Search Results (1,534)

Neurodegenerative diseases, including Alzheimer’s Disease (AD), Parkinson’s Disease (PD), Lewy Body Disease (LBD), and related dementias, represent a global health challenge, particularly in aging populations. The simultaneous occurrence of neurodegenerative diseases in an aging population suggests a potential link between causative proteins. Such neurodegenerative proteins, including amyloid-β (Aβ), τ-protein (tau), α-synuclein, TAR DNA-binding protein 43 (TDP-43), and Fused in Sarcoma (FUS), share key characteristics of intrinsically disordered proteins (IDPs), which can explain promiscuous physical interactions, cross-seeding, co-occurrence, pathological synergy, and shared upstream and downstream mechanisms. This review synthesizes current evidence on (1) shared biophysical features of neurodegeneration-associated proteins, (2) mechanisms driving mixed neuropathology, (3) therapeutic implications of disorder-driven interactions, and (4) key unresolved questions shaping future research. By framing neurodegeneration as a network of interacting, disorder-driven proteinopathies rather than isolated entities, this perspective highlights the need for integrative, systems-level approaches to better understand disease heterogeneity and to identify novel targets for intervention. Full article

Alzheimer’s disease (AD) is the most prevalent form of dementia and is characterized by abnormal aggregation of β-amyloid (Aβ) peptides, tau proteins, and neuroinflammation in the central nervous system (CNS). While most AD research has focused on the brain, the molecular pathology of the spinal cord remains poorly understood. In this study, we investigated amyloid pathology, neurodegeneration, neuroinflammation, and cholesterol metabolism across distinct regions of the spinal cord and examined sex-specific differences using a model of AD, 5xFAD mice. Our data reveal that Aβ accumulation was restricted to the cervical spinal cord at 3 months but was evident in all areas of the spinal cord by 9 months, with similar patterns in both female and male animals. Despite this early and progressive Aβ deposition, no significant neuronal loss was observed in the ventral horn of the cervical spinal cord in either sex at 3 or 9 months of age. In contrast, there was a significant positive correlation between Aβ deposition and Iba1+ cell density in the spinal cord of 5xFAD mice. The number of Iba1+ cells in both the grey and white matter was significantly increased in female and male 5xFAD mice compared with age-matched wild-type (WT) littermates at 9 months of age. Astrocytic responses, however, were sex-specific: female, but not male, 5xFAD mice exhibited a significant increase in GFAP+ astrocytes in the grey matter of the thoracic and lumber spinal cord at 9 months compared with 3 months and relative to age-matched WT controls in the cervical and thoracic spinal cord. Furthermore, GFAP+ area in the thoracic spinal cord was significantly higher in female 9-month-old 5xFAD mice compared with their male counterparts, indicating a female-specific astrocytic response in AD spinal cord pathology. Our data also show an increase in free cholesterol (Filipin+ area) in 5xFAD mice at 9 months relative to WT controls, accompanied by altered expression of cholesterol metabolism genes, including downregulation of Abca1, Cyp46a1 and Cyp27a1. Collectively, these findings provide new insights into AD progression in the spinal cord, highlighting molecular pathology of AD extending beyond the brain. Full article

Alzheimer’s disease (AD) is the leading cause of dementia, responsible for approximately 60–70% of cases globally. AD is a gradually progressive neurodegenerative disorder that is characterized by widespread deposition of β-amyloid (Aβ) plaques, followed by aggregation of tau protein in the neocortex, neurodegeneration, and cognitive decline. Within these complex pathological interactions, Aβ and tau proteins, together with astrogliosis, neuroinflammation, and other factors, play a key role in the development of clinical AD. Accumulating evidence indicates that the formation of protein oligomers, followed by their aggregation into pathological fibrils, constitutes an early and critical step in the pathogenesis of the disease. Specific pathological proteins are often treated as biomarkers of particular diseases because their presence, concentration, or altered structure reflects an underlying disease process. It is well established that the Aβ and tau proteins are the key hallmarks of AD, and their mutual interaction may significantly influence the pathology of the disease. Early diagnosis is crucial for maximizing the therapeutic benefits of currently available symptomatic treatments, which can alleviate symptoms and modestly delay clinical deterioration in patients with AD. This review highlights the mechanisms involved in protein-dependent neurodegeneration and describes both traditional and novel approaches for the cure of AD. The most important aspect of this publication is the integration of the two key proteins: Aβ and tau, and the resulting shift toward a new therapeutic approach. Full article

DP-128 is a multitarget benzonaphthyridine-6-chlorotacrine hybrid molecule with potent in vitro anticholinesterase and Aβ42 and tau anti-aggregating activity. While often used as a reference protein aggregation inhibitor, its further development as an anti-Alzheimer agent is limited by significant cytotoxicity, suboptimal aqueous solubility and microsomal stability. Since these drawbacks might arise from its rather high lipophilicity, in this work we have developed a series of more polar analogues, designed by structural modifications at the benzonaphthyridine or 6-chlorotacrine moieties or within the eight-atom linker. Half of the new analogues are indeed slightly more soluble and clearly less cytotoxic than DP-128, display single-digit acetylcholinesterase inhibitory activity, and retain the Aβ42 and tau anti-aggregating potency of the lead, as well as favourable brain permeation and high plasma stability. While further optimization of microsomal stability is necessary for a potential therapeutic use of this class of compounds, hybrids 16 and 17, with similar or even higher Aβ42 and tau anti-aggregating activity and lower cytotoxicity than DP-128, might represent novel pharmacological tools for protein aggregation studies. Full article

Alzheimer’s disease (AD) is characterized by progressive cognitive decline and the accumulation of amyloid-β (Aβ) plaques and tau neurofibrillary tangles. Beyond genetic and proteostatic mechanisms, infection- and dysbiosis-based models of AD have gained renewed attention, including the antimicrobial protection hypothesis, in which Aβ may participate in innate immune defense. Here, we reanalyzed ribosomal depleted (Ribo-Zero) RNA-seq data from dorsolateral prefrontal cortex (DLPFC) samples from the Mount Sinai Brain Bank cohort (GSE53697) to screen for non-human transcripts. Reads underwent quality control and adapter trimming, taxonomic classification with Kraken2, abundance re-estimation with Bracken, and differential abundance testing with edgeR. Across 17 samples (9 advanced AD and 8 controls), we detected low-biomass microbial signals, with Acinetobacter radioresistens showing enrichment in the AD group (FDR = 0.018). Several additional taxa showed suggestive group differences but did not remain significant after multiple testing correction, including Lactobacillus iners (FDR = 0.051). We also performed an exploratory in silico analysis of an A. radioresistens biofilm-associated protein homolog, identifying predicted amyloidogenic motifs and surface-exposed regions that may be relevant to cross-seeding hypotheses, although no mechanistic inference can be drawn without experimental validation. Given the technical challenges of inferring microbial signals from post-mortem brain RNA-seq data, including contamination risk, low microbial biomass, and overwhelming host background, these findings should be interpreted as hypothesis-generating and warrant orthogonal validation in larger, microbiome-aware cohorts. Full article

The increasing prevalence of obesity and Alzheimer’s disease (AD) in the aging population underscores an urgent need to understand the common cellular and metabolic mechanisms they share. Accumulated evidence suggests that overlapping metabolic disturbances contribute to the pathogenesis of these two conditions. In this review, we highlight key underlying interconnecting metabolic pathways: (1) adipose-brain crosstalk mediated by adipokines and adipose tissue-derived extracellular vesicles that can modulate neuronal function and amyloid pathology, (2) dysregulated lipid metabolism affecting cholesterol, sphingolipids, and phospholipids and thereby promoting inflammation, amyloid precursor protein processing, and tau hyperphosphorylation, (3) impaired glycolysis and insulin resistance, which accelerate both obesity and neurodegenerative processes, (4) mitochondrial dysfunction marked by disrupted tricarboxylic acid cycle enzymes and electron transport chain complexes, leading to elevated reactive oxygen species and driving both obesity and AD pathology, and (5) gut microbiota dysbiosis, which can trigger inflammation as well as amyloid and tau aggregation. Together, these mechanisms show that metabolic alterations appear early, preceding clinical disease, and that understanding these underlying connections can provide strategies to protect metabolic health and prevent disease progression. Full article

Neurodegenerative diseases arise when normally functional aggregation-prone proteins transition into stable cross-β amyloid fibrils. Although these fibrils share a conserved architecture, the pathways that lead to fibrillation vary across proteins and cellular environments. Liquid–liquid phase separation is now recognized as a central organizer of intracellular biochemistry that modulates protein aggregation. Physiological condensation can buffer aggregation by maintaining macromolecular solubility and providing partner interactions that compete against pathological protein–protein interactions. However, condensates can transform and age into gel-like states that can favor the emergence of β-rich oligomers and solid-state fibrils. Across six disease-linked proteins that include Tau, ⍺-synuclein, amyloid-β, TDP-43, FUS, and hnRNPA1, we compare how sequence-encoded interaction motifs, cellular cofactors, and interfacial microenvironments shape the balance between physiological condensates and pathological amyloids. Here, we highlight the unifying drivers of aggregation and intervention points that preserve native function while limiting toxic amyloid formation. Full article

Mild behavioral impairment (MBI) is a clinical syndrome characterized by the late-life onset and persistence of neuropsychiatric symptoms (NPSs), representing a change from longstanding behavior or personality and considered a potential prodrome of neurodegenerative disease. MBI is classified into five domains: decreased motivation, affective dysregulation, impulse dyscontrol, social inappropriateness, and psychotic symptoms. In this narrative review, we synthesize clinical, neuroanatomical, and molecular evidence linking MBI to the spectrum of tauopathies, including Alzheimer’s disease (AD), frontotemporal spectrum disorders (FTSDs), and primary four-repeat tauopathies such as progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). Emerging evidence suggests that early behavioral symptoms associated with MBI may reflect the selective vulnerability of frontolimbic, salience, default mode, and frontostriatal networks to tau-mediated neurodegeneration. Mechanistically, converging findings support roles for tau-related synaptic dysfunction, including synaptotoxic soluble tau species, cytoskeletal and axonal transport disruption, monoaminergic neurotransmitter imbalance in brainstem systems, and neuroinflammatory and glial pathways. We also highlight genotype-related behavioral profiles in genetic frontotemporal lobar degeneration and discuss how scalable blood-based biomarkers, including neurofilament light chain, glial fibrillary acidic protein, and plasma phospho-tau species, may complement MBI-based phenotyping for differential diagnosis and prognostic stratification in clinical research. Full article

Recent studies support the concept of a bidirectional lung–brain axis. While neural, immune, and microbial pathways are increasingly recognized in lung-to-brain communication, the role of matrikines—bioactive peptides generated by extracellular matrix (ECM) proteolysis during remodeling—in this inter-organ communication remains underexplored. This review highlights matrikines originating from the lung, particularly the collagen-derived tripeptide Pro-Gly-Pro (PGP) and the elastin-derived hexapeptide Val-Gly-Val-Ala-Pro-Gly (VGVAPG), as potential mediators linking pulmonary pathology with neurological outcomes. The lung is rich in ECM proteins, and inflammatory conditions such as chronic obstructive pulmonary disease (COPD) and emphysema trigger proteolytic activity by matrix metalloproteinases (MMPs) and neutrophil elastase, releasing matrikines into circulation. Under conditions of blood–brain barrier (BBB) dysfunction, they may access the central nervous system (CNS), where they influence neurons, microglia, and astrocytes, modulating neuroinflammation, autophagy, and synaptic integrity. While PGP can exhibit context-dependent neuroprotective effects, its acetylated form and VGVAPG are associated with neurotoxicity, Tau hyperphosphorylation, and microglial activation. Additional matrikines, including Gly-His-Lys (GHK) and endorepellin, may further modulate CNS homeostasis. Collectively, these findings support lung-derived matrikines as circulating mediators of lung-to-brain signaling, providing a novel mechanistic framework linking chronic pulmonary inflammation to neuropathologies, such as stroke and neurodegenerative disorders, and highlighting potential targets for therapeutic intervention. Full article

Alzheimer’s disease (AD) is a neurodegenerative disorder first described more than one century ago. Over this time, many features of the disease have been discovered and, consequently, many different approaches in the diagnosis and treatment of AD have been developed. A major assumption has guided research on AD in the past: this fatal form of cognitive decline is believed to have a pathogenic basis in the deposition of amyloid beta (Aβ) aggregates throughout the brain. Consequently, a main goal of AD therapy is to reduce Aβ load, and several monoclonal antibodies targeting amyloid are among the most recent approaches to AD treatment. However, the effectiveness of these drugs is limited, as they cannot block the progression of the disease; they only slow it down in certain conditions. Many other causative factors are known to promote the development of the disease, with immune system involvement being the most investigated. Indeed, it has been well documented that the microglial response enhances the deposition of other altered proteins, such as Tau, and induces a neurotoxic microenvironment that promotes neuronal loss. In this scenario, the interaction between microglia and astrocytes is known to accelerate pathogenic processes, and a possible role for peripheral T lymphocytes in AD pathology has also been described. An interesting hypothesis is that immune cells driving chronic inflammation might worsen AD progression and, therefore, could represent a target for treatment strategies in this disease. Thus, this review article aims to summarise the role of brain and peripheral immune molecules and cells in AD. Also, immune-based treatments for AD are described, including those targeting microglia and T cells. Full article

Taurine is abundant in seminal plasma and is involved in redox balance, osmoregulation, and sperm membrane stability. However, its role in protecting dairy goat bucks against heat stress-associated declines in sperm quality remains unclear. In this study, eighteen Guanzhong dairy goat bucks were assigned to three groups: control (NC), field heat stress (HS), and HS with taurine supplementation (HS + Tau). Heat stress reduced seminal plasma taurine abundance and was associated with metabolic reprogramming, impaired sperm quality, disturbed redox homeostasis, and decreased LH and testosterone levels. Specifically, HS reduced sperm motility, viability, membrane integrity, and kinematic performance, increased sperm abnormalities, and shortened in vitro sperm survival time. Taurine supplementation alleviated these adverse changes and shifted the seminal plasma metabolome toward a more homeostatic profile. Metabolomic analysis indicated that HS was associated with the accumulation of long-chain acylcarnitines in seminal plasma. Complementary mouse and TM4 Sertoli cell experiments provided preliminary mechanistic support, suggesting that taurine may partially protect Sertoli cell tight-junction proteins, particularly ZO-1, under heat- and acylcarnitine-related stress, and may be associated with the modulation of p38/AKT signaling. Collectively, these findings suggest that taurine alleviates heat stress-induced declines in sperm quality in dairy goat bucks, at least in part, by modulating seminal plasma metabolism. Full article

Systemic autoimmunity plays an important role in pathogenesis of neurodegenerative diseases. The objective of our study was to explore the seroprevalence of naturally occurring autoantibodies (Aabs) targeting a panel of 14 antigens broadly involved in neurodegenerative diseases such as Alzheimer’s Disease, Parkinson’s Disease, frontotemporal dementia, and vascular dementia. Commonly associated proteins with underlying neuronal pathology of the brain include amyloid-beta (Aβ), tau, alpha-synuclein (α-syn), TDP-43, and FUS. Proteins associated with glial and astrocytic involvement—TREM2 and Chi3Li; proteins related to myelin damage and axonal degeneration—light neurofilaments (NFL), myelin basic protein (MBP); synaptic loss reflected by neurogranin (NRGN), a marker of neuronal injury—neuron specific enolase (NSE); and markers of disturbed calcium homeostasis—VSNL1 and neuroinflammation—MCP-1. Presence and levels of plasma IgG against these antigens were examined using enzyme-linked immunosorbent assay (ELISA) method in patients with dementia, patients with mild cognitive impairment (MCI), and healthy age-matched controls. Aabs against all selected antigens were detected across all groups, including healthy control, with varied seroprevalence levels. For the first time, we report the presence of anti-FUS, anti-TREM2, anti-NRGN, anti-VSNL1, anti-NSE, and anti-MCP1 Aabs. Elevated anti-Chi3Li Aabs in individuals with MCI indicate a disease-associated immune signature linked to early neurodegenerative processes. Overall, these results provide evidence of systemic immune activation accompanying neurodegeneration, underscore the complexity of immune involvement, and highlight the importance of targeting multiple pathological pathways in future immunomodulatory strategies. Full article

Prostaglandin E₂ (PGE₂) plays a critical role in regulating uterine endometrial function and supporting embryonic development during early pregnancy in ruminants. However, its precise roles in shaping the uterine microenvironment remain unclear. Herein, 1 mg PGE₂ was infused daily into the uterus of dairy heifers from days 12 to 14 of the estrus cycle. ULF was subsequently collected for integrated proteomic, metabolomic, and targeted lipidomic analyses. In addition, bovine endometrial epithelial cells were used to evaluate the effects of PGE₂ on epithelial adhesion and responsiveness to interferon tau (IFNT). PGE₂ infusion resulted in 909 differentially abundant proteins (DAPs), which are primarily associated with early embryonic development, immune regulation, and cell adhesion. Untargeted metabolomics analysis identified 587 altered metabolites, which were enriched in sphingolipid, arachidonic acid, phenylalanine, and tryptophan metabolism. Proteomic–metabolomic analyses showed that these alterations were primarily associated with early embryonic development, immune regulation, and cell adhesion. Targeted lipidomic analysis showed a global reduction in lipid accumulation, with glycerophospholipid metabolism and choline metabolism most significantly affected. In vitro, PGE₂ reduced epithelial microvilli density, increased osteopontin (OPN) expression, and decreased the expression of junctional proteins (zona occludens-1 (ZO-1), E-cadherin (CDH1), and fibronectin 1 (FN1)). Moreover, PGE₂ enhanced the responsiveness of bEECs to IFNT by interferon alpha/beta receptor 1 (IFNAR1) and IFNAR2, and prostaglandin E receptor 4 (PTGER4) was identified as the primary receptor mediating this response. Collectively, these findings suggest that PGE₂ may modulate lipid metabolism and adhesion-related processes in the endometrium and influence endometrial responsiveness to IFNT, providing insights into molecular mechanisms associated with pregnancy establishment in dairy cows. Full article

Genotoxic stress, which includes DNA damage and the mis-localization of DNA and RNA, is a defining feature of tauopathies, Alzheimer’s disease, and several other neurodegenerative disorders. Recent findings indicate that activation of the innate immune system in response to genotoxic stress can drive harmful neuroinflammation, compromise neuronal integrity, and promote neurodegeneration. Multiple innate immune sensors of genotoxic stress have recently been discovered, but the contributions of many of these emerging nucleic acid–sensing pathways in neurodegenerative disease pathogenesis remain largely unexplored. Z-DNA binding protein 1 (ZBP1) is one such recently discovered genotoxic stress sensor that has been shown to incite various forms of cell death as well as proinflammatory cytokine production in response to left-handed Z conformations of DNA (Z-DNA) and RNA (Z-RNA). Here, we show that ZBP1 deletion provides protection against tau pathology and neuronal loss in the PS19 mouse model of tauopathy. Moreover, we find that this rescue of tauopathy seen with ZBP1 ablation is associated with dampened activation of microglia and astrocytes. These findings identify ZBP1 as a pivotal genotoxic stress sensor that drives tau pathology, gliosis, and neuronal loss in tauopathy. This work further suggests that targeting ZBP1 may offer a therapeutic strategy to treat tau-mediated neurodegenerative disease. Full article

Type 2 Diabetes (T2D) is characterized by the toxic aggregation of human islet amyloid polypeptide (hIAPP or amylin) within pancreatic β-cells. IAPP is also a neuropancreatic hormone that plays a significant role in Alzheimer’s disease (AD) by co-depositing with amyloid-beta (Aβ) and Tau, supporting the Type 3 Diabetes (T3D) hypothesis. Soluble IAPP accelerates Aβ aggregation through cross-seeding and causes neurotoxicity by impairing the blood–brain barrier and activating neuroinflammation. Melatonin inhibits these processes by disrupting hydrophobic interactions in both hIAPP and Aβ, preventing the formation of toxic β-sheet structures. Furthermore, melatonin promotes amyloid clearance via the glymphatic and lymphatic systems, protects neurons from oxidative damage, and reduces Tau hyperphosphorylation. This suggests that melatonin serves as a promising multitarget therapeutic agent for both metabolic and neurodegenerative disorders by modulating structural protein transformations. Full article