Search Results (283)

Alzheimer’s disease (AD) is a progressive neurological condition with limited effective pharmaceutical treatments, often accompanied by side effects. This has increased interest in plant-based alternatives. This study examined the cognitive effects of a Natural Polyherbal Extract (NPX) on scopolamine-induced memory deficits in mice. Male C57BL/6 mice (10 weeks old, n = 36) were divided into four groups: control (saline), scopolamine (1 mg/kg, i.p.), tacrine (10 mg/kg, oral), and NPX (1000 mg/kg, oral). NPX and tacrine were administered daily by oral gavage for two weeks. Cognitive function was assessed weekly using the Y-maze task. Brain tissues were collected for biochemical analysis, including AChE activity and immunohistochemical detection of neurodegeneration-related markers. Results: Mice treated with NPX demonstrated improved spontaneous alternation behavior compared to the scopolamine group. NPX also significantly reduced acetylcholinesterase activity. Immunohistochemistry revealed decreased expression of amyloid-beta (Aβ) and caspase-3, with enhanced choline acetyltransferase levels. These outcomes were comparable to those observed in the tacrine-treated group. Conclusions: NPX alleviated scopolamine-induced memory impairment through enhancement of cholinergic signaling and mitigation of neurodegenerative markers. The findings suggest that NPX may serve as a promising plant-derived candidate for managing memory-related disorders, including AD. Full article

Phlorizin (PHZ) is a glucoside of phloretin, belonging to the dihydrochalcone class within flavonoids; It is one of the active ingredients of the plant Cynomorium, and it has been shown that PHZ can regulate lipid metabolism disorders as well as having anti-aging properties. However, no studies have investigated whether PHZ ameliorates Aβ-induced toxicity in Alzheimer’s disease (AD) by regulating fatty acid β-oxidation. This study aims to investigate the effects of PHZ on the regulation of fatty acid β-oxidation and resistance to Aβ-associated toxicity on the AD Caenorhabditis elegans and the mechanisms of action. Wild-type N2 and AD model CL4176 C. elegans were used; lifespan, heat stress resistance, chronic paraquat stress, reactive oxygen species (ROS), behavioral performance, and lipofuscin accumulation assays were examined to evaluate the anti-aging effects; and non-esterified fatty acid (NEFA), triglyceride (TG) and lipidomic contents were quantified after PHZ treatment. The detection of genes related to fatty acid β-oxidation pathways was performed using qRT-PCR. nhr-49 knockout mutant RB1716; and GFP-binding mutants PMD150 WBM170 were used to observe the effect of PHZ on NHR-49 pathways, and molecular docking studies were performed by combining PHZ with NHR-49 proteins. Results showed that PHZ improved worms’ survival and delayed senescence, as demonstrated by enhanced performance in lifespan, heat stress, ROS, and paraquat assays and chronic paraquat assays; PHZ also reduced lipid accumulation in worms, affected the unsaturated fatty acid pathway, and significantly increased the expression of fatty acid metabolism-related genes nhr-49, acs-2, and cpt-5, and can be tightly coupled to NHR-49 targets. PHZ may play an anti-Aβ toxicity role by regulating lipid metabolism disorders through the NHR-49—related pathway and anti-aging in AD worms. Full article

Alzheimer’s disease, a neurodegenerative brain disorder leading to the progressive decline in cognitive functions, is the most common type of dementia. The main risk factor for its development is aging. Recent studies indicate that cellular senescence mechanisms are among the major factors in a heterogeneous aging process. Cellular senescence is characterized by a permanent proliferative arrest. Many factors might initiate senescence, for example, damage of DNA, shortening of telomeres, dysfunction of mitochondria, and oncogene activation. These processes lead to alterations in the morphology and function of senescent cells. Research is still ongoing to identify one universal marker that could detect senescent cells and distinguish them from other non-proliferating cells. Those cells are involved in age-related pathologies through many heterogeneous processes, including secretion of pro-inflammatory senescence-associated secretory phenotype factors, which affect the brain differently. Alzheimer’s disease is an example of a neurodegenerative condition connected to cellular senescence. Senescent cells have been demonstrated to accumulate near Aβ plaques and neurofibrillary tangles. In this review, the multifactorial connection between Alzheimer’s disease and cellular senescence is discussed, including topics such as senescence of astrocytes, defective mitochondria, dysregulation of cellular autophagy, and the role of senescent microglia. Full article

Alzheimer’s disease (AD) is a progressive neurodegenerative condition representing the most common cause of dementia and currently affects millions of people worldwide. The clinical presentation includes memory impairment, cognitive decline, and neuropsychiatric symptoms, reflecting pathological hallmarks such as β-amyloid (Aβ) plaques, neurofibrillary tangles, synaptic dysfunction, and neuroinflammation. Despite being the gold standard for detecting amyloid and tau pathologies in vivo, cerebrospinal fluid (CSF) biomarkers and positron emission tomography (PET) imaging are not widely used in the clinical setting because of invasiveness, high costs, and restricted accessibility. Recent advances in blood-based biomarkers offer a promising and minimally invasive tool for early detection, diagnosis, and monitoring of AD. Ultra-sensitive analytical platforms, including single-molecule arrays (Simoa) and immunoprecipitation-mass spectrometry, now enable reliable quantification of plasma Aβ isoforms, phosphorylated tau variants (p-Tau181, p-Tau217, p-Tau231), neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP). In addition, blood biomarkers reflecting oxidative stress, neuroinflammation, synaptic disruption and metabolic dysfunction are under active investigation. This narrative review synthesizes current evidence on blood-based biomarkers in AD, emphasizing their biological relevance, diagnostic accuracy, and clinical applications. Finally, we highlight forthcoming challenges, such as standardization, and future directions, including the use of artificial intelligence in precision medicine. Full article

The design and synthesis of a small library of 2-styrylquinoline derivatives containing a push-pull system, aimed at displacing their fluorescence emission towards the NIR region, is described. We describe here their synthesis, fluorescent characterization and pharmacological evaluation against different amyloid proteins. Their study showed that these compounds are capable to change their spectroscopic properties upon protein interaction, resulting in changes in the absorption and emission wavelengths, together with increased fluorescence intensity. They also showed sensitivity to pH and environment polarity, exhibiting red shifts in lower polarity environments with regard to aqueous media. Inner charge transfer is observed and employed for detecting the interaction of these compounds with protein aggregates. The study of the alterations in the fluorescence intensity allows to calculate the dissociation constant values for the protein-sensor interaction. These spectroscopic results were the basis for the use of these compounds to visualize β-amyloid plates with selectivity over phosphorylated tau in samples of cerebral tissue from deceased Alzheimer patients under fluorescence microscopy, using immunofluorescence techniques. Pharmacological assays showed that the compounds inhibit the aggregation of the Aβ_1–42 and AcPHF6 peptides, representing tau protein. They also showed neuroprotective activity following okadaic acid insult. Full article

Alzheimer’s disease (AD) has emerged as a global health threat that demands early detection to seize the optimal intervention opportunity. Central nervous system (CNS)-derived extracellular vesicles (EVs), lipid-bilayer nanoparticles released by CNS cells, carry key biomolecules involved in AD pathology, positioning them as a promising source of biomarkers for early detection. Current breakthroughs in EV-based isolation and detection technologies have opened up the possibility of early, accurate AD diagnosis. This review summarizes their multifaceted roles in AD pathogenesis, including amyloid-β (Aβ) aggregation, tau propagation, neuroinflammation, and synaptic dysfunction, and highlights neuron- and glia-derived EV biomarkers with translational potential. We further outline recent advances in EV isolation techniques—including density-, size-, charge/dielectric-, immunoaffinity-, and acoustics-based approaches—and emerging detection platforms such as fluorescence, surface plasmon resonance (SPR), surface-enhanced Raman spectroscopy (SERS), electrochemical, and nanomechanical sensors for sensitive, multiplex AD diagnostics. Finally, we discuss key challenges, including standardization, sensitivity, and high-throughput adaptation, and explore future directions such as automated microfluidics and single-vesicle analysis. CNS-derived EVs hold significant promise as minimally invasive, next-generation tools for early AD detection and precision medicine. Full article

One hundred and eighteen years have passed since Alzheimer’s disease (AD) was first diagnosed by Alois Alzheimer as a multifactorial and complex neurodegenerative disorder with psychiatric components. It is inaugurated by a cascade of events initiating from amnesic-type memory impairment leading to the gradual loss of cognitive and executive capacities. Pathologically, there is overwhelming evidence that clumps of misfolded amyloid-β (Aβ) and hyperphosphorylated tau protein aggregate in the brain. These pathological processes lead to neuronal loss, brain atrophy, and gliosis culminating in neurodegeneration and fueling AD. Thus, at a basic level, abnormality in the brain’s protein function is observed, causing disruption in the brain network and loss of neural connectivity. Nevertheless, AD is an aging disorder caused by a combination of age-related changes and genetic and environmental factors that affect the brain over time. Its mysterious pathology seems not to be limited to senile plaques (Aβ) and neurofibrillary tangles (tau), but to a plethora of substantial and biological processes, which have also emerged in its pathogenesis, such as a breakdown of the blood–brain barrier (BBB), patients carrying the gene variant APOE4, and the immuno-senescence of the immune system. Furthermore, type 2 diabetes (T2DM) and metabolic syndrome (MS) have also been observed to be early markers that may provoke pathogenic pathways that lead to or aggravate AD progression and pathology. There are numerous substantial AD features that require more understanding, such as chronic neuroinflammation, decreased glucose utilization and energy metabolism, as well as brain insulin resistance (IR). Herein, we aim to broaden our understanding and to connect the dots of the multiple comorbidities and their cumulative synergistic effects on BBB dysfunction and AD pathology. We shed light on the path-physiological modifications in the cerebral vasculature that may contribute to AD pathology and cognitive decline prior to clinically detectable changes in amyloid-beta (Aβ) and tau pathology, diagnostic biomarkers of AD, neuroimmune involvement, and the role of APOE4 allele and AD–IR pathogenic link—the shared genetics and metabolomic biomarkers between AD and IR disorders. Investment in future research brings us closer to knowing the pathogenesis of AD and paves the way to building prevention and treatment strategies. Full article

Glial fibrillary acidic protein (GFAP) has been shown to be a reliable biomarker for detecting neurological disorders. Recently, we developed the Lumipulse G GFAP plasma assay, which is a commercially available tool. Compared to existing assays, the LUMIPLSE G platform offers the high-throughput, rapid, and fully automated quantification of biomarkers, enabling more standardized and accessible clinical study. In this study, we evaluated this assay using cerebrospinal fluid (CSF) samples. Assessing GFAP in CSF may provide more direct insights into central nervous system pathology than plasma and could improve the characterization of Alzheimer’s disease (AD) stages and support treatment monitoring. The LUMIPULSE G system is a chemiluminescent enzyme immunoassay (CLEIA) platform equipped with full automation, utilizing specialized cartridges to process samples within 30 min. The assay, which employs a pair of proprietary monoclonal antibodies targeting GFAP, was evaluated for clinical performance using 30 CSF samples from patients diagnosed with AD, patients with mild cognitive impairment (MCI), and cognitively unimpaired (CU) individuals, with 10 samples from each group. In addition, levels of β-amyloid 1–40 (Aβ40), β-amyloid 1–42 (Aβ42), and pTau181 were simultaneously measured. The Lumipulse G GFAP assay significantly differentiated (p < 0.05) between the amyloid accumulation and non-amyloid accumulation groups, as classified based on the CSF Aβ test. Furthermore, GFAP showed a moderate correlation with pTau181 (r = 0.588), as determined based on Spearman’s rank correlation coefficient. Moreover, receiver operating characteristic (ROC) analysis was performed to determine the performance of GFAP in distinguishing amyloid-positive and amyloid-negative subjects, with an area under the curve (AUC) of 0.72 (0.50–0.93). When stratified by CSF pTau181 positivity, GFAP demonstrated an improved diagnostic accuracy, achieving an AUC of 0.86 (95% CI: 0.68–1.00). This study demonstrates that the Lumipulse G GFAP assay, when applied to CSF samples, has the potential to differentiate AD from non-AD cases, particularly suggesting its utility in detecting tau-related pathology. While GFAP has previously been established as a biomarker for AD, our findings highlight that combining GFAP with other biomarkers such as Aβ40, Aβ42, and pTau181 may enhance the understanding of AD pathogenesis, disease staging, and possibly treatment responses. These findings suggest that GFAP may serve as a complementary biomarker reflecting astroglial reactivity associated with tau positivity, alongside established biomarkers such as Aβ40, Aβ42, and pTau181. However, since GFAP levels may also be elevated in other neurological disorders beyond AD, further investigation into these conditions is required. Full article

Apelin-13, a neuropeptide, has been recognized for its neuroprotective properties. Our previous study found apelin-13 improves cognitive function in Alzheimer’s disease (AD) rats by inhibiting neuroinflammation through upregulation of BDNF/TrkB signaling pathway. However, the precise mechanism by which apelin-13 modulates BDNF remains unclear. Thus, this study aimed to unravel the specific regulatory mechanism by which apelin-13 regulates BDNF. Bilaterally intracerebroventricular injection with Aβ25–35 was used to establish an in vivo model of AD. For the generation of METTL3 KO rats, the Crispr/Cas9 method was applied. PC12 cells were treated with Aβ25–35 to establish an in vitro model of AD. The cognitive function of the rats was evaluated with the Morris water maze and the novel object recognition test. Hippocampal damage and neuron loss were detected through H&E and immunofluorescent staining. METTL3, BDNF, TrkB, and p-TrkB were examined by Western blotting. Inflammation-related cytokines, IBA1, GFAP, IL-1β, and TNF-α were detected by Western blotting, immunofluorescent staining, ELISA, and qRT-PCR. m6A modification level was evaluated through MeRIP. A flow cytometer was applied to evaluate cell apoptosis. Cell proliferation was examined using MTT. m6A methylation inhibitor DAA reverses the improvement effect of apelin-13 on cognitive function, hippocampal nerve damage, neuron loss, and neuroinflammation in Aβ25–35-treated rats. Further results showed that apelin-13 upregulated METTL3, BDNF-AS m6A methylation, inhibited BDNF-AS expression, and subsequently upregulated BDNF/TrkB signaling pathway and reduced neuroinflammation in in vivo and in vitro AD models in a dose-dependent manner. Knockdown of METTL3 abolished apelin-13’s improvement effect in AD rats. Apelin-13-mediated upregulation of METTL3 enhances neuroinflammation inhibition and BDNF/TrkB signaling pathway via m6A-dependent downregulation of lncRNA BDNF-AS, thus ameliorating AD. Our study offers novel insights into the pathogenesis of AD and identifies potential drug targets for its treatment. Full article

Growing evidence suggests that Reelin signals and cleavages are affected in neurodegenerative diseases, prospecting a potential role for Reelin in the pathogenesis of neurodegenerative processes occurring in insulted retinas. We sought to determine whether Reelin, Aβ1-42, FTH1 and TAU proteins accumulate in ocular fluids of idiopathic epiretinal membrane (iERM) specimens and whether such accumulations depend on disease severity. Comparisons and correlation studies were used to verify the hypothesis of a Reelin, Aβ1-42, TAU and FTH1 marker expressions in this vitreoretinal disease, extending the knowledge on the pathological spectrum of neurodegenerative eye diseases. Aqueous, vitreous and peeled-off ERM samples were collected from patients who had undergone vitrectomy and grouped according to disease severity. We found out that Reelin and Aβ1-42 were expressed in ocular fluids and affected ERMs depending on disease severity. At stage 3, higher Reelin and Aβ1-42 immunofluorescence staining was detected in ERMs, in agreement with the higher Reelin, Aβ1-42, FTH1 and TAU transcript expressions by RT-PCR. Differential expressions of transcripts specific to Aβ1-42, FTH1, GFAP and TAU occurred in vitreal hyalocytes and astrocytes, which selectively responded to vitreal exposure. This is the first study reporting the association between Reelin and ERM disease, highlighting the potential role of Reelin in neurodegenerating and Drusen-affected retinas. The potential association of neurodegenerative mediators with ERM would suggest that part of the neuronal damage activated at the vitreoretinal interphase might be driven by Reelin. Full article

Background and Objectives: Over the past few years, there has been a significant shift in focus from developing better diagnostic tools to detecting Alzheimer’s disease (AD) earlier and initiating treatment interventions. This review will explore four main objectives: (a) the role of biomarkers in enhancing the diagnostic accuracy of AD, highlighting the major strides that have been made in recent years; (b) the role of neuropsychological testing in identifying biomarkers of AD, including the relationship between cognitive performance and neuroimaging biomarkers; (c) the amyloid hypothesis and possible molecular mechanisms of AD; and (d) the innovative AD therapeutics and the challenges and limitations of AD research. Materials and Methods: We have searched PubMed and Scopus databases for peer-reviewed research articles published in English (preclinical and clinical studies as well as relevant reviews and meta-analyses) investigating the molecular mechanisms, biomarkers, and treatments of AD. Results: Genome-wide association studies (GWASs) discovered 37 loci associated with AD risk. Core 1 biomarkers (α-amyloid Aβ42, phosphorylated tau, and amyloid PET) detect early AD phases, identifying both symptomatic and asymptomatic individuals, while core 2 biomarkers inform the short-term progression risk in individuals without symptoms. The recurrent failures of Aβ-targeted clinical studies undermine the amyloid cascade hypothesis and the objectives of AD medication development. The molecular mechanisms of AD include the accumulation of amyloid plaques and tau protein, vascular dysfunction, neuroinflammation, oxidative stress, and lipid metabolism dysregulation. Significant advancements in drug delivery technologies, such as focused Low-Ultrasound Stem, T cells, exosomes, nanoparticles, transferin, nicotinic and acetylcholine receptors, and glutathione transporters, are aimed at overcoming the BBB to enhance treatment efficacy for AD. Aducanumab and Lecanemab are IgG1 monoclonal antibodies that retard the progression of AD. BACE inhibitors have been explored as a therapeutic strategy for AD. Gene therapies targeting APOE using the CRISPR/Cas9 genome-editing system are another therapeutic avenue. Conclusions: Classic neurodegenerative biomarkers have emerged as powerful tools for enhancing the diagnostic accuracy of AD. Despite the supporting evidence, the amyloid hypothesis has several unresolved issues. Novel monoclonal antibodies may halt the AD course. Advances in delivery systems across the BBB are promising for the efficacy of AD treatments. Full article

With a rapidly growing incidence and prevalence, Alzheimer’s disease (AD) is rapidly becoming one of the most disabling, lethal, and expensive diseases of the century. To diagnose AD as early as possible, the scientific world struggles to find reliable and non-invasive biomarkers that could predict the conversion of mild cognitive impairment to AD and delineate the ongoing pathogenic vicious pathways to be targeted with therapy. Research supports the use of blood biomarkers, such as Aβ_1-42/Aβ_1-40 ratio, phosphorylated tau181, and p-tau217 for diagnostic purposes, although the cut-offs are not clearly established and can depend on the assays used. For more accurate diagnosis, markers of neurodegeneration (neurofilament light) and neuroinflammation (glial fibrillary acidic protein) could be introduced in the biomarker panel. The recent approval of the Lumipulse G p-tau217/Aβ_1-42 plasma ratio by the FDA for the early detection of amyloid plaques associated with Alzheimer’s disease in adult patients, aged 55 years and older, exhibiting signs and symptoms of the disease represents a significant advancement in the diagnosis of Alzheimer’s disease, offering a more accessible and less invasive way to diagnose this devastating disease and allow potentially earlier access to treatment options. Full article

Neurodegenerative diseases (NDDs) such as Alzheimer’s, Parkinson’s, ALS, and Huntington’s pose a growing global challenge due to their complex pathobiology and aging demographics. Once considered as cellular debris, small extracellular vesicles (sEVs) are now recognized as active mediators of intercellular signaling in NDD progression. These nanovesicles (~30–150 nm), capable of crossing the blood–brain barrier, carry pathological proteins, RNAs, and lipids, facilitating the spread of toxic species like Aβ, tau, TDP-43, and α-synuclein. sEVs are increasingly recognized as valuable diagnostic tools, outperforming traditional CSF biomarkers in early detection and disease monitoring. On the therapeutic front, engineered sEVs offer a promising platform for CNS-targeted delivery of siRNAs, CRISPR tools, and neuroprotective agents, demonstrating efficacy in preclinical models. However, translational hurdles persist, including standardization, scalability, and regulatory alignment. Promising solutions are emerging, such as CRISPR-based barcoding, which enables high-resolution tracking of vesicle biodistribution; AI-guided analytics to enhance quality control; and coordinated regulatory efforts by the FDA, EMA, and ISEV aimed at unifying identity and purity criteria under forthcoming Minimal Information for Studies of Extracellular Vesicles (MISEV) guidelines. This review critically examines the mechanistic roles, diagnostic potential, and therapeutic applications of sEVs in NDDs, and outlines key strategies for clinical translation. Full article

Amyloid-β (Aβ) aggregates are considered as the important factors of Alzheimer’s disease (AD). Multifunctional materials have shown significant effects in the diagnosis and treatment of AD by modulating the aggregation of Aβ and production of reactive oxygen species (ROS). Compared to traditional surgical treatment and radiotherapy, phototherapy has the advantages, including short response time, significant efficacy, and minimal side effects in disease diagnosis and treatment. Recent studies have shown that local thermal energy or singlet oxygen generated by irradiating certain organic molecules or nanomaterials with specific laser wavelengths can effectively degrade Aβ aggregates and depress the generation of ROS, promoting progress in AD diagnosis and therapy. Herein, we outline the development of photothermal therapy (PTT) and photodynamic therapy (PDT) strategies for the diagnosis and therapy of AD by modulating Aβ aggregation. The materials mainly include organic photothermal agents or photosensitizers, polymer materials, metal nanoparticles, quantum dots, carbon-based nanomaterials, etc. In addition, compared to traditional fluorescent dyes, aggregation-induced emission (AIE) molecules have the advantages of good stability, low background signals, and strong resistance to photobleaching for bioimaging. Some AIE-based materials exhibit excellent photothermal and photodynamic effects, showing broad application prospects in the diagnosis and therapy of AD. We further summarize the advances in the detection of Aβ aggregates and phototherapy of AD using AIE-based materials. Full article

Alzheimer’s disease (AD) is the most prevalent neurodegenerative disorder and represents a major public health challenge. With increasing life expectancy, the incidence of AD has also increased, highlighting the need for early diagnosis and improved monitoring. Traditionally, diagnosis has relied on clinical symptoms and neuroimaging; however, the introduction of biomarkers has revolutionized disease assessment. Traditional biomarkers, including the Aβ42/Aβ40 ratio, phosphorylated tau (p-Tau181, p-Tau217, and p-Tau231), total tau (t-tau), and neurofilament light chain (NfL), are fundamental for staging AD progression. Updated guidelines introduced the ATX(N) model, which extends biomarker classification to include additional promising biomarkers, such as SNAP-25, YKL-40, GAP-43, VILIP-1, progranulin (PGRN), TREM2, IGF-1, hFABP, MCP-1, TDP-43, and BDNF. Recent advancements have allowed for the detection of these biomarkers not only in CSF but also in plasma and neuron-derived exosomes, offering less invasive and more accessible diagnostic options. This review explores established and emerging biomarkers and emphasizes their roles in early diagnosis, patient stratification, and precision medicine. Full article