of TNFα, IFNɤ, TGFβ, and IL-10 genes were observed in Alzheimer's patients compared to the control samples without microorganisms, and a significant increase was observed (P < 0.05).

CONCLUSION

This study showed that the cytokines TNFα, IFNɤ, TGFβ, and IL-10, have an increase in Alzheimer's patients(P < 0.05). Therefore, the presence of the microorganisms accompanied by the rise and inducing the expression of cytokines compared to the groups without the mentioned microorganisms causes a significant increase in the production of cytokines effective in the occurrence or exacerbation of Alzheimer's disease.

Longan Aril polysaccharides ameliorate cognitive impairment in AD mice via restoration of the immune phagocytosis of microglia

ETHNOPHARMACOLOGICAL RELEVANCE

Alzheimer's disease (AD) belongs to the category of "forgetfulness" or "dementia" in traditional Chinese medicine, and is often caused by deficiency of five zang-viscera. Longan Aril (the aril of Dimocarpus longan Lour., LA) possesses properties beneficial for heart and spleen health, blood nourishment, and mind tranquility, suggesting its potential as a treatment for AD. This study aimed to investigate the therapeutic effects of Longan Aril polysaccharides (LAPs), a primary active constituent of LA, on lipopolysaccharides (LPS) and amyloid β-peptide (Aβ) induced immune tolerance in AD mice. Further, BV2 cells were employed to explore the mechanism of LAPs in improving immune tolerance.

MATERIAL AND METHODS

LAPs were prepared by water extraction and alcohol precipitation. The monosaccharide composition was determined by high-performance liquid chromatography (HPLC). An AD mouse model of immune tolerance was established by intraperitoneal (i.p) injection of LPS combined with intracerebroventricular (ICV) injection of Aβ25-35. The LAPs group mice received LAPs (1.4 g/kg) daily for 40 days. The anti-AD efficacy and mechanism of LAPs in vivo was evaluated by the Y maze, Morris water maze, Degenerating Neurons Stain (FJC staining), hematoxylin-eosin (H&E) staining, Nissl staining, measurements of lactate, tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) secretion levels, immunofluorescence and western blot. Furthermore, the mechanism of LAPs in improving the function of immune-tolerant BV2 cells was explored in vitro using lactic acid kits, ELISA kits, and western blot. The phagocytic function of BV2 cells was evaluated by the fluorescent dye Alexa Fluor 488 labeled Aβ (AF448-Aβ).

RESULTS

LAPs contained five monosaccharides. LAPs improved cognitive function and increased the number of Nissl bodies, lactate secretion, the IL-10 content, the relative fluorescence intensity of the IBA1 and AXL proteins, and the protein expression levels of AXL, Mertk, Glut1, HK2, PI3K, p-Akt/Akt, p-mTOR/mTOR and HIF-1α of immune-tolerant AD mice. LAPs also reduced the TNF-α content, and the protein expression level of CD68 in immune-tolerant AD mice. In vitro, LAPs elevated the IL-10 content and protein expression levels of PI3K, Akt, p-Akt, and HIF-1α, while reducing lactate secretion and the TNF-α content in immune-tolerant BV2 cells. LAPs promoted the phagocytic activity of BV2 cells, and their effects are completely inhibited by 2-DG and partially inhibited by BAY and Rapa.

CONCLUSIONS

LAPs can enhance the cognitive abilities of immune-tolerant AD mice and diminish their pathological damage. The mechanism involves the regulation of glycolysis and the PI3K/Akt/mTOR/HIF-1α signaling pathway to promote microglial immune phagocytosis.

Pathological tau activates inflammatory nuclear factor-kappa B (NF-κB) and pT181-Qβ vaccine attenuates NF-κB in PS19 tauopathy mice

Tau regulates neuronal integrity. In tauopathy, phosphorylated tau detaches from microtubules and aggregates, and is released into the extracellular space. Microglia are the first responders to the extracellular tau, a danger/damage-associated molecular pattern (DAMP), which can be cleared by proteostasis and activate innate immune response gene expression by nuclear factor-kappa B (NF-κB). However, longitudinal NF-κB activation in tauopathies and whether pathological tau (pTau) contributes to NF-κB activity is unknown. Here, we tau oligomers from human Alzheimer's disease brain (AD-TO) activate NF-κB in mouse microglia and macrophages reducing the IκBα via promoting its secretion in the extracellular space. NF-κB activity peaks at 9- and 11-months age in PS19Luc + and hTauLuc + mice, respectively. Reducing pTau via pharmacological (DOX), genetic ( Mapt -/- ) or antibody-mediated neutralization (immunization with pT181-Qβ vaccine) reduces NF-κB activity, and together suggest pTau is a driver of NF-κB and chronic neuroinflammation tauopathies.

Summary

Neuronal tau activates microglial NF-κB constitutively by secreting its inhibitor IκBα. NF-κB activation in PS19Luc + and hTauLuc + mice peaks at 9- and 11-months of age, respectively. Neutralizing pTau with pT181-Qβ vaccine (targeting phosphorylated threonine 181 tau) alleviates NF-κB activity in tauopathy mice.

APOE genotype determines cell-type-specific pathological landscape of Alzheimer's disease

The apolipoprotein E (APOE) gene is the strongest genetic risk modifier for Alzheimer's disease (AD), with the APOE4 allele increasing risk and APOE2 decreasing it compared with the common APOE3 allele. Using single-nucleus RNA sequencing of the temporal cortex from APOE2 carriers, APOE3 homozygotes, and APOE4 carriers, we found that AD-associated transcriptomic changes were highly APOE genotype dependent. Comparing AD with controls, APOE2 carriers showed upregulated synaptic and myelination-related pathways, preserving synapses and myelination at the protein level. Conversely, these pathways were downregulated in APOE3 homozygotes, resulting in reduced synaptic and myelination proteins. In APOE4 carriers, excitatory neurons displayed reduced synaptic pathways similar to APOE3, but oligodendrocytes showed upregulated myelination pathways like APOE2. However, their synaptic and myelination protein levels remained unchanged or increased. APOE4 carriers also showed increased pro-inflammatory signatures in microglia but reduced responses to amyloid-β pathology. These findings reveal APOE genotype-specific molecular alterations in AD across cell types.

Structural insights into human ABCA7-mediated lipid transport

The human ATP-binding cassette (ABC) transporter ABCA7 participates in the lipidation of apolipoprotein ApoE, a commonly recognized risk factor for Alzheimer's disease (AD). How ABCA7 is involved in the molecular pathogenesis of AD remains poorly understood. Using cryoelectron microscopy (cryo-EM), we determined ABCA7 structures in the apo and substrate-bound forms, respectively. Combined with activity assays, we assigned the residues that specifically bind two molecules of phosphatidylserine (PS) that are arranged in a "tail-to-tail" manner. Pull-down assays confirmed that ApoE directly interacts with ABCA7; and moreover, both ATPase and lipid transport activities of ABCA7 were significantly enhanced in the presence of ApoE. We also measured the activities of a familial AD variant and a protective clinically reported variant in the ABCA7 gene. Our findings not only give structural insights into ABCA7-mediated PS translocation, but we also provide first biochemical evidence for its link to AD by forwarding lipids to ApoE.

How the gut microbiota impacts neurodegenerative diseases by modulating CNS immune cells

Alzheimer's disease (AD) is the most common neurodegenerative disease worldwide. Amyloid-β (Aβ) accumulation and neurofibrillary tangles are two key histological features resulting in progressive and irreversible neuronal loss and cognitive decline. The macrophages of the central nervous system (CNS) belong to the innate immune system and comprise parenchymal microglia and CNS-associated macrophages (CAMs) at the CNS interfaces (leptomeninges, perivascular space and choroid plexus). Microglia and CAMs have received attention as they may play a key role in disease onset and progression e. g., by clearing amyloid beta (Aβ) through phagocytosis. Genome-wide association studies (GWAS) have revealed that human microglia and CAMs express numerous risk genes for AD, further highlighting their potentially critical role in AD pathogenesis. Microglia and CAMs are tightly controlled by environmental factors, such as the host microbiota. Notably, it was further reported that the composition of the gut microbiota differed between AD patients and healthy individuals. Hence, emerging studies have analyzed the impact of gut bacteria in different preclinical mouse models for AD as well as in clinical studies, potentially enabling promising new therapeutic options.

ABTrans: A Transformer-based Model for Predicting Interaction between Anti-Aβ Antibodies and Peptides

Antibodies against Aβ peptide have been recently approved to treat Alzheimer's disease, underscoring the importance of understanding their interactions for developing more potent treatments. Here we investigated the interaction between anti-Aβ antibodies and various peptides using a deep learning model. Our model, ABTrans, was trained on dodecapeptide sequences from phage display experiments and known anti-Aβ antibody sequences sourced from public sources. It classified the binding ability between anti-Aβ antibodies and dodecapeptides into four levels: not binding, weak binding, medium binding, and strong binding, achieving an accuracy of 0.83. Using ABTrans, we examined the cross-reaction of anti-Aβ antibodies with other human amyloidogenic proteins, revealing that Aducanumab and Donanemab exhibited the least cross-reactivity. Additionally, we systematically screened interactions between eleven selected anti-Aβ antibodies and all human proteins to identify potential off-target candidates.

Specific Targeting and Imaging of RNA G-Quadruplex (rG4) Structure Using Non-G4-Containing l-RNA Aptamer and Fluorogenic l-Aptamer

RNA G-quadruplex structures (rG4s) play important roles in the regulation of biological processes. So far, all the l-RNA aptamers developed to target rG4 of interest contain G4 motif itself, raising the question of whether non-G4-containing l-RNA aptamer can be developed to target rG4. Furthermore, it is unclear whether an l-Aptamer-based tool can be generated for G4 detection in vitro and imaging in cells. Herein, a new strategy is designed using a low GC content template library to develop a novel non-G4-containing l-RNA aptamer with strong binding affinity and improved binding specificity to rG4 of interest. The first non-G4-containing l-Aptamer, l-Apt.1-1, is identified with nanomolar binding affinity to amyloid precursor protein (APP) D-rG4. l-Apt.1-1 is applied to control APP gene expression in cells via targeting APP D-rG4 structure. Moreover, the first l-RNA-based fluorogenic bi-functional aptamer (FLAP) system is developed, and l-Apt.1-1_Pepper is engineered for in vitro detection and cellular imaging of APP D-rG4. This work provides an original approach for developing non-G4-containing l-RNA aptamer for rG4 targeting, and the novel l-Apt.1-1 developed for APP gene regulation, as well as the l-Apt.1-1_Pepper generated for imaging of APP rG4 structure can be further used in other applications in vitro and in cells.

DNLA Delayed the Appearance of Learning and Memory Impairment of APP/PS1 Mice: Involvement of mTOR/TFEB/v-ATPase Signaling Pathway

INTRODUCTION

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with cognitive impairment that currently is incurable. There is existing evidence to suggest that vacuolar adenosine triphosphatase (v-ATPase) is one of the early key driving factors in the pathological process of AD. Thus, early intervention of v-ATPase may be a viable strategy.

AIMS

Observing whether early intervention with DNLA can delay learning and memory impairment in mice, and further exploring the mechanism of DNLA delaying AD in vitro based on v-ATPase.

METHODS

Four-month-old APP/PS1 transgenic mice were treated with alkaloids from Dendrobium nobile Lindl (DNLA) 20 and 40 mg/kg/day for 5 months. The Morris water maze test and nest test showed that DNLA administration significantly delayed the appearance of cognitive deficits in APP/PS1 mice. We further investigated the mechanism of DNLA promoting lysosome acidification in vitro by using PC12 cells.

RESULTS

We found that DNLA increases the degradation of β-amyloid (Aβ) contained in the autophagic lysosomes and alleviates the aging of neurons by promoting lysosome acidification and improving autophagy flow. In PC12 cells, DDB could promote the separation of mTOR and lysosome, promote the nuclear translocation of transcription factor EB (TFEB), and then promote lysosome biogenesis and lysosome acidification by targeting ATP6V1A.

CONCLUSION

These results unraveled that preventive administration of DNLA may delay the impairment of learning and memory in APP/PS1 mice. The molecular mechanism may be related to promoting the mTOR-TFEB-v-ATPase pathway.

The role of ferritinophagy and ferroptosis in Alzheimer's disease

Iron is a crucial mineral element within human cells, serving as a pivotal cofactor for diverse biological enzymes. Ferritin plays a crucial role in maintaining iron homeostasis within the body through its ability to sequester and release iron. Ferritinophagy is a selective autophagic process in cells that specifically facilitates the degradation of ferritin and subsequent release of free iron, thereby regulating intracellular iron homeostasis. The nuclear receptor coactivator 4 (NCOA4) serves as a pivotal regulator in the entire process of ferritinophagy, facilitating its binding to ferritin and subsequent delivering to lysosomes for degradation, thereby enabling the release of free iron. The free iron ions within the cell undergo catalysis through the Fenton reaction, resulting in a substantial generation of reactive oxygen species (ROS). This process induces lipid peroxidation, thereby stimulating a cascade leading to cellular tissue damage and subsequent initiation of ferroptosis. Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive deterioration of emotional memory and cognitive function, accompanied by mental and behavioral aberrations. The pathology of the disease is characterized by aberrant deposition of amyloid β-protein (Aβ) and hyperphosphorylated tau protein. It has been observed that evident iron metabolism disorders and accumulation of lipid peroxides occur in AD, indicating a significant impact of ferritinophagy and ferroptosis on the pathogenesis and progression of AD. This article elucidates the process and mechanism of ferritinophagy and ferroptosis, investigating their implications in AD to identify novel targets for therapeutic intervention.

Daily fluid intake and brain amyloid deposition: A cohort study

BackgroundLittle information is yet available for the association between daily water intake, a modifiable lifestyle factor, and Alzheimer's disease (AD) pathology and cerebrovascular injury in the living human brain.ObjectiveOur aim was to explore the correlation between daily fluid intake and in vivo AD pathologies (i.e., amyloid-β (Aβ) and tau) and cerebrovascular injury.Methods287 cognitively normal (CN) older adults completed extensive clinical assessments, daily fluid intake evaluations, and multimodal brain imaging at both the initial baseline and the subsequent 2-year follow-up.ResultsLow daily fluid intake was significantly associated with a higher level or a more rapid increase of Aβ deposition, especially in apolipoprotein E4 negative individuals. Meanwhile, low daily fluid intake was cross-sectionally related with cerebrovascular injury.ConclusionsOur findings suggest that high daily fluid intake is associated with decreased brain amyloid deposition, indicating that sufficient daily fluid intake may be helpful for prevention of AD.

CRISPR-based epigenetic editing of Gad1 improves synaptic inhibition and cognitive behavior in a Tauopathy mouse model

GABAergic signaling in the brain plays a key role in regulating synaptic transmission, neuronal excitability, and cognitive processes. Large-scale sequencing has revealed the diminished expression of GABA-related genes in Alzheimer's disease (AD), however, it is largely unclear about the epigenetic mechanisms that dysregulate the transcription of these genes in AD. We confirmed that GABA synthesizing enzymes, GAD1 and GAD2, were significantly downregulated in prefrontal cortex (PFC) of AD human postmortem tissues. A tauopathy mouse model also had the significantly reduced expression of GABA-related genes, as well as the diminished GABAergic synaptic transmission in PFC pyramidal neurons. To elevate endogenous Gad1 levels, we used the CRISPR/Cas9-based epigenome editing technology to recruit histone acetyltransferase p300 to Gad1. Cells transfected with a fusion protein consisting of the nuclease-null dCas9 protein and the catalytic core of p300 (dCas9p300), as well as a guide RNA targeting Gad1 promoter (gRNAGad1), had significantly increased Gad1 mRNA expression and histone acetylation at Gad1 promoter. Furthermore, the tauopathy mouse model with PFC injection of dCas9p300 and gRNAGad1 lentiviruses had significantly elevated GABAergic synaptic currents and improved spatial memory. These results have provided an epigenetic editing-based gene-targeting strategy to restore synaptic inhibition and cognitive function in AD and related disorders.

Advanced nano delivery system for stem cell therapy for Alzheimer's disease

Alzheimer's Disease (AD) represents one of the most significant neurodegenerative challenges of our time, with its increasing prevalence and the lack of curative treatments underscoring an urgent need for innovative therapeutic strategies. Stem cells (SCs) therapy emerges as a promising frontier, offering potential mechanisms for neuroregeneration, neuroprotection, and disease modification in AD. This article provides a comprehensive overview of the current landscape and future directions of stem cell therapy in AD treatment, addressing key aspects such as stem cell migration, differentiation, paracrine effects, and mitochondrial translocation. Despite the promising therapeutic mechanisms of SCs, translating these findings into clinical applications faces substantial hurdles, including production scalability, quality control, ethical concerns, immunogenicity, and regulatory challenges. Furthermore, we delve into emerging trends in stem cell modification and application, highlighting the roles of genetic engineering, biomaterials, and advanced delivery systems. Potential solutions to overcome translational barriers are discussed, emphasizing the importance of interdisciplinary collaboration, regulatory harmonization, and adaptive clinical trial designs. The article concludes with reflections on the future of stem cell therapy in AD, balancing optimism with a pragmatic recognition of the challenges ahead. As we navigate these complexities, the ultimate goal remains to translate stem cell research into safe, effective, and accessible treatments for AD, heralding a new era in the fight against this devastating disease.

Locus coeruleus vulnerability to tau hyperphosphorylation in a rat model

Post-mortem investigations indicate that the locus coeruleus (LC) is the initial site of hyperphosphorylated pretangle tau, a precursor to neurofibrillary tangles (NFTs) found in Alzheimer's disease (AD). The presence of pretangle tau and NFTs correlates with AD progression and symptomatology. LC neuron integrity and quantity are linked to cognitive performance, with degeneration strongly associated with AD. Despite their importance, the mechanisms of pretangle tau-induced LC degeneration are unclear. This study examined the transcriptomic and mitochondrial profiles of LC noradrenergic neurons after transduction with pseudophosphorylated human tau. Tau hyperphosphorylation increased the somatic expression of the L-type calcium channel (LTCC), impaired mitochondrial health, and led to deficits in spatial and olfactory learning. Sex-dependent alterations in gene expression were observed in rats transduced with pretangle tau. Chronic LTCC blockade prevented behavioral deficits and altered mitochondrial mRNA expression, suggesting a potential link between LTCC hyperactivity and mitochondrial dysfunction. Our research provides insights into the consequences of tau pathology in the originating structure of AD.

Aerobic exercise improves clearance of amyloid-β via the glymphatic system in a mouse model of Alzheimer's Disease

BACKGROUND

Aerobic exercise training can promote the recovery of learning and memory ability in Alzheimer's disease (AD), but the specific mechanism is still unclear. Previous studies have suggested that aquaporin-4 (AQP4)-mediated glymphatic system is an important way to clear β-amyloid (Aβ) in the brain, which is closely related to learning and memory impairment in AD. However, it remains unclear whether AQP4 regulates glymphatic clearance of Aβ which contributes to the beneficial effects of aerobic exercise in AD patients. Here, the goal of this study was to investigate the mechanisms about aerobic exercise whether AQP4 could modulate glymphatic system using APP/PS1 mice.

METHODS

In this study, APP/PS1 AD model mice were treated with aerobic exercise intervention through swimming exercise training for 4 weeks, and the two groups of mice were injected with AQP4 inhibition virus and empty virus, respectively. Their learning and memory abilities were assessed using behavioral tests, such as the Barnes maze and Morris water maze tests. Hippocampus was obtained from sacrificed mice and used for histological analysis. Tracer imaging of the cerebellar medullary pool was used to observed the CSF-ISF exchange, immunohistochemistry was used to detect the level of Aβ plaques in the hippocampus of mice in each group; immunoblotting was used to detect the expression of AQP4 protein; immunofluorescence co-labeling was used to detect the polarization distribution of AQP4; qRT-PCR was used to detect the transcription levels of AQP4 and its anchoring proteins.

RESULTS

The funding showed that APP/PS1 mice have learning and memory impairment, and the glymphatic system is dysfunction. Swimming training can improve the ability of the glymphatic system to clear Aβ deposition in the hippocampus by up-regulating the transcription levels of Lama1 and Dp71 in the hippocampus, reducing the depolarization distribution of AQP4 in the hippocampus, and enhancing the exchange of CSF-ISF. Thus, improves learning and memory impairment in APP/PS1 mice.

CONCLUSIONS

Swimming training can rescue the function of the glymphatic system, increase the CSF-ISF exchange, promote the polarization distribution of AQP4, and reduce the deposition of Aβ in the hippocampus, thereby improving the learning and memory ability of APP/PS1 mice.

Gut Microbiota Mediates Neuroinflammation in Alzheimer's Disease: Unraveling Key Factors and Mechanistic Insights

The gut microbiota, the complex community of microorganisms that inhabit the gastrointestinal tract, has emerged as a key player in the pathogenesis of neurodegenerative disorders, including Alzheimer's disease (AD). AD is characterized by progressive cognitive decline and neuronal loss, associated with the accumulation of amyloid-β plaques, neurofibrillary tangles, and neuroinflammation in the brain. Increasing evidence suggests that alterations in the composition and function of the gut microbiota, known as dysbiosis, may contribute to the development and progression of AD by modulating neuroinflammation, a chronic and maladaptive immune response in the central nervous system. This review aims to comprehensively analyze the current role of the gut microbiota in regulating neuroinflammation and glial cell function in AD. Its objective is to deepen our understanding of the pathogenesis of AD and to discuss the potential advantages and challenges of using gut microbiota modulation as a novel approach for the diagnosis, treatment, and prevention of AD.

Delayed primacy recall in AVLT is associated with medial temporal tau PET burden in cognitively unimpaired adults

BACKGROUND

Alzheimer's disease (AD) can be diagnosed by in vivo abnormalities of amyloid-β plaques (A) and tau accumulation (T) biomarkers. Previous studies have shown that analyses of serial position performance in episodic memory tests, and especially, delayed primacy, are associated with AD pathology even in individuals who are cognitively unimpaired. The earliest signs of cortical tau pathology are observed in medial temporal lobe (MTL) regions, yet it is unknown if serial position markers are also associated with early tau load in these regions. This study of cognitively unimpaired older individuals examined whether serial position scores in word-list recall cross-sectionally predicted tau PET load in the MTL, and were able to discriminate between biomarker profiles, based on AT classification.

METHODS

Data from 490 participants (mean age = 68.8 ± 7.2) were extracted from two cohorts, which were merged into one sample. Linear regression analyses were carried out with regional volume-controlled tau (18F-MK-6240) PET SUVR of the entorhinal cortex (EC), parahippocampal cortex (PHC) and hippocampus (H) as outcomes, cross-sectional memory scores from the Rey Auditory Verbal Learning Test as predictors (total and delayed recall, along with serial position scores) and control variables, in separate analyses for each outcome and predictor. The sample was then stratified by biomarker profile and ANCOVAs were conducted with the strongest scores from the regression analyses, AT groups as fixed factor and the covariates.

RESULTS

Higher delayed primacy significantly predicted lower tau PET in EC, PHC, and H, cross-sectionally. Higher total recall scores predicted lower EC tau, but delayed primacy showed the best model fit, as indicated by AICs. ANCOVAs showed that AVLT metrics did not significantly discriminate between A-T- and A+T+, after correcting for multiple comparisons.

CONCLUSIONS

Serial position analysis of word-list recall, particularly delayed primacy, may be a valuable tool for identifying in vivo tau pathology in cognitively unimpaired individuals.

Driving research on successful aging and neuroprotection in Latin America: Insights from the inaugural symposium on brain resilience and healthy longevity

INTRODUCTION

Global life expectancy has steadily increased in recent decades, resulting in a significant rise in the number of individuals aged 80 years and older. This trend is also evident in Latin America, where life expectancy is improving, though at varying rates across countries and regions.

METHODS

Partnering with the Neurosciences Group of Antioquia (GNA), we launched a Colombian study on resilience in families with autosomal dominant Alzheimer's disease and the oldest-old population. Over the past 2 years, the project has expanded to include participants from Peru, Chile, and Costa Rica.

RESULTS

This research led to the first symposium on Brain Resilience and Healthy Longevity, held in Medellín, Colombia, in August 2024.

DISCUSSION

The article summarizes key discussions from the symposium, highlighting the most promising opportunities for brain resilience and prevention research in the region and offering recommendations for future research to promote healthy aging and dementia-free communities.

HIGHLIGHTS

Uncovering the genetic and physiological drivers of cognitive resilience, neurodegeneration resistance, and healthy longevity is essential for maintaining brain function as we age. "Superagers" and cognitively resilient individuals from Latin American families with Alzheimer's disease offer valuable insights into brain protection mechanisms. Studying the interplay of socio-environmental and genetic factors in the oldest-old is key to understanding healthy longevity and improving dementia prevention. The inaugural Brain Resilience and Healthy Longevity Symposium highlights the need for global collaboration to uncover factors that drive cognitive resilience and healthy aging in Latin America, advancing dementia prevention.

Exercise-Induced Reduction of IGF1R Sumoylation Attenuates Neuroinflammation in APP/PS1 Transgenic Mice

INTRODUCTION

Alzheimer's Disease (AD), a progressive neurodegenerative disorder, is marked by cognitive deterioration and heightened neuroinflammation. The influence of Insulin-like Growth Factor 1 Receptor (IGF1R) and its post-translational modifications, especially sumoylation, is crucial in understanding the progression of AD and exploring novel therapeutic avenues.

OBJECTIVES

This study investigates the impact of exercise on the sumoylation of IGF1R and its role in ameliorating AD symptoms in APP/PS1 mice, with a specific focus on neuroinflammation and innovative therapeutic strategies.

METHODS

APP/PS1 mice were subjected to a regimen of moderate-intensity exercise. The investigation encompassed assessments of cognitive functions, alterations in hippocampal protein expressions, neuroinflammatory markers, and the effects of exercise on IGF1R and SUMO1 nuclear translocation. Additionally, the study evaluated the efficacy of KPT-330, a nuclear export inhibitor, as an alternative to exercise.

RESULTS

Exercise notably enhanced cognitive functions in AD mice, possibly through modulations in hippocampal proteins, including Bcl-2 and BACE1. A decrease in neuroinflammatory markers such as IL-1β, IL-6, and TNF-α was observed, indicative of reduced neuroinflammation. Exercise modulated the nuclear translocation of SUMO1 and IGF1R in the hippocampus, thereby facilitating neuronal regeneration. Mutant IGF1R (MT IGF1R), lacking SUMO1 modification sites, showed reduced SUMOylation, leading to diminished expression of pro-inflammatory cytokines and apoptosis. KPT-330 impeded the formation of the IGF1R/RanBP2/SUMO1 complex, thereby limiting IGF1R nuclear translocation, inflammation, and neuronal apoptosis, while enhancing cognitive functions and neuron proliferation.

CONCLUSION

Moderate-intensity exercise effectively mitigates AD symptoms in mice, primarily by diminishing neuroinflammation, through the reduction of IGF1R Sumoylation. KPT-330, as a potential alternative to physical exercise, enhances the neuroprotective role of IGF1R by inhibiting SUMOylation through targeting XPO1, presenting a promising therapeutic strategy for AD.

Gut microbiota dysbiosis in Alzheimer's disease (AD): Insights from human clinical studies and the mouse AD models

Alzheimer's Disease (AD) is a debilitating neurocognitive disorder with an unclear underlying mechanism. Recent studies have implicated gut microbiota dysbiosis with the onset and progression of AD. The connection between gut microbiota and AD can significantly affect the prevention and treatment of AD patients. This systematic review summarizes primary outcomes of human and mouse AD models concerning gut microbiota alterations. A systematic literature search in February through March 2023 was conducted on PubMed, Embase, and Web of Science. We identified 711 as potential manuscripts of which 672 were excluded because of irrelevance to the identified search criteria. Primary outcomes include microbiota compositions of control and AD models in humans and mice. In total, 39 studies were included (19 mouse and 20 human studies), published between 2017 and 2023. We included studies involving well-established mice models of AD (5xFAD, 3xTg-AD, APP/PS1, Tg2576, and APPPS2) which harbor mutations and genes that drive the formation of Aß plaques. All human studies were included on those with AD or mild cognitive impairment. Among alterations in gut microbiota, most studies found a decreased abundance of the phyla Firmicutes and Bifidobacteria, a genus of the phylum Actinomycetota. An increased abundance of the phyla Bacteroidetes and Proteobacteria were identified in animal and human studies. Studies indicated that gut microbiota alter the pathogenesis of AD through its impact on neuroinflammation and permeability of the gastrointestinal tract. The ensuing increase in blood-brain barrier permeability may accelerate Aβ penetrance and formation of neuritic plaques that align with the amyloid hypothesis of AD pathogenesis. Further studies should assess the relationship between gut microbiota and AD progression and therapy preserving beneficial gut microbiota.

An Update of Salivary Biomarkers for the Diagnosis of Alzheimer's Disease

Alzheimer's disease (AD) is characterized by progressive cognition and behavior impairments. Diagnosing AD early is important for clinicians to slow down AD progression and preserve brain function. Biomarkers such as tau protein and amyloid-β peptide (Aβ) are used to aid diagnosis as clinical diagnosis often lags. Additionally, biomarkers can be used to monitor AD status and evaluate AD treatment. Clinicians detect these AD biomarkers in the brain using positron emission tomography/computed tomography or in the cerebrospinal fluid using a lumbar puncture. However, these methods are expensive and invasive. In contrast, saliva collection is simple, inexpensive, non-invasive, stress-free, and repeatable. Moreover, damage to the brain parenchyma can impact the oral cavity and some pathogenic molecules could travel back and forth from the brain to the mouth. This has prompted researchers to explore biomarkers in the saliva. Therefore, this study provides an overview of the main finding of salivary biomarkers for AD diagnosis. Based on these available studies, Aβ, tau, cholinesterase enzyme activity, lactoferrin, melatonin, cortisol, proteomics, metabolomics, exosomes, and the microbiome were changed in AD patients' saliva when compared to controls. However, well-designed studies are essential to confirm the reliability and validity of these biomarkers in diagnosing and monitoring AD.

Rhynchophylline alleviates cognitive deficits in multiple transgenic mouse models of Alzheimer's disease via modulating neuropathology and gut microbiota

Amyloid-beta (Aβ) aggregation, phosphorylated tau accumulation and neuroinflammation are considered as three hallmarks of Alzheimer's disease (AD). Rhynchophylline (RN), the major alkaloid of a Chinese medicinal plant Uncaria rhynchophylla, has been shown to possess potent anti-AD effects. This study explored the effects of RN on Aβ pathology, tauopathy, and neuroinflammation using three AD mouse models, including TgCRND8, 3×Tg-AD, and 5×FAD, with RN treatment lasting for 4, 6, and 6 months, respectively, followed by behavioral tests and biological assays. In addition, BV2 cells were employed to further evaluate the biological effects of RN. RN treatment improved cognitive functions by reducing anxiety-like behaviors, enhancing recognition ability, and ameliorating learning impairments. It modulated Aβ processing through reducing the Aβ-producing enzyme activities and enhancing degradation enzyme activities, thereby diminishing Aβ accumulation. RN also decreased hyperphosphorylated tau proteins at Thr181, Thr205, Ser396, and Ser404 sites. Moreover, RN diminished neuroinflammation by reducing microglia and astrocyte activation and lowering the release of inflammatory cytokines. Furthermore, RN treatment could restore gut microbiota dysbiosis in 5×FAD mice. In BV2 cells, knockdown of p53, HDAC2, and Galectin-3 markedly enhanced the anti-inflammatory effects of RN. Overall, the anti-AD properties of RN were attributed to its regulation of multiple biological pathways, including regulation of the p53/PINK1 signaling pathway, inhibition of the HDAC2/AMPK signaling pathway, suppression of the Galectin-3/C/EBPβ/AEP signaling pathway, and modulation of gut microflora dysbiosis. This pioneering study unambiguously revealed the effects of RN on cognitive impairments, APP processing, tauopathy, and neuroinflammation in different transgenic mouse models with differing AD burdens, highlighting its potential as an anti-AD therapeutic agent and enhancing the scientific basis for its clinical use in treating AD.

Real-World Insights Into Dementia Diagnosis Trajectory and Clinical Practice Patterns Unveiled by Natural Language Processing: Development and Usability Study

Background

Understanding the dementia disease trajectory and clinical practice patterns in outpatient settings is vital for effective management. Knowledge about the path from initial memory loss complaints to dementia diagnosis remains limited.

Objective

This study aims to (1) determine the time intervals between initial memory loss complaints and dementia diagnosis in outpatient care, (2) assess the proportion of patients receiving cognition-enhancing medication prior to dementia diagnosis, and (3) identify patient and provider characteristics that influence the time between memory complaints and diagnosis and the prescription of cognition-enhancing medication.

Methods

This retrospective cohort study used a large outpatient electronic health record (EHR) database from the University of Connecticut Health Center, covering 2010-2018, with a cohort of 581 outpatients. We used a customized deep learning-based natural language processing (NLP) pipeline to extract clinical information from EHR data, focusing on cognition-related symptoms, primary caregiver relation, and medication usage. We applied descriptive statistics, linear, and logistic regression for analysis.

Results

The NLP pipeline showed precision, recall, and F1-scores of 0.97, 0.93, and 0.95, respectively. The median time from the first memory loss complaint to dementia diagnosis was 342 (IQR 200-675) days. Factors such as the location of initial complaints and diagnosis and primary caregiver relationships significantly affected this interval. Around 25.1% (146/581) of patients were prescribed cognition-enhancing medication before diagnosis, with the number of complaints influencing medication usage.

Conclusions

Our NLP-guided analysis provided insights into the clinical pathways from memory complaints to dementia diagnosis and medication practices, which can enhance patient care and decision-making in outpatient settings.

25-Hydroxycholesterol modulates microglial function and exacerbates Alzheimer's disease pathology: mechanistic insights and therapeutic potential of cholesterol esterification inhibition

This study investigates the role of 25-hydroxycholesterol (25HC), a metabolite produced by cholesterol hydroxylase encoded by the Ch25h gene, in modulating microglial function and its potential implications in Alzheimer's disease (AD) pathology. We demonstrated that 25HC impairs microglial surveillance, reduces phagocytic capacity, and increases the production of pro-inflammatory cytokines. In vivo two-photon microscopy revealed that 25HC administration diminishes microglial response to brain lesions, while flow cytometry confirmed reduced phagocytosis in both in vivo and in vitro models. Additionally, amyloid-beta (Aβ) was shown to upregulate Ch25h expression and elevate 25HC levels in microglia, exacerbating these functional impairments. Mechanistically, 25HC was found to enhance cholesterol esterification, disrupt cell membrane dynamics, and further reduce microglial mobility and phagocytosis. Treatment with Avasimibe, a cholesterol esterification inhibitor, restored membrane dynamics and microglial function, leading to attenuated AD pathology in a 5XFAD mouse model. These findings suggest that 25HC-induced changes in microglial function contribute to AD progression, and targeting cholesterol metabolism could offer therapeutic potential.

Amyloid-β oligomers drive amyloid deposit and cascaded tau pathology of Alzheimer's disease in aged brains of non-human primates

Alzheimer's disease (AD), the most prevalent form of dementia, disproportionately affects the elderly population. While aging is widely recognized as a major risk factor for AD, the precise mechanisms by which aging contributes to the pathogenesis of AD remain poorly understood. In our previous work, the neuropathological changes in the brains of aged cynomolgus monkeys (≥18 years old) following parenchymal cerebral injection of amyloid-β oligomers (AβOs) have been characterized. Here, we extend our investigation to middle-aged cynomolgus monkeys (≤15 years old) to establish an AD model. Surprisingly, immunohistochemical analysis reveals no detectable AD-related pathology in the brains of middle-aged monkeys, even after AβOs injection. In a comprehensive pathological analysis of 38 monkeys, we observe that the amyloid-β (Aβ) burden increases significantly with advancing age. Notably, the density of Aβ plaques is markedly higher in the ventral regions compared to the dorsal regions of aged monkey brains. Furthermore, we demonstrate that tau phosphorylation coincides with the accumulation of extensive Aβ plaques and exhibits a positive correlation with Aβ burden in aged monkeys. Collectively, these findings underscore the critical role of the aged brain in providing the necessary conditions for AβO-induced AD pathologies in cynomolgus monkeys.

Inhibition of Soluble Epoxide Hydrolase Confers Neuroprotection and Restores Microglial Homeostasis in a Tauopathy Mouse Model

Background

The epoxyeicosatrienoic acids (EETs) are derivatives of the arachidonic acid metabolism with anti-inflammatory activities. However, their efficacy is limited due to the rapid hydrolasis by the soluble epoxide hydrolase (sEH). Accordingly, inhibition of sEH has been shown to stabilize the EETs and dampen neuroinflammation in Aβ mouse models of Alzheimer's disease (AD). However, the role of the sEH-EET signaling pathway in other cell types of the CNS and in other neurodegenerative conditions are less understood.

Methods

Here we examined the mechanisms and the functional role of the sEH-EET axis in tauopathy by treating the PS19 mice with a small molecule sEH inhibitor TPPU and by crossing the PS19 mice with Ephx2 (gene encoding sEH) knockout mice, followed by single-nucleus RNA-sequencing (snRNA-seq), biochemical and immunohistochemical characterization, and behavioral analysis. We also tested the effect of the sEH-EET pathway in primary microglia cultures and human induced pluripotent stem cell (iPSC)-derived neurons that develop seeding-induced Tau inclusions.

Results

We show that sEH inhibition improved cognitive function, rescued neuronal cell loss, and reduced Tau pathology and microglia reactivity. snRNA-seq revealed that TPPU treatment resulted in the upregulation of actin cytoskeleton and excitatory synaptic pathway genes. Treating the human iPSC-derived neurons with TPPU led to enhanced synaptic density without affecting Tau accumulation, indicating a cell-autonomous effect of sEH blockade in neuroprotection. Further, sEH inhibition reversed disease-associated and interferon-response microglia states in PS19 mice and EET supplementation enhanced Tau phagocytosis and clearance in primary microglia cultures.

Conclusion

These findings demonstrate that sEH blockade or EET augmentation confer therapeutic benefit against neurodegenerative tauopathies through parallel targeting of neuronal and microglial pathways.

Identification of UBE2N as a biomarker of Alzheimer's disease by combining WGCNA with machine learning algorithms

Alzheimer's disease (AD) is the most common cause of dementia, emphasizing the critical need for the development of biomarkers that facilitate accurate and objective assessment of disease progression for early detection and intervention to delay its onset. In our study, three AD datasets from the Gene Expression Omnibus (GEO) database were integrated for differential expression analysis, followed by a weighted gene co-expression network analysis (WGCNA), and potential AD biomarkers were screened. Our study identified UBE2N as a promising biomarker for AD. Functional enrichment analysis revealed that UBE2N is associated with synaptic vesicle cycling and T cell/B cell receptor signaling pathways. Notably, UBE2N expression levels were found to be significantly reduced in the cortex and hippocampus of the TauP301S mice. Furthermore, analysis of single-cell data from AD patients demonstrated the association of UBE2N and T cell function. These findings underscore the potential of UBE2N as a valuable biomarker for AD, offering important insights for diagnosis and targeted therapeutic strategies.

Clinical Aspects of Mental Imagery in Alzheimer's Disease-Related Dementia: A Review of Cognitive, Motor, and Emotional Interventions

The present review describes the use and effectiveness of mental imagery in Alzheimer's disease-related dementia. Six databases were thoroughly searched from January 2010 to December 2024. Different types of studies were retrieved and reviewed for imagery of the motor, cognitive, and emotional states and quality of life of the elderly with dementia. Although the scarce results showed the positive effect of mental imagery to the every-day life of older adults with dementia, more research should be conducted with larger homogenous samples and more valid tools. Future recommendations are provided.

Gut microbiota: A new window for the prevention and treatment of neuropsychiatric disease

Under normal physiological conditions, gut microbiota and host mutually coexist. They play key roles in maintaining intestinal barrier integrity, absorption, and metabolism, as well as promoting the development of the central nervous system (CNS) and emotional regulation. The dysregulation of gut microbiota homeostasis has attracted significant research interest, specifically in its impact on neurological and psychiatric disorders. Recent studies have highlighted the important role of the gut- brain axis in conditions including Alzheimer's Disease (AD), Parkinson's Disease (PD), and depression. This review aims to elucidate the regulatory mechanisms by which gut microbiota affect the progression of CNS disorders via the gut-brain axis. Additionally, we discuss the current research landscape, identify gaps, and propose future directions for microbial interventions against these diseases. Finally, we provide a theoretical reference for clinical treatment strategies and drug development for AD, PD, and depression.

Could Blood Transfusion Increase the Risk of Alzheimer's Disease? A Narrative Review

Alzheimer's disease (AD) is the most common progressive neurodegenerative disease, and its pathogenesis is complex. In addition to amyloid-β and phosphorylated tau, inflammation and microbial infections also play a role in the development of AD. Currently, there is no effective clinical intervention to cure AD or completely halt its progression. Blood transfusion, a critical life-saving medical procedure widely employed in modern healthcare, faces growing demand due to global population aging. However, whether blood transfusion could increase the risk of AD is still not clear. Aβ and tau play major roles in the pathogenesis of AD and may possess the potential for transmission through blood transfusion. Iron overload and chronic inflammation, which can independently influence AD pathogenesis, may result from repeated transfusions. Additionally, herpesvirus, known to accelerate AD progression, can also be potentially transmitted by blood transfusion. In this study, recent advances in the associations between blood transfusion and the occurrence and development of AD were reviewed, and whether blood transfusion could increase the risk of AD was discussed. Furthermore, the related proposals for blood management and future research were advanced to provide references for the prevention and control of AD.

Understanding monocyte-driven neuroinflammation in Alzheimer's disease using human brain organoid microphysiological systems

Increasing evidence suggests that Alzheimer's disease (AD) pathogenesis strongly correlates with neuroinflammation. Peripheral monocytes are crucial components of the human immune system that may play a role in neuroinflammation, but their contribution to AD pathogenesis is largely understudied partially due to the lack of appropriate human models. Here, we present human cortical organoid microphysiological systems (hCO-MPSs) for modeling dynamic AD neuroinflammation mediated by monocytes. By incorporating 3D printed devices into an existing cortical organoid protocol, 96 hCO-MPSs can be established with significantly reduced necrosis and hypoxia as well as enhanced viability within a commonly used 96 well plate, and each hCO-MPS consists of a doughnut-shaped hCO and a 3D printed device per well. Using this approach, monocytes from AD patients exhibit higher infiltration, decreased amyloid-beta (Aβ) clearance, and stronger inflammatory responses compared to monocytes from age-matched control donors. Moreover, pro-inflammatory effects such as elevated astrocyte activation and neuronal apoptosis were observed to be induced by AD monocytes. Furthermore, the significant increase in the expression of IL1B and CCL3, both at the transcriptional and protein levels, indicated the pivotal role of these cytokine and chemokine in monocyte-mediated AD neuroinflammation. Our findings provide insight for understanding monocytes' role in AD pathogenesis, and the user-friendly MPS models we present are compatible with existing laboratory settings, highlighting their potential for modeling neuroinflammation and developing new therapeutics for various neuroinflammatory diseases.

Cholinesterase Inhibitors from Plants and Their Potential in Alzheimer's Treatment: Systematic Review

INTRODUCTION

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by memory loss and cognitive decline, primarily due to dysfunction of acetylcholine caused by acetylcholinesterase and butyrylcholinesterase. While synthetic cholinesterase inhibitors like donepezil, rivastigmine, and galantamine are commonly used, they have notable side effects, prompting interest in natural alternatives. Medicinal plants, rich in bioactive compounds like flavonoids and alkaloids, have shown potential as cholinesterase inhibitors with additional antioxidants and anti-inflammatory benefits. This study aimed to evaluate the cholinesterase-inhibiting effects of various plant species and their compounds to identify new therapeutic candidates and reduce side effects.

METHOD

A PRISMA-compliant review was conducted, screening studies from multiple databases, with a final inclusion of 64 in vivo studies.

RESULTS

These studies highlighted plant extracts such as Ferula ammoniacum, Elaeagnus umbellata, Bacopa monnieri, and Centella asiatica, which improved memory, reduced oxidative stress, and provided neuroprotection. Some extracts also reduced amyloid plaques, enhanced neuronal integrity, and restored cholinesterase activity, indicating their potential as therapeutic agents for AD and other neurodegenerative diseases.

CONCLUSIONS

The findings underscore the promise of plant-based compounds in treating cognitive decline and cholinergic dysfunction in AD, advocating for further research into their therapeutic potential.

Adolescent binge alcohol exposure accelerates Alzheimer's disease-associated basal forebrain neuropathology through proinflammatory HMGB1 signaling

Human studies suggest that heavy alcohol use may be an etiological factor contributing to the development of Alzheimer's disease (AD) neuropathology. Both alcohol use disorder (AUD) and AD share common underlying neuropathology, including proinflammatory high-mobility group box 1 (HMGB1)-mediated neuroimmune signaling and basal forebrain cholinergic neuron degeneration. Adolescent onset of binge drinking represents a significant risk factor for later development of an AUD, and accumulating evidence suggests that adolescent initiation of heavy alcohol use induces HMGB1 signaling and causes degeneration of the basal forebrain cholinergic system that persists into adulthood. However, it is unknown whether adolescent binge drinking confers increased risk for later development of AD-associated neuropathology through persistent induction of proinflammatory HMGB1 neuroimmune signaling. To investigate this question, we first (Experiment 1) assessed AD-associated neuropathology in the post-mortem human basal forebrain of individuals with AUD and an adolescent age of drinking onset relative to age-matched moderate drinking controls (CONs). In Experiment 2, we treated non-transgenic and 5xFAD male and female mice, which overexpress both mutant human APP and PS1, with adolescent intermittent ethanol (AIE; 5.0 g/kg, i.g. 2-days on/2-days off; postnatal day [P]30 - P55), and assessed AD-associated neuropathology in the adult (P100) basal forebrain. In Experiment 3, 5xFAD female mice received AIE treatment followed by glycyrrhizic acid (150 mg/L), an HMGB1 inhibitor, in drinking water from P56 to P100, and basal forebrain tissue was collected on P100 for assessment of AD-associated neuropathology. In the post-mortem human AUD basal forebrain (Experiment 1), we report upregulation of Hmgb1 and the HMGB1 receptors Rage and Tlr4 as well as microglial activation and increased intraneuronal Aβ1-42 accumulation in association with reduced cholinergic neuron marker expression (ChAT). In the 5xFAD mouse model (Experiment 2), AIE accelerated AD-associated induction of Hmgb1 proinflammatory neuroimmune genes, microglial activation, and reductions of ChAT+ basal forebrain cholinergic neurons in the adult female, but not male, basal forebrain. In Experiment 3, post-AIE treatment with glycyrrhizic acid rescued the AIE-induced acceleration of AD-associated increases in proinflammatory HMGB1 neuroimmune signaling, microglial activation, and persistent reductions of basal forebrain cholinergic neurons in adult 5xFAD female mice. Together, these findings suggest that adolescent binge ethanol exposure may represent an underappreciated etiological factor contributing to onset of AD-associated neuropathology in adulthood through HMGB1- mediated neuroimmune signaling.

Association between plasma cytokine levels and multiple neuroimaging modalities in mild cognitive impairment

BACKGROUND

The relationship between peripheral cytokines and neuroimaging biomarkers for Alzheimer's disease (AD) is not yet well established.

OBJECTIVE

To determine the association of cytokine plasma levels with brain amyloid deposition, cortical glucose metabolism, hippocampal volume, and white matter lesions (WMLs) in older adults with mild cognitive impairment (MCI).

METHODS

We recruited 50 older individuals with amnestic MCI (25 men and 25 women; median age, 75 years) and performed plasma analysis, 11C-Pittsburgh compound-B positron-emission tomography (PiB-PET), 18F-fluorodeoxyglucose positron-emission tomography, and magnetic resonance imaging. Global PiB and fluorodeoxyglucose (FDG) uptake were assessed by the ratio of the voxel number-weighted average of the mean uptake in the frontal, temporoparietal, and posterior cingulate, in reference to the cerebellum. The Fazekas scale was used to evaluate WMLs. Plasma levels of 48 cytokines were simultaneously measured with bead-based multiplex assays.

RESULTS

The plasma levels of IL-2Ra, IL-3, IL-5, IL-7, IL-9, IL-16, IL-18, fibroblast growth factor (FGF-basic), granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage inflammatory protein-1α (MIP-1α), regulated on activation, normal T-cell expressed and secreted (RANTES), tumor necrosis factor-α (TNF-α), cutaneous T-cell attracting chemokine (CTACK), growth-regulated oncogene α (GROα), hepatocyte growth factor (HGF), interferon-α2 (IFN-α2), leukemia inhibitory factor (LIF), monocyte chemoattractant protein-3 (MCP-3), β-nerve growth factor (β-NGF), stem cell factor (SCF), stem cell growth factor-β (SCGF-β), and TNF-related apoptosis-inducing ligand (TRAIL) were significantly associated with global PiB uptake, whereas those of IL-7 and GROα were significantly associated with hippocampal volume after covariate adjustment and false discovery rate correction.

CONCLUSIONS

Plasma cytokines are associated with brain amyloid deposition rather than brain dysfunction or hippocampal atrophy. Moreover, cytokines may play important roles in early-stage AD pathophysiology.

Investigating the neuroprotective effects of Dracocephalum moldavica extract and its effect on metabolomic profile of rat model of sporadic Alzheimer's disease

Alzheimer's disease (AD) is a progressive condition marked by multiple underlying mechanisms. Therefore, the investigation of natural products that can target multiple pathways presents a potential gate for the understanding and management of AD. This study aimed to assess the neuroprotective effects of the hydroalcoholic extract of Dracocephalum moldavica (DM) on cognitive impairment, biomarker changes, and putative metabolic pathways in a rat model of AD induced by intracerebroventricular streptozotocin (ICV-STZ). The DM extract was standardized and quantified based on examining total phenolic, total flavonoid, rosmarinic acid, and quercetin contents using colorimetry and high-performance liquid chromatography (HPLC) methods. The antioxidant potential of the extract was evaluated by 2,2-Diphenyl-1-picrylhydrazyl and nitric oxide radical scavenging assays. Male Wistar rats were injected with STZ (3 mg/kg, single dose, bilateral ICV) to induce a sporadic AD (sAD) model. Following model induction, rats were orally administered with DM extract (100, 200, and 400 mg/kg/day) or donepezil (5 mg/kg/day) for 21 days. Cognitive function was assessed using the radial arm water maze behavioral test. The histopathological evaluations were conducted in the cortex and hippocampus regions. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) was used to assess metabolite changes in various brain regions. DM extract significantly attenuated cognitive dysfunction induced by ICV-STZ according to behavioral and histopathological investigations. Thirty-two discriminating metabolites related to the amino acid metabolism; the glutamate/gamma-aminobutyric acid/glutamine cycle; nucleotide metabolism; lipid metabolism (glycerophospholipids, sphingomyelins, ceramides, phosphatidylserines, and prostaglandins), and glucose metabolic pathways were identified in the brains of rats with sAD simultaneously for the first time in this model. Polyphenols in DM extract may contribute to the regulation of these pathways. After treatment with DM extract, 10 metabolites from the 32 identified ones were altered in the brain tissue of a rat model of sAD, most commonly at doses of 200 and 400 mg/kg. In conclusion, this study demonstrates the neuroprotective potential of DM by upregulation/downregulation of various pathophysiological biomarkers such as adenine, glycerophosphoglycerol, inosine, prostaglandins, and sphingomyelin induced by ICV-STZ in sAD. These findings are consistent with cognitive behavioral results and histopathological outcomes.

ALZ-801 prevents amyloid β-protein assembly and reduces cytotoxicity: A preclinical experimental study

Alzheimer's disease (AD) is the most prevalent age-related neurodegenerative disorder, mainly characterized by amyloid β (Aβ) accumulation in the brain. Numerous new agents are currently undergoing clinical trials as disease-modifying therapies (DMTs) targeting Aβ. ALZ-801 is a promising candidate DMT for AD, with a phase 3 trial of ALZ-801 ongoing specifically for apolipoprotein E (APOE) ε4 homozygous patients with early-stage AD. This study aimed to examine the effects of ALZ-801 on Aβ assembly and explore its toxicological profile. Thioflavin T (ThT) assays and two imaging modalities-transmission electron microscopy (TEM) and high-speed atomic force microscopy (HS-AFM)-were used to evaluate ALZ-801's effects on Aβ assembly. To assess the effect of ALZ-801 on Aβ42-induced cytotoxicity, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays and lactate dehydrogenase (LDH) assays were performed. ThT assays revealed increased lag time and decreased fluorescence in the presence of ALZ-801, confirming inhibition of Aβ42 fibril formation, as confirmed by TEM. Real-time observation using HS-AFM revealed that ALZ-801 inhibited the formation of Aβ42 fibril from low-molecular-weight (LMW)-Aβ42 in the presence of Aβ42 seeds. HS-AFM also revealed that globular aggregates from LMW-Aβ42 were significantly larger with ALZ-801, with few fibrils noted. MTT and LDH assays indicated that ALZ-801 prevented LMW-Aβ42-induced cytotoxicity but did not reduce cytotoxicity induced by high-molecular-weight-Aβ42. ALZ-801 can inhibit Aβ42 aggregation by preventing both nucleus formation and fibril elongation, while promoting large globular oligomer formation, and can significantly reduce LMW-Aβ42-induced cytotoxicity. These findings underscore the potential of ALZ-801 as an effective DMT for APOE ε4 homozygous patients with AD.

Playing Around the Coumarin Core in the Discovery of Multimodal Compounds Directed at Alzheimer's-Related Targets: A Recent Literature Overview

Alzheimer's disease (AD) causes a great socioeconomic burden because of its increasing prevalence and the lack of effective therapies. The multifactorial nature of AD prompts researchers to search for new strategies for discovering disease-modifying therapeutics. To this extent, the multitarget approach holds the potential of synergic or cooperative activities arising from compounds that are properly designed to address two or more pathogenetic mechanisms. As a privileged and nature-friendly scaffold, coumarin has successfully been enrolled as the heterocyclic core in the design of multipotent anti-Alzheimer's agents. Herein, we comprehensively summarize the most recent literature (2018-2023), covering the rational design and the discovery of coumarin-containing multitarget directed ligands (MTDLs) whose anti-AD profile encompassed at least two different biological activities relevant for disease onset and progression. To enhance the clarity of presentation, synthetic coumarin-based MTDLs are categorized into four clusters based on their substitution pattern and reported bioactivities: (i) mono-, (ii) di-, and (iii) polysubstituted coumarins directed at protein targets, and (iv) coumarins directed at protein targets with additional metal-chelating features. Before discussing multimodal coumarins, the rationale for addressing each biological target is briefly presented.

Pathogenesis and therapeutic applications of microglia receptors in Alzheimer's disease

Microglia, the resident immune cells of the central nervous system, continuously monitor the brain's microenvironment through their array of specific receptors. Once brain function is altered, microglia are recruited to specific sites to perform their immune functions, including phagocytosis of misfolded proteins, cellular debris, and apoptotic cells to maintain homeostasis. When toxic substances are overproduced, microglia are over-activated to produce large amounts of pro-inflammatory cytokines, which induce chronic inflammatory responses and lead to neurotoxicity. Additionally, microglia can also monitor and protect neuronal function through microglia-neuron crosstalk. Microglia receptors are important mediators for microglia to receive external stimuli, regulate the functional state of microglia, and transmit signals between cells. In this paper, we first review the role of microglia-expressed receptors in the pathogenesis and treatment of Alzheimer's disease; moreover, we emphasize the complexity of targeting microglia for therapeutic interventions in neurodegenerative disorders to inform the discovery of new biomarkers and the development of innovative therapeutics.

Functional and effective EEG connectivity patterns in Alzheimer's disease and mild cognitive impairment: a systematic review

Background

Alzheimer's disease (AD) might be best conceptualized as a disconnection syndrome, such that symptoms may be largely attributable to disrupted communication between brain regions, rather than to deterioration within discrete systems. EEG is uniquely capable of directly and non-invasively measuring neural activity with precise temporal resolution; connectivity quantifies the relationships between such signals in different brain regions. EEG research on connectivity in AD and mild cognitive impairment (MCI), often considered a prodromal phase of AD, has produced mixed results and has yet to be synthesized for comprehensive review. Thus, we performed a systematic review of EEG connectivity in MCI and AD participants compared with cognitively healthy older adult controls.

Methods

We searched PsycINFO, PubMed, and Web of Science for peer-reviewed studies in English on EEG, connectivity, and MCI/AD relative to controls. Of 1,344 initial matches, 124 articles were ultimately included in the systematic review.

Results

The included studies primarily analyzed coherence, phase-locked, and graph theory metrics. The influence of factors such as demographics, design, and approach was integrated and discussed. An overarching pattern emerged of lower connectivity in both MCI and AD compared to healthy controls, which was most prominent in the alpha band, and most consistent in AD. In the minority of studies reporting greater connectivity, theta band was most commonly implicated in both AD and MCI, followed by alpha. The overall prevalence of alpha effects may indicate its potential to provide insight into nuanced changes associated with AD-related networks, with the caveat that most studies were during the resting state where alpha is the dominant frequency. When greater connectivity was reported in MCI, it was primarily during task engagement, suggesting compensatory resources may be employed. In AD, greater connectivity was most common during rest, suggesting compensatory resources during task engagement may already be exhausted.

Conclusion

The review highlighted EEG connectivity as a powerful tool to advance understanding of AD-related changes in brain communication. We address the need for including demographic and methodological details, using source space connectivity, and extending this work to cognitively healthy older adults with AD risk toward advancing early AD detection and intervention.

Targeting Amyloid Pathology in Early Alzheimer's: The Promise of Donanemab-Azbt

OBJECTIVE

The purpose of this review is to examine the potential role of donanemab-azbt in the treatment and management of early-stage Alzheimer's disease (AD), with a focus on its efficacy, safety, and clinical relevance based on data from key clinical trials.

DATA SOURCES

A comprehensive literature search of PubMed was conducted using relevant keywords such as "donanemab", "Alzheimer's disease", "Kisunla", "TRAILBLAZER clinical trials", and "amyloid-related imaging abnormalities (ARIA)". Additional data were extracted from clinical trial records (clinicaltrials.gov), conference abstracts, and product monographs.

STUDY SELECTION AND DATA EXTRACTION

Only English-language studies conducted in human populations were included. Clinical trials and peer-reviewed studies detailing the efficacy, safety, and mechanistic insights of donanemab-azbt were prioritized.

DATA SYNTHESIS

Key findings from the TRAILBLAZER series of clinical trials highlighted the potential of donanemab-azbt in slowing cognitive and functional decline in early-stage AD: (1) TRAILBLAZER-ALZ (Phase 2): This trial focused on participants with intermediate levels of tau protein. Results demonstrated a statistically significant slowing of cognitive and functional decline. (2) TRAILBLAZER-ALZ 2 (Phase 3): A large-scale, randomized, double-blind, placebo-controlled study confirmed the efficacy of donanemab-azbt in reducing amyloid plaque accumulation and cognitive decline. Key results included a 35% slowing of decline on the Integrated Alzheimer's Disease Rating Scale (iADRS) and a 36% slowing on the Clinical Dementia Rating-Sum of Boxes (CDR-SB). Additional secondary outcomes showed improvements in activities of daily living and reduced risk of disease progression. (3) TRAILBLAZER-ALZ 3: This ongoing trial is evaluating donanemab's potential in delaying or preventing Alois Alzheimer in cognitively normal individuals with amyloid plaques, broadening the scope of early intervention strategies. (4) TRAILBLAZER-ALZ 4: A head-to-head comparison with aducanumab revealed superior amyloid plaque clearance with donanemab. (5) TRAILBLAZER-ALZ 5: Currently recruiting, this trial aims to evaluate safety and efficacy across diverse populations with varying tau levels and comorbidities. (6) TRAILBLAZER-ALZ 6 (Phase 3b): This trial investigates modified dosing regimens to reduce ARIA while maintaining efficacy, particularly in populations with genetic risk factors like ApoE ε4 homozygotes.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Donanemab-azbt represents a promising treatment option for patients with early-stage AD. It specifically targets and reduces amyloid beta plaques, a hallmark of the disease, potentially slowing progression and preserving cognitive function. However, its administration requires careful patient selection, including genetic testing for ApoE ε4 status, to mitigate risks of ARIA. Furthermore, the findings emphasize the importance of close monitoring during treatment.

CONCLUSIONS

Donanemab-azbt offers a new avenue for managing early-stage AD, showing promise in reducing amyloid burden and slowing cognitive decline. While its efficacy and safety have been demonstrated in clinical trials, further research is essential to validate long-term outcomes, assess effectiveness across diverse populations, and refine dosing strategies to minimize side effects. With continued investigation, donanemab-azbt could significantly impact the clinical landscape of AD treatment.

Stress-related neurodegenerative diseases: Molecular mechanisms implicated in neurodegeneration and therapeutic strategies

Chronic stress is a striking cause of major neurodegenerative diseases disorders (NDDs). These diseases share several common mechanisms regarding to disease pathology, in spite of they have various properties and clinical manifestations. NDDs are defined by progressive cognitive decline, and stress contribute to the promotion and progression of disease. In addition, various pathways such as production of reactive oxygen species (ROS), mitochondrial dysfunction, and neurodegeneration are the main crucial hallmarks to develop common NDDs, resulting in neuronal cell death. Although the exact mechanisms of NDDs are underexplored, the potential neuroprotective critical role of such therapies in neuronal loss the treatment of NDDs are not clear. In this regard, researchers investigate the neuroprotective effects of targeting underlying cascade to introduce a promising therapeutic option to NDDs. Herein, we provide an overview of the role of non-pharmacological treatments against oxidative stress, mitochondrial symbiosis, and neuroinflammation in NDDs, mainly discussing the music, diet, and exercise effects of targeting pathways.

Deciphering the endogenous SUMO-1 landscape: a novel combinatorial peptide enrichment strategy for global profiling and disease association

Small ubiquitin-like modifier (SUMO) plays a pivotal role in diverse cellular processes and is implicated in diseases such as cancer and neurodegenerative disorders. However, large-scale identification of endogenous SUMO-1 faces challenges due to limited enrichment methods and its lower abundance compared to SUMO-2/3. Here we propose a novel combinatorial peptide strategy, combined with anti-adhesive polymer development, to enrich endogenous SUMO-1 modified peptides, revealing a comprehensive SUMOylation landscape. Utilizing phage display, we successfully identified a linear 12-mer and a cystine-linked cyclic 7-mer peptide ligand, specifically designed to target the C-terminal regions of SUMO-1 remnants. Building upon their high affinities and satisfactory complementarity, we developed the first artificial SUMO-1 enrichment materials, ultimately establishing a combinatorial peptide strategy that facilitates a comprehensive analysis of the endogenous SUMO-1 modified proteome in both cellular and tissue contexts. We successfully mapped 1312 SUMOylation sites in HeLa cells and 1365 along with 991 endogenous SUMOylation proteins in Alzheimer's disease (AD) mouse brain tissues. Notably, our method uncovered a significant upregulation of SUMO-1 in AD mouse brain tissue, providing new insights into SUMOylation's role in disease. Overall, this work represents the most thorough exploration of SUMO-1 modified proteomics and offers robust tools for elucidating the roles of SUMO-1's biological significance.

Suppressing APOE4-induced neural pathologies by targeting the VHL-HIF axis

The ε4 variant of human apolipoprotein E (APOE4) is a key genetic risk factor for neurodegeneration in Alzheimer's disease and elevated all-cause mortality in humans. Understanding the factors and mechanisms that can mitigate the harmful effects of APOE4 has significant implications. In this study, we find that inactivating the VHL-1 (Von Hippel-Lindau) protein can suppress mortality, neural and behavioral pathologies caused by transgenic human APOE4 in Caenorhabditis elegans. The protective effects of VHL-1 deletion are recapitulated by stabilized HIF-1 (hypoxia-inducible factor), a transcription factor degraded by VHL-1. HIF-1 activates a genetic program that safeguards against mitochondrial dysfunction, oxidative stress, proteostasis imbalance, and endolysosomal rupture-critical cellular events linked to neural pathologies and mortality. Furthermore, genetic inhibition of Vhl reduces cerebral vascular injury and synaptic lesions in APOE4 mice, suggesting an evolutionarily conserved mechanism. Thus, we identify the VHL-HIF axis as a potent modulator of APOE4-induced neural pathologies and propose that targeting this pathway in nonproliferative tissues may curb cellular damage, protect against neurodegeneration, and reduce tissue injuries and mortality.

Sleep-wake variation in body temperature regulates tau secretion and correlates with CSF and plasma tau

Sleep disturbance is bidirectionally associated with an increased risk of Alzheimer's disease and other tauopathies. While the sleep-wake cycle regulates interstitial and cerebrospinal fluid (CSF) tau levels, the underlying mechanisms remain unknown. Understanding these mechanisms is crucial, given the evidence that tau pathology spreads through neuron-to-neuron transfer, involving the secretion and internalization of pathological tau forms. Here, we combined in vitro, in vivo, and clinical methods to reveal a pathway by which changes in body temperature (BT) over the sleep-wake cycle modulate extracellular tau levels. In mice, a higher BT during wakefulness and sleep deprivation increased CSF and plasma tau levels, while also upregulating unconventional protein secretion pathway I (UPS-I) events including (a) intracellular tau dephosphorylation, (b) caspase 3-mediated cleavage of tau (TauC3), and (c) membrane translocation of tau through binding to phosphatidylinositol 4,5-bisphosphate (PIP2) and syndecan 3. In humans, the increase in CSF and plasma tau levels observed after wakefulness correlated with BT increases during wakefulness. By demonstrating that sleep-wake variation in BT regulates extracellular tau levels, our findings highlight the importance of thermoregulation in linking sleep disturbances to tau-mediated neurodegeneration and the preventative potential of thermal interventions.

Transcriptome analysis of early- and late-onset Alzheimer's disease in Korean cohorts

INTRODUCTION

The molecular mechanisms underlying early-onset Alzheimer's disease (EOAD) and late-onset Alzheimer's disease (LOAD) remain incompletely understood, particularly in Asian populations.

METHODS

RNA-sequencing was carried out on blood samples from 248 participants in the Seoul National University Bundang Hospital cohort to perform differential gene expression (DGE) and weighted gene co-expression network analysis. Findings were replicated in an independent Korean cohort (N = 275).

RESULTS

DGE analysis identified 18 and 88 dysregulated genes in EOAD and LOAD, respectively. Network analysis identified a LOAD-associated module showing a significant enrichment in pathways related to mitophagy, 5' adenosine monophosphate-activated protein kinase signaling, and ubiquitin-mediated proteolysis. In the replication cohort, downregulation of SMOX and PLVAP in LOAD was replicated, and the LOAD-associated module was highly preserved. In addition, SMOX and PLVAP were associated with brain amyloid beta deposition.

DISCUSSION

Our findings suggest distinct molecular signatures for EOAD and LOAD in a Korean population, providing deeper understanding of their diagnostic potential and molecular mechanisms.

HIGHLIGHTS

Analysis identified 18 and 88 dysregulated genes in early-onset Alzheimer's disease (EOAD) and late-onset Alzheimer's disease (LOAD), respectively. Expression levels of SMOX and PLVAP were downregulated in LOAD. Expression levels of SMOX and PLVAP were associated with brain amyloid beta deposition. Pathways including mitophagy and 5' adenosine monophosphate-activated protein kinase signaling were enriched in a LOAD module. A LOAD module was highly preserved across two independent cohorts.

Lysosome-Targeting Protein Degradation Through Endocytosis Pathway Triggered by Polyvalent Nano-Chimera for AD Therapy

The excessive up-regulation of receptor for advanced glycation end products (RAGE), a well-known pathological marker, drives the onset and progression of Alzheimer's disease. Although lysosome-targeting protein degradation has emerged as an effective therapeutic modality, the limited lysosome-sorting efficacy greatly hindered the degradation efficiency of target proteins. Herein, a lysosome-shuttle-like nano-chimera (endoTAC) is proposed based on polyvalent receptor binding mode for enhanced RAGE degradation as well as precise drug delivery. The endoTAC shows a high affinity to RAGE and enhances RAGE degradation due to its polyvalent-interaction with RAGE. Additionally, endoTAC features increased accumulation in diseased brain and shows promise as a precise brain delivery system. After loading with simvastatin, the SV@endoTAC proves to successfully reverse pathological features both in vitro and in vivo. The work proposes that the combination of a lysosome-targeting chimera and an effective drug delivery system can be promising in Alzheimer's disease therapy.