Oxidative Stress, Synaptic Dysfunction, and Alzheimer's Disease

Mitochondrial DNA editing: Key to the treatment of neurodegenerative diseases

Neuronal death is associated with mitochondrial dysfunction caused by mutations in mitochondrial DNA. Mitochondrial DNA becomes damaged when processes such as replication, repair, and nucleotide synthesis are compromised. This extensive accumulation of damaged mitochondrial DNA subsequently disrupts the normal function of mitochondria, leading to aging, degeneration, or even death of neurons. Mitochondrial dysfunction stands as a pivotal factor in the development of neurodegenerative diseases, including Parkinson's disease, Alzheimer's disease, Huntington's disease, and amyotrophic lateral sclerosis. Recognizing the intricate nature of their pathogenesis, there is an urgent need for more effective therapeutic interventions. In recent years, mitochondrial DNA editing tools such as zinc finger nucleases, double-stranded DNA deaminase toxin A-derived cytosine base editors, and transcription activator-like effector ligand deaminases have emerged. Their emergence will revolutionize the research and treatment of mitochondrial diseases. In this review, we summarize the advancements in mitochondrial base editing technology and anticipate its utilization in neurodegenerative diseases, offering insights that may inform preventive strategies and therapeutic interventions for disease phenotypes.

Unraveling the cGAS-STING pathway in Alzheimer's disease: A new Frontier in neuroinflammation and therapeutic strategies

Alzheimer's disease (AD) is the most prevalent type of neurological disorder characterized by cognitive decline and memory loss, marked by the accumulation of amyloid beta (Aβ) plaques and hyperphosphorylated tau protein, causing extensive neuronal death and neuroinflammation. There is growing evidence that AD development extends beyond the neuronal compartment and has a major impact on the immunological functions of the brain. The cyclic GMP-AMP synthase (cGAS) detects cytosolic DNA, including pathogenic foreign DNA and self-DNA from cellular injury, triggering a type I interferon (IFN-I) response through activation of the stimulator of interferon genes (STING). The activation of the cGAS-STING pathway in response to mitochondrial dysfunction drives neuroinflammation in AD, which is mediated by the release of IFN-I cytokines. Furthermore, the release of oxidized mtDNA is necessary for the stimulation of the nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome, which is a family of protein complexes that macrophages can produce to induce inflammation. AD becomes severe by the stimulation of the cGAS-STING pathway, which results in sterile inflammation and microglial dysfunction. This review aims to explore the potential impact of the cGAS-STING signaling pathway in the pathogenesis and progression of AD. Additionally; after overviewing recent findings, this article highlights the molecular mechanism involved in the onset of disease and its modulation regarding the therapeutic approach of AD. Finally, deliberated a deep insight, the cGAS-STING axis could provide novel therapeutic avenues for slowing or halting the progression of AD, thereby offering new prospects for treatment development.

Unveiling the Involvement of Herpes Simplex Virus-1 in Alzheimer's Disease: Possible Mechanisms and Therapeutic Implications

Viruses pose a significant challenge and threat to human health, as demonstrated by the current COVID-19 pandemic. Neurodegeneration, particularly in the case of Alzheimer's disease (AD), is significantly influenced by viral infections. AD is a neurodegenerative disease that affects people of all ages and poses a significant threat to millions of individuals worldwide. The precise mechanism behind its development is not yet fully understood; however, the emergence and advancement of AD can be hastened by various environmental factors, such as bacterial and viral infections. There has been a longstanding suspicion that the herpes simplex virus-1 (HSV-1) may have a role to play in the development or advancement of AD. Reactivation of HSV-1 could potentially lead to damage to neurons, either by direct means or indirectly by triggering inflammation. This article provides an overview of the connection between HSV-1 infections and immune cells (astrocytes, microglia, and oligodendrocytes) in the progression of AD. It summarizes recent scientific research on how HSV-1 affects neurons, which could potentially shed light on the clinical features and treatment options for AD. In addition, the paper has explored the impact of HSV-1 on neurons and its role in various aspects of AD, such as Aβ secretion, tau hyperphosphorylation, metabolic dysregulation, oxidative damage, apoptosis, and autophagy. It is believed that the immune response triggered by HSV-1 reactivation plays a role in the development of neurodegeneration in AD. Despite the lack of a cure for AD, researchers have made significant efforts to study the clinical and pathological aspects of the disease, identify biomarkers, and gain insight into its underlying causes. The goal is to achieve early diagnosis and develop treatments that can modify the progression of the disease. The current article discusses the most promising therapy for combating the viral impacts, which provides additional evidence for the frequent reactivations of latent HSV-1 in the AD brain. However, further research is still required to establish the molecular and cellular mechanisms underlying the development of AD through the reactivation of HSV-1. This could potentially lead to new insights in drug development aimed at preventing HSV-1 reactivation and the subsequent development and progression of AD.

Cyclophilin D (CypD) ablation prevents neurodegeneration and cognitive damage induced by caspase-3 cleaved tau

Abnormal tau modifications are one of the main contributors to neurodegenerative processes present during Alzheimer's disease (AD). In this context, truncated tau by caspase-3, a pathological tau form, affects mitochondrial function and antioxidant regulation, contributing to synaptic and cognitive impairment in AD mouse models. We previously showed that the presence of caspase-3 cleaved tau promotes mitochondrial impairment in neuronal cells, where Cyclophilin-D (CypD) protein could be a crucial element. CypD is considered the master regulator of mitochondrial permeability transition pore (mPTP) opening, and its ablation prevents neurodegenerative and cognitive damage induced by β-amyloid in mouse models of AD. However, the possible role of CypD in the neurodegenerative processes mediated by caspase-3-cleaved tau has not been explored. Here, we use tau (-/-) and CypD (-/-) knock-out mice that were subjected to right-side hippocampal stereotaxic injection to induce GFP (AAV-Syn-GFP), full-length (AAV-Syn-GFP-T4) or caspase-3-cleaved (AAV-Syn-GFP-T4C3) tau expression. Then, cognitive performance, synaptic architecture, and hippocampal mitochondrial function were evaluated two months later. We observed that caspase-3 cleaved tau expression inducing cognitive decline, vesicle and synaptic protein deregulation, and mitochondrial impairment generated by the mPTP opening. More interestingly, when caspase-3 cleaved tau was expressed in the hippocampus of CypD (-/-) mice, cognitive decline, synaptic impairment, and mitochondrial damage mediated by mPTP were prevented, demonstrating a novel role of CypD in neurodegenerative changes induced by truncated tau in AD.

Gastrointestinal Dysfunction and Low-Grade Inflammation Associate With Enteric Neuronal Amyloid-β in a Model for Amyloid Pathology

BACKGROUND

Patients suffering from Alzheimer's disease, a progressive neurodegenerative disorder involving cognitive decline and memory impairment, often present with gastrointestinal comorbidities. Accumulating data also indicate that alterations in the gut can modulate Alzheimer's disease pathology, highlighting the need to better understand the link between gastrointestinal abnormalities and neurodegeneration in the brain.

METHODS

To disentangle the pathophysiology of gastrointestinal dysfunction in Alzheimer's disease, we conducted a detailed pathological characterization of the gastrointestinal tract of 5xFAD mice by performing histological analyses, gene expression studies, immunofluorescence labeling and gut function assays.

RESULTS

We found that 5xFAD mice have elevated levels of intestinal amyloid precursor protein and accumulate amyloid-β in enteric neurons. Histopathology revealed that this is associated with mild intestinal inflammation and fibrosis and accompanied by increased expression of proinflammatory cytokines. While overall enteric nervous system composition and organization appeared unaffected, 5xFAD mice have faster gastrointestinal transit.

CONCLUSION

Our findings indicate that amyloid-β accumulation in enteric neurons is associated with low-grade intestinal inflammation and altered motility and suggest that peripheral pathology may cause gastrointestinal dysfunction in Alzheimer's disease patients.

Hepcidin modifies the relationship between anemia, erythrocyte indices, and neurocognitive performance in virally suppressed people with HIV

OBJECTIVE

Neurocognitive impairment in people with HIV (PWH) is associated with erythrocyte indices, which may serve as indicators of iron metabolism, inflammation, and related factors. Erythropoiesis requires iron, regulated by a multifaceted system of peptide hormones, including hepcidin. This study postulated that hepcidin might modify the relationship between erythrocyte indices and neurocognitive performance in PWH.

METHODS

Plasma hepcidin and erythrocyte indices were quantified in 88 virally suppressed PWH who underwent comprehensive neurocognitive assessments. Global neurocognitive performance was summarized by global T -scores. Associations of global T -scores with anemia and erythrocyte indices were determined in univariable analyses. To examine the influence of hepcidin on the relationship between neurocognitive performance and erythrocyte indices, we evaluated interactions between these covariates in relation to global T -scores and then performed stratified analyses.

RESULTS

In multivariable analyses, hepcidin detectability interacted with age ( P  = 0.007) and mean corpuscular volume (MCV; P  = 0.031) in relation to the global T -score. Interactions between anemia and erythrocyte indices on global T -scores were significant (anemia × MCV, P  = 0.008; anemia × MCH, P  = 0.011). Stratified analyses identified that lower global T -scores were associated with older age ( P  = 0.001) and higher MCV ( P  = 0.0046) and mean corpuscular hemoglobin (MCH, P  = 0.026) only when hepcidin was undetectable. Among the anemic, worse global T -score was associated with higher MCV ( P  = 0.001) and MCH ( P  = 0.002).

CONCLUSION

Findings suggest that iron-related factors (hepcidin, anemia, MCV, MCH) and age influence neurocognitive health. This cross-sectional study underscores hepcidin as an effect modifier in the associations of erythrocyte indices, anemia, and age with neurocognitive function in PWH.

Platelet Extracellular Vesicles as Natural Delivery Vehicles for Mitochondrial Dysfunction Therapy?

Mitochondria are vital for energy production, metabolic regulation, and cellular signaling. Their dysfunction is strongly implicated in neurological, cardiovascular, and muscular degenerative diseases, where energy deficits and oxidative stress accelerate disease progression. Platelet extracellular vesicles (PEVs), once called "platelet dust", have emerged as promising agents for mitigating mitochondrial dysfunction. Like other extracellular vesicles (EVs), PEVs carry diverse molecular cargo and surface markers implicated in disease processes and therapeutic efficacy. Notably, they may possibly contain intact or partially functional mitochondrial components, making them tentatively attractive for targeting mitochondrial damage. Although direct research on PEVs-mediated mitochondrial rescue remains limited, current evidence suggests that PEVs can modulate diseases associated with mitochondrial dysfunction and potentially enhance mitochondrial health. This review explores the therapeutic potential of PEVs in neurodegenerative and cardiovascular disorders, highlighting their role in restoring mitochondrial health. By examining recent advancements in PEVs research, we aim to shed light on novel strategies for utilizing PEVs as therapeutic agents. Our goal is to underscore the importance of further fundamental and applied research into PEVs-based interventions, as innovative tools for combating a wide range of diseases linked to mitochondrial dysfunction.

Photobiomodulation by LED 660 nm and Taurine against H2O2 oxidative stress in SH-SY5Y cells

Alzheimer's Disease (AD) is a progressive uncurable neurodegenerative pathology affecting millions worldwide. Photobiomodulation and Taurine are promising alternatives for preventing and reducing the rapid progression of neurodegeneration, stimulating the reconstructing of neural tissue structures, especially improving mitochondrial activity, which is highly impaired in AD. In this study, the mitochondrial effects of Taurine combined with light emitting diode (LED) irradiation were evaluated on human neuroblastoma cells (SH-SY5Y), under oxidative stress condition by hydrogen peroxide (H2O2) exposure, a considerable modulator in AD. We evaluated LED irradiation at the wavelength of 660 nm and Taurine under different concentrations before and together with exposing SH-SY5Y cells to different concentrations of H2O2, assessing mitochondrial activity by the MTT colorimetric test and labeling live cells mitochondria by the fluorescent probe MitoTracker. Cell viability was also evaluated by the trypan blue exclusion assay, and cellular morphological structures were imaged by scanning electron microscopy (SEM). Neuroprotective effects were achieved by both LED irradiation and LED irradiation + Taurine when cells were exposed to them before H2O2-induced stress. Comparing both agents, LED irradiation at 660 nm is sufficient to improve mitochondrial activity, however, healthy mitochondrial morphology was only observed when cells were treated with Taurine together with LED irradiation, representing affordable candidates that act in synergy against oxidative stress, one of the main contributors to neurodegeneration.

Antioxidant Potential of Selected Apiaceae Plant Extracts: A Study Focused on the Chemical Composition and Neuroprotective Effect of Coriandrum sativum L. Extract Against Lead (Pb)-Induced Neurotoxicity in Rats

Lead is a common environmental pollutant. It can affect several body systems including the central nervous system (CNS). Lead can disrupt the nervous system by different mechanisms including oxidative stress, inflammation, disruption of neurotransmission, and aberrant autophagy. Apiaceous species have been used traditionally as food flavoring and medicine, representing a rich source of bioactive compounds. In the current study, the antioxidant power of four Apiaceous extracts (Foeniculum vulgare L., Pimpinella anisum L., Coriandrum sativum L., and Cuminum cyminum L.) was evaluated. Additionally, the metabolite profiles of the selected species were comprehensively investigated by untargeted liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) coupled to chemometry. Coriander (Coriandrum sativum L.) extract showed the highest radical scavenging activity and reducing power. Coriander was further subjected to in vivo evaluation of its protective effect against Lead (Pb)-induced neurotoxicity. Administration of coriander extracts improved the short- and long-term memory performance and decreased hippocampal Pb content in Pb-intoxicated rats. Moreover, it attenuated hippocampal oxidative stress, neurochemical changes, and exhibited anti-inflammatory effect in the hippocampal tissue. Further, coriander extracts attenuated Pb inhibitory effect on the mammalian target of Rapamycin (mTORC1) pathway resulting in upregulation of Phospho-p70 S6 Kinase (P-P70S6K) and Phospho-S6 Ribosomal Protein (PS6) and downregulation of Beclin-1. Additionally, some selected coriander ingredients were subjected to molecular docking to examine their regulatory effect on mTORC-1 and IκB kinase complex (Ikk-β). The present findings highlight the future pharmaceutical utilization of coriander extract as valuable source of phenolic compounds that can be used as antioxidant, anti-inflammatory, and neuroprotective agents against Pb-induced neurotoxicity.

Regulation and mechanism of Bletilla striata polysaccharide on delaying aging in Drosophila melanogaster

Bletilla striata polysaccharide (BSP) is a natural bioactive compound known for its promising health benefits, including antioxidant, immunomodulatory, and anti-inflammatory effects. However, its potential in combating aging remains largely unexplored. This study aims to investigate the anti-aging effects of BSP in the Drosophila melanogaster model. The results show that BSP supplementation significantly extends the lifespan of flies in a concentration-dependent manner, with the most pronounced effects observed at a concentration of 3 mg/mL. Lifespan extension is associated with enhanced antioxidative capacities, as evidenced by increased SOD and CAT activities, and decreased MDA content. Additionally, BSP ameliorates age-related symptoms, including improved climbing ability and enhanced intestinal barrier function. Furthermore, BSP supplementation enhances resistance to H2O2-induced oxidative and starvation stresses, attenuates the lead (Pb)-induced toxicity, and delays the onset of Alzheimer's phenotypes in flies. RNA-Seq analysis reveals that BSP supplementation leads to the differential expression of 992 genes. KEGG pathway analysis highlights significant changes in metabolic pathways, including galactose metabolism, starch and sucrose metabolism, and carbon metabolism. Key genes such as Mal-A1, Amy-d, Men-b, Pgm-1, Mdh1, and Hex-C are downregulated, while CG32026, CG11291, and Ald2 are upregulated. These findings suggest BSP exhibits significant anti-aging and protective properties, making it a potential therapeutic agent.

Advanced Glycation End Products in Disease Development and Potential Interventions

Advanced glycation end products (AGEs) are a group of compounds formed through non-enzymatic reactions between reducing sugars and proteins, lipids, or nucleic acids. AGEs can be generated in the body or introduced through dietary sources and smoking. Recent clinical and animal studies have highlighted the significant role of AGEs in various health conditions. These compounds accumulate in nearly all mammalian tissues and are associated with a range of diseases, including diabetes and its complications, cardiovascular disease, and neurodegeneration. This review summarizes the major diseases linked to AGE accumulation, presenting both clinical and experimental evidence. The pathologies induced by AGEs share common mechanisms across different organs, primarily involving oxidative stress, chronic inflammation, and direct protein cross-linking. Interventions targeting AGE-related diseases focus on inhibiting AGE formation using synthetic or natural antioxidants, as well as reducing dietary AGE intake through lifestyle modifications. AGEs are recognized as significant risk factors that impact health and accelerate aging, particularly in individuals with hyperglycemia. Monitoring AGE level and implementing nutritional interventions can help maintain overall health and reduce the risk of AGE-related complications.

Xanthine Oxidoreductase: A Double-Edged Sword in Neurological Diseases

Non-communicable neurological disorders are the second leading cause of death, and their burden continues to increase as the world population grows and ages. Oxidative stress and inflammation are crucially implicated in the triggering and progression of multiple sclerosis, Alzheimer's disease, amyotrophic lateral sclerosis, Huntington's disease, Parkinson's disease, and even stroke. In this narrative review, we examine the role of xanthine oxidoreductase (XOR) activities and products in all the above-cited neurological diseases. The redox imbalance responsible for oxidative stress could arise from excess reactive oxygen and nitrogen species resulting from the activities of XOR, as well as from the deficiency of its main product, uric acid (UA), which is the pivotal antioxidant system in the blood. In fact, with the exception of stroke, serum UA levels are inversely related to the onset and progression of these neurological disorders. The inverse correlation observed between the level of uricemia and the presence of neurological diseases suggests a neuroprotective role for UA. Oxidative stress and inflammation are also caused by ischemia and reperfusion, a condition in which XOR action has been recognized as a contributing factor to tissue damage. The findings reported in this review could be useful for addressing clinical decision-making and treatment optimization.

Shapeshifter W-Tau Peptide Inhibits Tau Aggregation and Disintegrates Paired Helical Filaments

Tauopathies comprise a range of neurodegenerative conditions characterized by the aberrant accumulation of tau protein clumps in the brain. These aggregates are formed by different tau splicing isoforms. Here, we analyzed the role of a specific intron-derived peptide called the W-Tau peptide on the polymerization-depolymerization of tau filaments. This peptide originates from a new isoform of the tau protein, named W-Tau, which is formed due to the retention of intron 12. AlphaFold3 (AF3)-based in silico investigations suggested that the W-Tau peptide interacts with tau monomers. Our in vitro experiments confirmed these predictions and showed that the W-Tau peptide inhibited tau aggregation. In addition, the W-Tau peptide disrupted preexisting paired helical filaments (PHFs) isolated from postmortem brain samples of patients with Alzheimer's disease, thereby supporting its potential therapeutic value. The effectiveness of the W-Tau peptide was demonstrated by the decrease in tau aggregation observed after cotransfection of the W-Tau peptide and PHF seeds, as demonstrated by analysis involving a fluorescence resonance energy transfer (FRET) cell biosensor. The W-Tau peptide breaks PHFs by selectively attaching to their ends, causing the structures to unwind and convert into circle-like formations. Considering the potential neuroprotective effects against tauopathies, the W-Tau isoform and its peptide are interesting candidates for future therapeutic interventions.

Alzheimer's disease and insomnia: a bibliometric study and visualization analysis

Background

Alzheimer's disease (AD) is the fastest-growing neurodegenerative disorder globally, with patient numbers expected to rise to 130 million by 2050. Insomnia, a prevalent comorbidity, exhibits a bidirectional relationship with AD: insomnia accelerates AD pathology, while AD worsens sleep disorders. This relationship has emerged as a key area of research. Current mechanisms involve oxidative stress, inflammatory responses, and glymphatic system dysfunction, yet a comprehensive review of these processes remains absent.

Objective

To conduct a visual analysis of the relationship between Alzheimer's disease and insomnia using CiteSpace.

Methods

Literature on "insomnia" and "Alzheimer's disease" published between January 1, 2000, and October 31, 2024, was retrieved from the Web of Science Core Collection. CiteSpace and VOSviewer software were used to analyze institutions, authors, and keywords.

Results

A total of 1,907 articles were analyzed, revealing a consistent upward trend in publication volume. The United States and the Mayo Clinic were identified as leading contributors, producing 704 and 57 publications, respectively. Boeve Bradley F the most prolific author contributed 30 publications. Collaboration was actively observed among countries, institutions, and authors. High-frequency keywords identified were "Parkinson's disease," "cognitive impairment," and "sleep behavior disorder." Emerging research areas are likely to focus on "sleep quality" and the "glymphatic system."

Conclusion

This study is the first to apply bibliometric analysis to identify three key trends in AD and insomnia research: the dominance of the United States and Mayo Clinic, strong international collaboration, and a focus on critical areas such as cognitive impairment, the glymphatic system, and sleep interventions. Insomnia may accelerate AD progression via multiple pathways, indicating that enhancing sleep quality could provide new strategies for early intervention. Future research should prioritize advancing the clinical translation of sleep interventions and investigating the mechanisms of the glymphatic system.

Altered tear fluid protein expression in persons with mild Alzheimer's disease in proteins involved in oxidative stress, protein synthesis, and energy metabolism

BackgroundTear fluid (TF) is a protein-rich solution that reflects pathophysiological changes in Alzheimer's disease (AD).ObjectiveIn this study, we examined whether TF proteins were differently expressed in persons with mild AD dementia compared to cognitively healthy controls (CO).MethodsWe analyzed data from 53 study participants including 34 CO (mean age, 71 years; Mini-Mental State Examination [MMSE] score, 28.9 ± 1.4), and 19 patients with AD (Clinical Dementia Rating, 0.5-1; mean age, 72 years; MMSE score, 23.8 ± 2.8). All participants underwent cognitive testing, as well as neurological and ophthalmological examinations. TF was collected using Schirmer strips, and TF protein content was evaluated using mass spectrometry-based proteomics and label-free quantification.ResultsWe found that 16 proteins exhibited significantly upregulated expression in the AD group compared to the CO group (p ≤ 0.05). These proteins were NP1L4, BBOX1, CYTC, RNAS4, PCD, RNT2, AL1A3, SYSC, TPIS, CLH1, PGAM1, EIF3L, 5NTC, HNRNPA2B1, PYGL, and ERO1α. No proteins were significantly downregulated in the AD group compared to the CO group.ConclusionsOur results support the hypothesis that TF is a potential source of biomarkers for AD. Part of those proteins with altered expression have previously linked to increased oxidative stress, changed protein synthesis, and disturbed regulation of energy metabolism related to AD or neurodegenerative disease. The present results indicate the value of continued investigation of TF proteins in AD.

Reactive Oxygen Species as a Common Pathological Link Between Alcohol Use Disorder and Alzheimer's Disease with Therapeutic Implications

Chronic alcohol consumption leads to excessive production of reactive oxygen species (ROS), driving oxidative stress that contributes to both alcohol use disorder (AUD) and Alzheimer's disease (AD). This review explores how ROS-mediated mitochondrial dysfunction and neuroinflammation serve as shared pathological mechanisms linking these conditions. We highlight the role of alcohol-induced oxidative damage in exacerbating neurodegeneration and compare ROS-related pathways in AUD and AD. Finally, we discuss emerging therapeutic strategies, including mitochondrial antioxidants and inflammasome inhibitors, that target oxidative stress to mitigate neurodegeneration. Understanding these overlapping mechanisms may provide new insights for preventing and treating ROS-driven neurodegenerative disorders.

Influence of Ibuprofen on glycerophospholipids and sphingolipids in context of Alzheimer´s Disease

Alzheimer's disease (AD) is a multifactorial disorder associated with neuroinflammation, elevated oxidative stress, lipid alterations as well as amyloid-deposits and the formation of neurofibrillary tangles. Ibuprofen, a globally used analgesic, is discussed to influence disease progression due to its anti-inflammatory effect. However, changes in lipid-homeostasis induced by Ibuprofen have not yet been analyzed. Here we investigate the effect of Ibuprofen on lipid classes known to be associated with AD. Ibuprofen treatment leads to a significant increase in phosphatidylcholine, sphingomyelin and triacylglyceride (TAG) species whereas plasmalogens, which are highly susceptible for oxidation, were significantly decreased. The observed alterations in phosphatidylcholine and sphingomyelin levels in presence of Ibuprofen might counteract the reduced phosphatidylcholine- and sphingomyelin-levels found in AD brain tissue with potential positive aspects on synaptic plasticity and ceramide-induced apoptotic effects. On the other hand, Ibuprofen leads to elevated TAG-level resulting in the formation of lipid droplets which are associated with neuroinflammation. Reduction of plasmalogen-levels might accelerate decreased plasmalogen-levels found in AD brains. Treatment of Ibuprofen in terms of lipid-homeostasis reveals both potentially positive and negative changes relevant to AD. Therefore, understanding the influence of Ibuprofen on lipid-homeostasis may help to understand the heterogeneous results of studies treating AD with Ibuprofen.

Sulfonic acid functionalized β-amyloid peptide aggregation inhibitors and antioxidant agents for the treatment of Alzheimer's disease: Combining machine learning, computational, in vitro and in vivo approaches

Alzheimer's disease (AD) is characterized as a neurodegenerative disorder that is caused by plaque formation by accumulating β-amyloid (Aβ), leading to neurocognitive function and impaired mental development. Thus, targeting Aβ represents a promising target for the development of therapeutics in AD management. Several functionalized sulfonic acid molecules have been reported, including tramiprosate prodrug, which is currently in clinical trial III and exhibits a good response in mild to moderate AD patients. Therefore, expanding upon this approach, we hypothesized that the sulfonic acid functionalized aromatic class molecule might demonstrate a good inhibitory effect against β-amyloid aggregation, leading to a decrease in the progression burden of AD. We used computational and in vitro approaches to establish effective compounds. As a result, three potent hit molecules were selected based on binding score as well as availability. In the case of safety profile of compounds, in vitro using human neuroblastoma SH-SY5Y cells and in vivo using C. elegans was performed at doses up to 500 μM; no difference in viability was exhibited between control and treatment groups. However, H2O2-induced ROS stress was significantly reduced in neuroblastoma cells after treatment. The AFM and ThT-embedded β-amyloid1-42 kinetic studies confirmed B-PEA-MBSA and H-HPA-NSA potency. H-HPA-NSA arrested elongation phase of Aβ aggregation in kinetic study at a lower concentration (10 μM), while B-PEA-MBSA reduced the intensity of stationary phase at a dose of 100 μM. Thus, based on the outcomes, it can be suggested that B-PEA-MBSA and H-HPA-NSA can prevent β-amyloid aggregation with mild to moderate AD.

IL-17 A Exacerbated Neuroinflammatory and Neurodegenerative Biomarkers in Intranasal Amyloid-Beta Model of Alzheimer's Disease

Proinflammatory cytokines, especially interleukin-17 A (IL-17 A) have been found to be significantly associated with AD patients. IL-17 A amplifies neuroinflammation during AD pathology. This study highlighted the ability of IL-17 A to exacerbate amyloid-beta-induced pathology in animals. The AD pathology was induced with repeated intranasal administration of Aβ along with recombinant mouse IL-17 A (rmIL-17) at 1, 2 and 4 µg/kg for seven alternate days. Although, the combination of rmIL-17 and Aβ did not have severe effects on memory of the animals, but it drastically increased the IL-17 A mediated signaling, level of proinflammatory cytokines, oxidative stress and reduced antioxidants in the hippocampus and cortex regions of the animal brains. Interestingly, combining rmIL-17 with Aβ also triggered the expression of AD structural markers like pTau, amyloid-beta and BACE1 in the brain regions. Furthermore, rmIL-17 with Aβ exposure stimulated astrocytes and microglia leading to activation of proinflammatory signaling in the brain of the animals. These results showed the propensity of IL-17 A to promote severity of AD pathology and suggest IL-17 A as potent therapeutic target to control AD progression.

Mechanistic Insights into the Neuroprotective Potential of Aegle marmelos (L.) Correa Fruits against Aβ-Induced Cell Toxicity in Human Neuroblastoma SH-SY5Y Cells

Background/Objectives: Amyloid-β (Aβ) plaque accumulation, oxidative stress, and cholinergic dysfunction are hallmarks of Alzheimer's disease (AD), a neurodegenerative disability that progresses over time, ultimately resulting in the loss of neurons. The side effects and limitations of current synthetic drugs have shifted attention toward natural alternatives. This study investigates the ethanolic extract of Aegle marmelos (L.) Corrêa fruits for their antioxidant, AChE-inhibitory, and anti-amyloidogenic properties, as well as their neuroprotective effects against amyloid beta-peptide (Aβ1-42). Methods: Phytochemical constituents were identified through HR-LCMS analysis and their antioxidant (DPPH, FRAP) and neuroprotective activities (AChE inhibition, ThT binding, MTT assay, ROS reduction, MMP restoration, and AD-related gene expression via qRT-PCR) were assessed using SHSY-5Y neuroblastoma cells. Results: The extract revealed the existence of flavonoids, phenols, and other bioactive substances. In vitro assays demonstrated strong antioxidant and AChE-inhibitory activities, while the ThT binding assay showed protection against amyloid-β aggregation. The extract exhibited no cytotoxicity in SHSY-5Y cells, even at a concentration of 500 μg/mL, whereas Aβ1-42 at 20 μM induced significant cytotoxicity. Co-treatment with Aβ1-42 (10 μM and 20 μM) and the extract improved cell viability (˃50%) and reduced ROS levels. Additionally, the extract restored mitochondrial membrane potential in Aβ1-42 treated cells, highlighting its role in preserving mitochondrial function. Conclusions: These findings suggest that A. marmelos fruits serve as a powerful source of natural antioxidants, AChE inhibitors, and anti-amyloidogenic agents, positioning them as a compelling option for AD treatment.

Transcriptome analysis reveals the mechanism of Rhodiola polysaccharide affecting the proliferation of porcine Leydig cells under hypoxia

Hypoxia can affect the function of the male reproductive system and reduce fertility. Rhodiola polysaccharide (RDP) is the active ingredient of Rhodiola rosea L. and has a positive effect on reproductive cells. However, the mechanism of the effect of RDP on the proliferation of cells under hypoxia is still unclear. The experiment selected porcine Leydig cells (PLCs) as the test object and divided them into three groups: normal group, hypoxia group, and hypoxia + RDP-treated group. Cell viability was detected using CCK8 assay. RNA-Seq technology was used to identify the key genes that influence the effect of RDP on PLCs under hypoxia conditions and to determine their regulatory pathways. Transcriptome sequencing of PLCs from the N and H groups identified 6,794 differentially expressed genes (DEGs), including 3,329 up-regulated genes and 3,465 down-regulated genes. These DEGs were significantly enriched in the cell cycle signaling pathway, indicating that hypoxia mainly affects the cell cycle and inhibits cell proliferation. Furthermore, comparison of the transcriptomes between the H and HR group revealed 285 DEGs, including 137 up-regulated and 148 down-regulated, most of DEGs were found to be enriched in oxidative phosphorylation pathways. RDP inhibits PLCs apoptosis and promotes cell proliferation by up-regulating the expression of CXCL2, JUNB and VCAM1 of the TNF signaling pathway, and VEGFA, SGK2 and SPP1 of the PI3K/AKT signaling pathway. These genes deserve further study as candidate for understanding the role of RDP in alleviating the hypoxia stress.

Compensatory enhancement of orexinergic system functionality induced by amyloid-β protein: a neuroprotective response in Alzheimer's disease

Background

Amyloid-β protein (Aβ) accumulation is a defining characteristic of Alzheimer's disease (AD), resulting in neurodegeneration and a decline in cognitive function. Given orexin's well-documented role in enhancing memory and cognition, this study investigates its potential to regulate Aβ-induced neurotoxicity, offering new perspectives into AD management.

Methods

This paper simulated Aβ accumulation in the hippocampus of AD patients by administering Aβ1-42 oligomers into the bilateral hippocampal dentate gyrus of ICR mice. Inflammatory cytokines (IL-6, TNF-α) and orexin-A levels were measured by ELISA. Additionally, the excitability of orexinergic neurons was assessed by IHC targeting c-Fos expression. These methodologies evaluated the Aβ-induced neuroinflammation, orexinergic system functionality, and dexamethasone's (Dex) effects on these processes.

Results

Injection of Aβ1-42 oligomer resulted in elevated levels of IL-6, TNF-α, and orexin-A in the hippocampus, as well as increased excitability of orexinergic neurons in the lateral hypothalamus (LH). Dex treatment reduced neuroinflammation, causing a reduction in orexin-A levels and the excitability of orexinergic neurons.

Conclusion

Aβ-induced neuroinflammation is accompanied by enhanced levels of orexin-A and orexinergic neuron excitability. These findings suggest that the enhanced functionality of the orexinergic system may become a compensatory neuroprotective mechanism to counteract neuroinflammation and enhance cognitive function.

Unveiling the role of Na⁺/K⁺-ATPase pump: neurodegenerative mechanisms and therapeutic horizons

Sodium and potassium-activated adenosine 5'-triphosphatase (Na+/K+-ATPase) is a pivotal plasma membrane enzyme involved in neuronal activity and cellular homeostasis. The dysregulation of these enzymes has been implicated in a spectrum of neurodegenerative disorders like Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and neurodevelopmental disorders including autism spectrum disorder (ASD), psychiatric disorders such as schizophrenia, and neurological problems like epilepsy. A hallmark of these disorders is the gradual loss of neuronal integrity and function, often exacerbated by protein accumulation within brain cells. This review delves into the multifaceted role of Na+/K+-ATPase dysfunction in driving oxidative stress, excitotoxicity, and neuroinflammation, contributing to synaptic and neuronal damage. Emerging therapeutic strategies, such as gene therapy and developing isoform-specific enzyme modulators, offer promising avenues for targeted interventions. Furthermore, this review highlights innovative research directions, including the role of Na⁺/K⁺-ATPase in synaptic plasticity, the identification of endogenous regulators, and its contribution to neuroinflammatory pathways. Personalized medicine and advanced gene-editing technologies are positioned as transformative tools for crafting safer and more precise therapies tailored to individual patients. This comprehensive exploration underscores the enzyme's therapeutic potential and sets the stage for developing novel targeted strategies to mitigate the burden of Na⁺/K⁺-ATPase-linked neurological disorders.

Therapeutic assessment of a novel mitochondrial complex I inhibitor in in vitro and in vivo models of Alzheimer's disease

Despite recent approval of monoclonal antibodies that reduce amyloid (Aβ) accumulation, the development of disease-modifying strategies targeting the underlying mechanisms of Alzheimer's disease (AD) is urgently needed. We demonstrate that mitochondrial complex I (mtCI) represents a druggable target, where its weak inhibition activates neuroprotective signaling, benefiting AD mouse models with Aβ and p-Tau pathologies. Rational design and structure-activity relationship studies yielded novel mtCI inhibitors profiled in a drug discovery funnel designed to address their safety, selectivity, and efficacy. The new lead compound C458 is highly protective against Aβ toxicity, has favorable pharmacokinetics, and has minimal off-target effects. C458 exhibited excellent brain penetrance, activating neuroprotective pathways with a single dose. Preclinical studies in APP/PS1 mice were conducted via functional tests, metabolic assessment, in vivo 31P-NMR spectroscopy, blood cytokine panels, ex vivo electrophysiology, and Western blotting. Chronic oral administration improved long-term potentiation, reduced oxidative stress and inflammation, and enhanced mitochondrial biogenesis, antioxidant signaling, and cellular energetics. These studies provide further evidence that the restoration of mitochondrial function and brain energetics in response to mild energetic stress represents a promising disease-modifying strategy for AD.

Impact of diet and exercise on mitochondrial quality and mitophagy in Alzheimer's disease

Alzheimer's disease (AD) is a devastating neurodegenerative disorder that affects millions of people worldwide. It is characterized by the accumulation of beta-amyloid and phosphorylated tau, synaptic damage, and mitochondrial abnormalities in the brain, leading to the progressive loss of cognitive function and memory. In AD, emerging research suggests that lifestyle factors such as a healthy diet and regular exercise may play a significant role in delaying the onset and progression of the disease. Mitochondria are often referred to as the powerhouse of the cell, as they are responsible for producing the energy to cells, including neurons to maintain cognitive function. Our article elaborates on how mitochondrial quality and function decline with age and AD, leading to an increase in oxidative stress and a decrease in ATP production. Decline in mitochondrial quality can impair cellular functions contributing to the development and progression of disease with the loss of neuronal functions in AD. This article also covered mitophagy, the process by which damaged or dysfunctional mitochondria are selectively removed from the cell to maintain cellular homeostasis. Impaired mitophagy has been implicated in the progression and pathogenesis of AD. We also discussed the impact of impaired mitophagy implicated in AD, as the accumulation of damaged mitochondria can lead to increased oxidative stress. We expounded how dietary interventions and exercise can help to improve mitochondrial quality, and mitochondrial function and enhance mitophagy in AD. A diet rich in antioxidants, polyphenols, and mitochondria-targeted small molecules has been shown to enhance mitochondrial function and protect against oxidative stress, particularly in neurons with aged and mild cognitively impaired subjects and AD patients. Promoting a healthy lifestyle, mainly balanced diet and regular exercise that support mitochondrial health, in an individual can potentially delay the onset and progression of AD. In conclusion, a healthy diet and regular exercise play a crucial role in maintaining mitochondrial quality and mitochondrial function, in turn, enhancing mitophagy and synaptic activities that delay AD in the elderly populations.

The Potential Role of Neurogranin in Alzheimer's Disease

Alzheimer's disease (AD) is the most common form of dementia and is characterized by the excessive deposition of amyloid-β (Aβ) plaques and the formation of neurofibrillary tangles. Numerous new studies also indicate that synaptic damage and loss play crucial roles in AD and form the basis of cognitive impairment. In recent years, synaptic-related proteins have emerged as important biomarkers for the early diagnosis of AD. Among these proteins, neurogranin (Ng), a postsynaptic protein widely present in the dendritic spines of the associative cortex in the brain, plays a significant role in memory, learning, synaptic plasticity, and long-term potentiation (LTP). This review aims to reveal the link between Ng and AD, as well as the potential for the diagnosis of AD, the prediction of the development of the disease, and the identification of a therapeutic target for AD.

Human serum albumin-3-amino-1-propanesulfonic acid conjugate inhibits amyloid-β aggregation and mitigates cognitive decline in Alzheimer's disease

Alzheimer's disease (AD) is the most commonly occurring brain disorder, characterized by the accumulation of amyloid-β (Aβ) and tau, subsequently leading to neurocognitive decline. 3-Amino-1-propanesulfonic acid (TPS) and its prodrug, currently under clinical trial III, serve as promising therapeutic agents targeting Aβ pathology by specifically preventing monomer-to-oligomer formation. Inspired by the potency of TPS prodrug, we hypothesized that conjugating TPS with human serum albumin (HSA) could enhance brain delivery and synergistically inhibit Aβ aggregation in mild to moderate AD. Thus, we prepared and extensively characterized HSA-TPS (h-TPS) conjugate using an eco-friendly coupling method. In vitro studies on Aβ aggregation kinetics and AFM imaging revealed significant prevention of Aβ aggregation. Additionally, h-TPS significantly reduced Aβ-induced neurotoxicity and H2O2-mediated reactive oxygen species (ROS) stress in SH-SY5Y cells. Moreover, h-TPS administration improved blood-brain barrier permeability and cellular uptake into neuronal cells as well as showed in vivo uptake inside the brain within 1 h. In vivo studies using an Aβ1-42-induced acute AD rat model exhibited a dose-dependent significant reduction in hippocampal Aβ levels and restoration of declined spatial learning and memory with h-TPS treatment. Overall, findings suggest that h-TPS conjugate might be a promising neuroprotective agent for preventing Aβ aggregation in mild to moderate AD.

Astaxanthin nanoemulsion improves cognitive function and synaptic integrity in Streptozotocin-induced Alzheimer's disease model

Astaxanthin derived from natural sources has excellent antioxidant and anti-inflammatory effects, and it is currently being widely researched as a neuroprotectant. However, astaxanthin possesses low oral bioavailability, and thus, astaxanthin extract from Haematococcus pluvialis was formulated into a nanoemulsion to improve its bioavailability and administered to Alzheimer's disease (AD)-like rats to study its possible neuroprotective benefits. Astaxanthin nanoemulsion was administered orally once a day for 28 days to streptozotocin (STZ)-induced AD rats at concentrations of 160, 320, and 640 mg/kg of body weight (bw) and subsequently assessed for cognitive function using behavioral assessments. Brain samples were collected for the assessment of AD biomarkers. Astaxanthin nanoemulsion at a dosage of 640 mg/kg bw significantly improved spatial learning, spatial memory, and recognition memory against STZ-AD rats. At 320 and 640 mg/kg bw, astaxanthin nanoemulsion significantly reduced levels of hippocampus synaptosomal amyloid beta and paired-helical fibrillary tau protein while increasing neuron survival. Additionally, astaxanthin nanoemulsion at 640 mg/kg bw significantly increased acetylcholine levels in the hippocampus and cerebellum. Astaxanthin nanoemulsion at all treatment dosages significantly reduced malondialdehyde, a lipid peroxidation product, and neuroinflammatory mediators (GFAP and TNF-α). Astaxanthin nanoemulsion supplementation has the potential to improve cognitive function and synaptic function by lowering amyloid beta and tau levels, as well as preserve neuron integrity by reducing neuroinflammation and lipid peroxidation, indicating that it may be able to treat some of the underlying causes of AD.

Development of novel melatonin-isatin hybrids as multifunctional agents for Alzheimer's disease

The development of multifunctional agents has been a heated area of research for AD treatment in recent years. In this work, a series of melatonin-isatin hybrids were designed, synthesized, and evaluated as multifunctional agents for treating AD. In vitro studies indicated that most of the synthesized compounds displayed moderate to good MAO-B inhibition activities and good antioxidant activities. In particular, compounds IM-5 and IM-10 exhibited the best inhibitory activities with IC50 value of 12.4 μM and 15.6 μM against MAO-B, and potent antioxidant activities with their ORAC-FL values of 4.6 and 5.2 at 5 μM, respectively. ThT assay revealed compounds IM-5 and IM-10 exhibited the optimal Aβ1-42 self-induced aggregation inhibitory activities with the inhibition ratio of 72.8% and 69.7% at 20 μM. In addition, compounds IM-5 and IM-10 exhibited low cytotoxicities and significant neuroprotective effects on Aβ1-42-induced and H2O2-induced SH-SY5Y cell injury. More importantly, compounds IM-5 and IM-10 could significantly ameliorate the memory impairment and cognition injury in scopolamine-induced mice. The SwissADME program was used to predict drug-like properties of compounds IM-5 and IM-10 which exhibited they had good pharmacokinetics and drug-likeness properties. Molecular docking study further manifested that compounds IM-5 and IM-10 showed high hMAO-B inhibitory potency. In summary, all above results revealed compounds IM-5 and IM-10 might be promising multifunctional agents for AD treatment.

Rosa Roxburghii Tratt Polysaccharides Prevent Alzheimer's Disease-Like Cognitive Dysfunctions and Pathology in Rats by Regulating the Microbiota-Gut-Brain Axis and Oxidative Stress

The microbial-gut-brain axis and oxidative stress may be important to the pathogenesis of Alzheimer's disease (AD). Rosa roxburghii Tratt polysaccharides (RRTP) have a strong antioxidant effect and can affect the gut microbiota, and whether it can affect AD is unknown. So, AlCl3 and d-galactose were used to establish AD model rats, and RRTP was used as an intervention treatment. Morris water maze test was used to detect cognitive functions. The hippocampus was used to observe the pathological changes, and the cortex was used to measure antioxidant markers. The stool was collected for 16S rDNA sequencing. Morris water maze test showed that the learning ability and memory level of AD group rats were decreased, and RRTP intervention could mitigate the injury to a certain extent. In the AD group, hematoxylin-eosin staining revealed changes in the morphology of neurons, silver glycine staining revealed neurofibrillary tangles and Congo red staining revealed β-amyloid. RRTP could ameliorate the above changes to some extent. The results of superoxide dismutase, malondialdehyde, and glutathione peroxidase showed that the antioxidant capacity in the RRTP intervention group was significantly higher than that in the AD group. 16S rDNA sequencing results showed that there were differences in the species composition of gut microbiota, and the ratio of Firmicutes to Bacteroidetes in the AD group was decreased. After RRTP intervention, the proportion of Lactobacillus increased. In conclusion, RRTP may prevent AD pathology and cognitive functions in rats to a certain extent through the microbiota-gut-brain axis and oxidative stress.

Tau association with synaptic mitochondria coincides with energetic dysfunction and excitatory synapse loss in the P301S tauopathy mouse model

Neurodegenerative Tauopathies are a part of several neurological disorders and aging-related diseases including, but not limited to, Alzheimer's Disease, Frontotemporal Dementia with Parkinsonism, and Chronic Traumatic Encephalopathy. The major hallmarks present in these conditions include Tau pathology (composed of hyperphosphorylated Tau tangles) and synaptic loss. in vivo studies linking Tau pathology and mitochondrial alterations at the synapse, an avenue that could lead to synaptic loss, remain predominantly scarce. For this reason, using 3-month-old wild-type and human mutant Tau P301S transgenic mice, we investigated the association of Tau with mitochondria, synaptosome bioenergetics, and characterized excitatory synaptic loss across hippocampal regions (Dentate Gyrus, perisomatic CA3, and perisomatic CA1) and in the parietal cortex. We found a significant loss of excitatory synapses in the parietal cortex and hippocampal Dentate Gyrus (DG) of Tau P301S mice. Furthermore, we found that Tau (total and disease-relevant phosphorylated Tau) associates with both the non-synaptic and synaptic mitochondria of Tau P301S mice and this coincided with synaptic mitochondrial dysfunction. The findings presented here suggest that Tau associates with mitochondria at the synapse, leading to synaptic mitochondrial dysfunction, and likely contributing to synaptic loss.

Usnic Acid Derivatives as Multi-Target Anti-Alzheimer's Disease Agents: Design, Synthesis, X-Ray Single Crystal Structure of Zn(II) Complex and Biological Activities

Alzheimer's disease (AD) is multifactorial, which makes the design of multi-target-directed ligands an attractive strategy for the development of anti-AD drugs. In order to enhance the anti-AD effects and reduce the toxicity, two usnic acid (UA) derivatives (1-2) were designed, synthesized and fully characterized by introducing dimethylamine Schiff base moiety into the toxic "triketone" portion. Ellman's method and molecular docking were used to test the cholinesterase inhibitory activities. Antioxidant activities were studied with Fenton reaction, cyclic voltammetry and C. elegans. The results showed that compared with UA, 1-2 had stronger anti-cholinesterase activities and similar antioxidant activities. Notably, solvent evaporation of 2 and ZnCl2 formed a single crystal, which was revealed to be a Zn(II) complex with UA and tertiary amine as mixed ligands by X-ray diffraction. The hydrolysis of 2 was thus furtherly studied by HPLC. Furthermore, the crystal structure supported the replacement of toxic "triketone" moiety in the chelation process, playing a detoxifying role and at the same time regulating metal homeostasis. In silico prediction also showed low hepatotoxicity and acceptable drug-likeness of 1-2. Overall, this work provided useful insights into multi-target anti-AD candidates with the natural product UA as the lead compound.

Exploratory analysis of the proteomic profile in plasma in adults with Down syndrome in the context of Alzheimer's disease

INTRODUCTION

Adults with Down syndrome (DS) show increased risk for Alzheimer's disease (AD) due to the triplication of chromosome 21 encoding the amyloid precursor protein gene. Further, this triplication possibly contributes to dysregulation of the immune system, furthering AD pathophysiology.

METHODS

Using Olink Explore 3072, we measured ∼3000 proteins in plasma from 73 adults with DS and 15 euploid, healthy controls (HC). Analyses for differentially expressed proteins (DEP) were carried out, and pathway and protein network enrichment using Gene Ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG), and STRING database was investigated. Within DS, the LASSO (least absolute shrinkage and selection operator) feature selection was applied.

RESULTS

We identified 253 DEP between DS and HC and 142 DEP between symptomatic and asymptomatic DS. Several pathways regarding inflammatory and neurodevelopmental processes were dysregulated in both analyses. LASSO feature selection within DS returned 15 proteins as potential blood markers.

DISCUSSION

This exploratory proteomic analysis found potential new blood biomarkers for diagnosing DS-AD in need of further investigation.

HIGHLIGHTS

Inflammatory pathways are dysregulated in symptomatic versus asymptomatic DS. NFL and GFAP are confirmed as powerful biomarkers in DS with clinical and/or cognitive decline. Further circulating proteins were identified as potential blood biomarkers for symptomatic DS.

Mitochondria-targeting by small molecules against Alzheimer's disease: A mechanistic perspective

Alzheimer's disease (AD) poses a considerable worldwide health obstacle, marked by gradual cognitive deterioration and neuronal loss. While the molecular mechanisms underlying AD pathology have been elucidated to some extent, therapeutic options remain limited. Mitochondrial dysfunction has become recognized as a significant factor in the development of AD, with oxidative stress and disrupted energy metabolism being critical elements. This review explores the mechanistic aspects of small molecule targeting of mitochondria as a potential therapeutic approach for AD. The review explores the role of mitochondrial dysfunction in AD, including its involvement in the accumulation of β-amyloid plaques and neurofibrillary tangles, synaptic dysfunction, and neuronal death. Furthermore, the effects of oxidative stress on mitochondrial function were investigated, including the resulting damage to mitochondrial components. Mitochondrial-targeted therapies have attracted attention for their potential to restore mitochondrial function and reduce AD pathology. The review outlines the latest preclinical and clinical evidence supporting the effectiveness of small molecules in targeting mitochondrial dysfunction in AD. Additionally, it discusses the molecular pathways involved in mitochondrial dysfunction and examines how small molecules can intervene to address these abnormalities. By providing a comprehensive overview of the latest research in this field, this review aims to shed light on the therapeutic potential of small molecule targeting of mitochondria in AD and stimulate further research in this promising area of drug development.

Calcineurin inhibition may prevent Alzheimer disease in people with Down syndrome

Virtually all people with Down syndrome will develop Alzheimer disease pathology during their lifetime. As Alzheimer disease is the third leading cause of death and a significant factor in end-of-life complications for adults with Down syndrome, identifying interventions is a medical necessity. Calcineurin, a Ca2+/calmodulin-dependent protein phosphatase, has recently been investigated as a possible Alzheimer treatment. This review explores the histories behind Down syndrome and Alzheimer disease, and their intersecting pathologies. This is followed by the role that calcineurin and its U.S. Food and Drug Administration-approved pharmacological inhibitor, tacrolimus, may play in the prevention or treatment of Alzheimer disease. Finally, this review discusses the gap in the literature surrounding the role of calcineurin, its regulators, and calcineurin inhibitors in the context of Down syndrome and comorbid Alzheimer disease. Future studies investigating the role that calcineurin plays in this pathology will be essential in determining the viability of calcineurin inhibitors to treat Alzheimer disease in people with Down syndrome. HIGHLIGHTS: Calcineurin, a Ca2+/calmodulin-dependent protein phosphatase, has become prominent as a possible therapeutic target to treat Alzheimer disease. People with Down syndrome develop Alzheimer pathology as they age, requiring novel therapeutics for treatment. People with Down syndrome may exhibit contraindications to calcineurin inhibition-based therapy, as they overexpress RCAN1 and DYRK1A, regulators of calcineurin. There is a significant gap in the literature involving the expression of calcineurin, RCAN1 and DYRK1A, in people with Down syndrome and Alzheimer disease, which must be addressed to determine the efficacy and safety of newly developed therapeutics.

Decoding the Role of Neurotrophins in Glycogen Synthase Kinase 3-Beta Regulation in Alzheimer's Disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the most prevalent contributor to dementia in elderly individuals. Numerous signalling pathways influencing AD pathophysiology, involving glycogen synthase kinase-3β (Gsk-3β), have been investigated extensively as potential therapeutic targets. Gsk-3β is a critical factor in AD pathogenesis that affects several key hallmarks of the disease notably tau phosphorylation, amyloid-β generation, cognition, neurogenesis, and synaptic integrity. Neurotrophins are small proteins that are critical for maintaining neuronal health and function and may be used to treat neurodegenerative diseases. Notably, the dysregulation of certain neurotrophins and their receptors is also linked with AD which is a major contributor to neurodegeneration. Studies indicated that neurotrophins and their modulators are capable of protecting neurons by blocking the Gsk-3β activity suggesting a potential link for neuroprotection. Neurotrophins support the survival of neurons by regulating Gsk-3β activity. Brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) signalling pathways activate Trk receptors that trigger downstream signalling cascades that subsequently inhibit Gsk-3β activity and reduce AD-related neuropathology. We also explore the role of modulators including phosphatases, kinase cascades, and other regulatory proteins that cross paths with neurotrophin-Gsk-3β signalling. In conclusion, this manuscript summarizes both direct and indirect regulatory roles of neurotrophins and modulators on Gsk-3β to understand the intricate mechanisms driving neurodegeneration in AD.

Cortico-Cortical Paired Associative Stimulation (ccPAS) in Ageing and Alzheimer's Disease: A Quali-Quantitative Approach to Potential Therapeutic Mechanisms and Applications

Background/Objectives: Cognitive decline and Alzheimer's disease (AD) pose a major challenge for the ageing population, with impaired synaptic plasticity playing a central role in their pathophysiology. This article explores the hypothesis that cortico-cortical paired associative stimulation (ccPAS), a non-invasive brain stimulation technique, can restore synaptic function by targeting impaired spike-timing-dependent plasticity (STDP), a key mechanism disrupted in AD. Methods: We reviewed existing studies investigating the effects of ccPAS on neuroplasticity in both ageing and AD populations. Results: Findings suggest age-specific effects, with ccPAS improving motor performance in young adults but showing limited efficacy in older adults, likely due to age-related declines in synaptic plasticity and cortical excitability. In AD, ccPAS studies reveal significant impairments in long-term potentiation (LTP)-like plasticity, while long-term depression (LTD)-like mechanisms appear relatively preserved, emphasising the need for targeted neuromodulation approaches. Conclusions: Despite promising preliminary results, evidence remains limited and largely focused on motor function, with the impact of ccPAS on cognitive domains still underexplored. To bridge this gap, future research should focus on larger and more diverse cohorts to optimise ccPAS protocols for ageing and AD populations and investigate its potential for enhancing cognitive function. By refining stimulation parameters and integrating neuroimageing-based personalisation strategies, ccPAS may represent a novel therapeutic approach for mitigating neuroplasticity deficits in ageing and neurodegenerative conditions.

FTO inhibition mitigates high-fat diet-induced metabolic disturbances and cognitive decline in SAMP8 mice

This study investigated the effects of fat mass and obesity-associated (FTO) inhibition on cognitive function and metabolic parameters of senescence-accelerated mouse prone 8 (SAMP8) mice fed a high-fat diet (HFD). SAMP8 mice fed an HFD exhibited increased body weight, impaired glucose tolerance, and elevated serum leptin levels. In epididymal white adipose tissue (eWAT), pharmacological treatment with FB23, a well-established FTO inhibitor, increased leptin production and modulated genes involved in lipid metabolism (Cpt1a, Atgl, Hsl, Fas), oxidative stress (OS) (Bip, Edem), and inflammation (Mcp1, Tnfα). Expression of hepatic genes related to lipid metabolism (Cpt1a, Atgl, Mgl, Dgat2, Srebp, Plin2) and OS (catalase, Edem) were modulated by FB23, although hepatic steatosis remained unchanged. Remarkably, FB23 treatment increased m6A RNA methylation in the brain, accompanied by changes in N6-methyladenosine (m6A)-regulatory enzymes and modulation of neuroinflammatory markers (Il6, Mcp1, iNOS). FTO inhibition reduced the activity of matrix metalloproteases (Mmp2, Mmp9) and altered IGF1 signaling (Igf1, Pten). Notably, enhanced leptin signaling was observed through increased expression of immediate early genes (Arc, Fos) and the transcription factor Stat3. Improved synaptic plasticity was evident, as shown by increased levels of neurotrophic factors (Bdnf, Ngf) and restored neurite length and spine density. Consistent with these findings, behavioral tests demonstrated that FB23 treatment effectively rescued cognitive impairments in SAMP8 HFD mice. The novel object recognition test (NORT) and object location test (OLT) revealed that treated mice exhibited enhanced short- and long-term memory and spatial memory compared to the HFD control group. Additionally, the open field test showed a reduction in anxiety-like behavior after treatment with FB23. In conclusion, pharmacological FTO inhibition ameliorated HFD-induced metabolic disturbances and cognitive decline in SAMP8 mice. These results suggest that targeting FTO may be a promising therapeutic approach to counteract obesity-induced cognitive impairment and age-related neurodegeneration.

The Potential Mechanism and the Role of Antioxidants in Mitigating Oxidative Stress in Alzheimer's Disease

Alzheimer's disease (AD) is the most prevalent cause of dementia and a significant contributor to health issues and mortality among older individuals. This condition involves a progressive deterioration in cognitive function and the onset of dementia. Recent advancements suggest that the development of AD is more intricate than its underlying brain abnormalities alone. In addition, Alzheimer's disease, metabolic syndrome, and oxidative stress are all intricately linked to one another. Increased concentrations of circulating lipids and disturbances in glucose homeostasis contribute to the intensification of lipid oxidation, leading to a gradual depletion of the body's antioxidant defenses. This heightened oxidative metabolism adversely impacts cell integrity, resulting in neuronal damage. Pathways commonly acknowledged as contributors to AD pathogenesis include alterations in synaptic plasticity, disorganization of neurons, and cell death. Abnormal metabolism of some membrane proteins is thought to cause the creation of amyloid (Aβ) oligomers, which are extremely hazardous to neurotransmission pathways, especially those involving acetylcholine. The interaction between Aβ oligomers and these neurotransmitter systems is thought to induce cellular dysfunction, an imbalance in neurotransmitter signaling, and, ultimately, the manifestation of neurological symptoms. Antioxidants have a significant impact on human health since they may improve the aging process by combating free radicals. Neurodegenerative diseases are currently incurable; however, they may be effectively managed. An appealing alternative is the utilization of natural antioxidants, such as polyphenols, through diet or dietary supplements, which offer numerous advantages. Within this framework, we have extensively examined the importance of oxidative stress in the advancement of Alzheimer's disease, as well as the potential influence of antioxidants in mitigating its effects.

The effect of inhaled nitric oxide treatment on biomarkers of oxidative/nitrosative damage to proteins and DNA/RNA

Inhaled nitric oxide (iNO) is a selective pulmonary vasodilator that is used as a treatment for persistent pulmonary hypertension in neonates (PPHN) with hypoxic respiratory failure. The generation of reactive oxygen and nitrogen species might induce oxidative/nitrosative damage to multiple organs. There is an increasing scientific and clinical interest in the determination of specific biomarkers to measure the degree of oxidative/nitrosative stress in non-invasively collected biofluids. A method for the simultaneous detection of a panel of oxidative and nitrosative stress-related biomarkers for quantifying damage to proteins and DNA/RNA in 20 μL of infant urine samples based on reversed-phase ultra-performance liquid chromatography coupled to tandem mass spectrometry operating in positive electrospray ionization mode (ESI+) was optimized and validated. Infant urine samples from two different studies were analyzed: (i) term and preterm infants from a nutrition study (Nutrishield, N = 50) and (ii) infants with respiratory insufficiency, including infants with PPHN (N = 16) that required iNO treatment and a control group without treatment (N = 14). Eleven of 14 metabolites were detected in >50 % of infant urine samples, with ranges between 0.008 and 1400 μmol/g creatinine. When comparing across groups, differences in samples collected after iNO treatment in comparison to the rest of the groups were found for m-tyrosine (m-Tyr and m-Tyr/Phe) and ortho-tyrosine (o-Tyr and o-Tyr/Phe) (p-values <0.001, Wilcoxon rank-sum test). Positive linear relationships were found with NO exposure corrected by infant weight for m-Tyr, m-Tyr/Phe, o-Tyr, o-Tyr/Phe and 3-nitrotyrosine. Future studies will focus on the evaluation of the impact of iNO treatment on health and oxidative/nitrosative stress-related morbidities associated with prematurity.

Upregulation of p52-ZER6 (ZNF398) increases reactive oxygen species by suppressing metallothionein-3 in neuronal cells

ZNF398/ZER6 belongs to the Krüppel-associated box (KRAB) domain-containing zinc finger proteins (K-ZNFs), the largest family of transcriptional repressors in higher organisms. ZER6 exists in two isoforms, p52 and p71, generated through alternative splicing. Our investigation revealed that p71-ZER6 is abundantly expressed in the stomach, kidney, liver, heart, and brown adipose tissue, while p52-ZER6 is predominantly found in the stomach and brain. The role of p52-ZER6 in neurons has remained unclear. Leveraging open-source RNA-seq data, we identified metallothionein 3 (MT3) as a target gene of p52-ZER6 in mouse hippocampal neuronal HT-22 cells. Through chromatin immunoprecipitation assays, we identified the putative DNA-binding motif (CTAGGGGGGTTGTTATCTCTTTGG) of p52-ZER6 in the promoter region of MT3. Furthermore, we demonstrated an interaction between p52-ZER6 and estrogen receptor alpha (ERα) in the nucleus of SH-SY5Y cells, which led to the inhibition of p52-ZER6's DNA occupancy on the promoter of the MT3 gene. MT3 is a cysteine-rich, low molecular-weight protein known for reducing oxidative stress, reactive oxygen species (ROS), and metal toxicity. Our study revealed that overexpression of p52-ZER6 reduced the levels of MT3, increasing ROS levels, which was mitigated by co-overexpression of ERα. Notably, we also observed upregulation of p52-ZER6 and reduction of MT3 in the cortex of 5xFAD, an Alzheimer's disease (AD) mouse model. These findings suggest a potential pathological mechanism involving p52-ZER6-mediated ROS production in AD pathogenesis.

Nanoscale drug formulations for the treatment of Alzheimer's disease progression

Alzheimer's disease (AD) is a devastating neurodegenerative disorder with no effective disease-modifying treatments. The blood-brain barrier hinders drug delivery to the brain, limiting therapeutic efficacy. Nanoparticle-based systems have emerged as promising tools to overcome these challenges. This review highlights recent advances in nanoparticle technologies for AD treatment, including liposomes, polymeric, inorganic, and biomimetic nanoparticles. These nanoparticles improve drug delivery across the blood-brain barrier, improve stability and bioavailability, and enable targeted delivery to affected brain regions. Functionalization strategies further enhance their therapeutic potential. Multifunctional nanoparticles combining therapeutic and diagnostic properties offer theranostic approaches. While progress has been made, challenges related to safety, targeting precision, and clinical translation remain. Future perspectives emphasize the need for collaborative efforts to optimize nanoparticle design, conduct rigorous studies, and accelerate the development of effective nanotherapeutics. With continued innovation, nanoparticle-based delivery systems hold great promise for revolutionizing AD treatment.

Association of the Lipidome With Alzheimer's Disease and the Mediated Effect of Metabolites: A Two-Step Mendelian Randomization Study

OBJECTIVE

This study aimed to explore the causal effects of lipidome on Alzheimer's disease (AD) and the mediated effects of the metabolites using Mendelian randomization (MR).

METHODS

Data were obtained in genome-wide association studies, and single-nucleotide polymorphisms were screened according to the underlying assumptions of MR. Subsequently, weighted inverse variance was used to analyze the causality of lipidome with AD as well as the mediated effects of metabolites. Finally, MR-Egger, Cochran's Q, and sensitivity analysis were used to assess horizontal pleiotropy, heterogeneity, and robustness of the results, respectively.

RESULTS

The MR analysis showed that phosphatidylcholine (PC) (15:0_18:2) (mediated proportion: 18.30%, p = 0.024) and phosphatidylethanolamine (PE) (18:0_18:2) (mediated proportion: 14.60%, p = 0.028) mediated the reduction of AD risk by lowering betaine levels, which revealed lipidomic susceptibility. The MR-Egger intercept showed no horizontal pleiotropy for all results (p ≥ 0.05). Cochran's Q showed heterogeneity in some of the results. Sensitivity analysis indicated that all results were robust.

CONCLUSION

Our findings reveal the pathways through which PC (15:0_18:2) and PE (18:0_18:2) mediated the reduction of AD risk by lowering betaine levels.

Cuproptosis and copper as potential mechanisms and intervention targets in Alzheimer's disease

Recently study has found a new form of copper-dependent death called cuproptosis, which differs from apoptosis, ferroptosis, and necrosis. The main process of cuproptosis is copper directly combined with lipid-acetylated proteins in the TCA cycle of mitochondrial response, leading to the aggregation of lipid-acetylated proteins and the loss of Fe-S cluster proteins, resulting in mitochondrial dysfunction, and eventually causing cell death. Previous studies demonstrated that an imbalance in copper homeostasis exacerbates the pathological progression of Alzheimer's disease (AD) through the induction of oxidative stress, inflammatory response, and the accumulation of Aβ deposition and tau protein hyperphosphorylation. However, the underlying mechanisms remains to be elucidated. More importantly, research identifies the role of cuproptosis and further elucidates the underlying molecular mechanisms in AD. This review summarized the effects of copper metabolism on AD pathology, the characteristics and mechanism of cuproptosis and we discuss the significance of cuproptosis in the pathogenesis of AD.

Recent Insights into the Neurobiology of Alzheimer's Disease and Advanced Treatment Strategies

In recent years, significant advancements have been made in understanding Alzheimer's disease from both neurobiological and clinical perspectives. Exploring the complex systems underlying AD has unveiled insights that could potentially revolutionize therapeutic approaches. Recent investigations have highlighted intricate interactions among genetic, molecular, and environmental factors in AD. Optimism arises from neurobiological advancements and diverse treatment options, potentially slowing or halting disease progression. Amyloid-beta plaques and tau protein tangles crucially influence AD onset and progression. Emerging treatments involve diverse strategies, such as approaches targeting multiple pathways involved in AD pathogenesis, such as inflammation, oxidative stress, and synaptic dysfunction pathways. Clinical trials using humanized monoclonal antibodies, focusing on immunotherapies eliminating amyloid-beta, have shown promise. Nonpharmacological interventions such as light therapy, electrical stimulation, cognitive training, physical activity, and dietary changes have drawn attention for their potential to slow cognitive aging and enhance brain health. Precision medicine, which involves tailoring therapies to individual genetic and molecular profiles, has gained traction. Ongoing research and interdisciplinary collaboration are expected to yield more effective treatments.

Astrocyte-to-neuron H2O2 signalling supports long-term memory formation in Drosophila and is impaired in an Alzheimer's disease model

Astrocytes help protect neurons from potential damage caused by reactive oxygen species (ROS). While ROS can also exert beneficial effects, it remains unknown how neuronal ROS signalling is activated during memory formation, and whether astrocytes play a role in this process. Here we discover an astrocyte-to-neuron H2O2 signalling cascade in Drosophila that is essential for long-term memory formation. Stimulation of astrocytes by acetylcholine induces an increase in intracellular calcium ions, which triggers the generation of extracellular superoxide (O2•-) by astrocytic NADPH oxidase. Astrocyte-secreted superoxide dismutase 3 (Sod3) converts O2•- to hydrogen peroxide (H2O2), which is imported into neurons of the olfactory memory centre, the mushroom body, as revealed by in vivo H2O2 imaging. Notably, Sod3 activity requires copper ions, which are supplied by neuronal amyloid precursor protein. We also find that human amyloid-β peptide, implicated in Alzheimer's disease, inhibits the nAChRα7 astrocytic cholinergic receptor and impairs memory formation by preventing H2O2 synthesis. These findings may have important implications for understanding the aetiology of Alzheimer's disease.

Exploring the chemical composition and bioactivities of the essential oil of Piper rostratum Roxb

Piperaceae family includes numerous species used for food, spices, and medicinal purposes. In this study, the chemical composition and bioactivities (antioxidant, anticholinesterase, and anti-inflammatory activities) of the essential oil from Piper rostratum Roxb. were investigated. The essential oil was extracted via hydrodistillation and thoroughly analysed using gas chromatography-flame ionisation detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of 20 chemical components were identified, accounting for 94.2% of the total oil. The major components were γ-muurolene (14.1%), δ-cadinene (13.2%), allylpyrocatechol diacetate (11.5%), chavicol (8.2%), α-humulene (7.8%), and hydroxychavicol (6.9%). The antioxidant activity was evaluated using the DPPH free radical scavenging assay, the acetylcholinesterase inhibitory activity was measured using the Ellman method, and the anti-inflammatory activity was assessed through lipoxygenase enzyme inhibition. The essential oil demonstrated moderate activity in DPPH free radical scavenging (IC50 = 98.5 µg/mL), acetylcholinesterase inhibition (IC50 = 89.2 µg/mL), and lipoxygenase inhibition (IC50 = 77.2 µg/mL).

Bacterial exopolysaccharides: Characteristics and antioxidant mechanism

Bacterial exopolysaccharides (EPS) are secondary metabolites of microorganisms which play important roles in adhesion, protection, biofilm formation, and as a source of nutrition. Compared with polysaccharides obtained from animal and plant species, bacterial polysaccharides have significant advantages in terms of production cost and large-scale production due to their abundant metabolic pathways and efficient polysaccharide production capacity. Most extracellular polysaccharides are water-soluble, and some are insoluble, such as bacterial cellulose. Some soluble bacterial EPS also have biological activities such as anticancer, antioxidant, antibacterial and immunomodulatory activities. These biological activities are mainly affected by the molecular weight, monosaccharide type, composition and structure of EPS. In recent years, bacterial EPS are considered as novel functional polysaccharides with important application prospects, especially in free radical scavenging and antioxidation. This review focuses on the characteristics of bacterial EPS, their ability to scavenge free radicals and their corresponding antioxidant mechanisms, and summarizes the relationship between different structures (such as monosaccharide composition, functional groups, molecular weight, etc.) and antioxidant activities. It provides a new idea for the development of more bioactive bacterial EPS antioxidants, points out a new direction for the commercial production of natural, safe and economical polysaccharide drugs and health products.

Inflammatory signaling pathways in Alzheimer's disease: Mechanistic insights and possible therapeutic interventions

The complex pathophysiology of Alzheimer's disease (AD) poses challenges for the development of therapies. Recently, neuroinflammation has been identified as a key pathogenic mechanism underlying AD, while inflammation has emerged as a possible target for the management and prevention of AD. Several prior studies have demonstrated that medications modulating neuroinflammation might lessen AD symptoms, mostly by controlling neuroinflammatory signaling pathways such as the NF-κB, MAPK, NLRP3, etc, and their respective signaling cascade. Moreover, targeting these inflammatory modalities with inhibitors, natural products, and metabolites has been the subject of intensive research because of their anti-inflammatory characteristics, with many studies demonstrating noteworthy pharmacological capabilities and potential clinical applications. Therefore, targeting inflammation is considered a promising strategy for treating AD. This review comprehensively elucidates the neuroinflammatory mechanisms underlying AD progression and the beneficial effects of inhibitors, natural products, and metabolites in AD treatment.

Oxidative pathways of apo, partially, and fully Zn(II)- and Cd(II)-metalated human metallothionein-3 are dominated by disulfide bond formation

Oxidative stress is a key component of many diseases, including neurodegenerative diseases such as Alzheimer's disease. Reactive oxygen species (ROS) such as hydrogen peroxide and nitric oxide lead to disease progression by binding to proteins and causing their dysregulation. Metallothionein-3 (MT3), a cysteine-rich brain-located metalloprotein, has been proposed to be a key player in controlling oxidative stress in the central nervous system. We report data from a combination of electrospray ionization mass spectrometry (ESI-MS), ultraviolet (UV)-visible absorption spectroscopy, and circular dichroism spectroscopy that identify the oxidation pathway of MT3 fully bound to endogenous Zn(II) or exogenous Cd(II) together with the partially metalated species. We characterize the intermediate species formed during the oxidation of MT3, which is dominated by disulfide bond formation. We report the rates of oxidation. For both fully and partially metalated MT3, MT3 is oxidized at 5 to 10 times the rate of MT1, a similar but kidney-expressed isoform of MT. As oxidation progresses, MT3 follows a domain-specific demetallation pathway when it is fully metalated, and a domain-independent pathway when partially metalated. This suggests the presence of a significant susceptibility toward oxidation when MT3 is partially metalated, and, therefore, a possible protective role of Zn(II) when fully metalated. With the evidence for the rapid oxidation rate, our data support the proposals of MT3 as a key antioxidant in physiology.