Search Results (247)

Neurodegenerative diseases arise from interacting oxidative, inflammatory, mitochondrial, and proteostatic disturbances. Hydroxytyrosol (HT), an olive phenol, has been proposed as a multitarget neuroprotective compound. This narrative review integrates HT chemistry, parent/metabolite pharmacokinetics, blood–brain barrier (BBB) evidence, mechanisms, disorder-specific models, and human studies. Direct HT evidence is strongest for nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) activation and experimental modulation of α-synuclein; support for AMP-activated protein kinase (AMPK)/sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), mitochondrial protection, nuclear factor-kappa B (NF-κB)-related inflammation, and amyloid-β (Aβ) is predominantly preclinical, whereas tau, autophagic flux, and ubiquitin–proteasome effects remain preliminary. Oral HT is rapidly absorbed but extensively conjugated, and no study has quantified parent HT or its major metabolites in the human brain or cerebrospinal fluid after oral supplementation. Isolated-HT trials show systemic antioxidant or anti-inflammatory biomarker effects, while cognitive findings derive mainly from phenolic-rich olive matrices and cannot be assigned to HT alone. No disease-modifying efficacy has been established for isolated HT in Alzheimer’s disease (AD), Parkinson’s disease (PD), or related disorders. HT is therefore a mechanistically plausible candidate, but human brain exposure, dose–response, and efficacy require adequately powered disease-specific trials. Full article

Neurodegenerative diseases represent a major and growing global health burden. Although these disorders are often clinically defined by symptoms and affected brain regions, many are mechanistically linked to abnormal protein accumulation, misfolding, impaired proteostasis, RNA dysregulation, mitochondrial dysfunction, and neuroinflammation. In this Perspective article, I discuss major neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, dementia with Lewy bodies, multiple system atrophy, amyotrophic lateral sclerosis, frontotemporal dementia, Huntington’s disease, prion diseases, spinocerebellar ataxias, and spinal muscular atrophy, through the lens of disease-associated proteins and experimental modeling. I argue that a protein-centered framework provides a useful approach for understanding disease mechanisms and selecting transgenic mouse models, while recognizing that aging, cellular context, neuroinflammation, mitochondrial dysfunction, vascular dysfunction, and other disease modifiers also shape neurodegeneration. Transgenic and genetically engineered mouse models have been essential for dissecting the pathogenic roles of amyloid-β, tau, α-synuclein, TDP-43, SOD1, FUS, C9ORF72-associated dipeptide repeat proteins, mutant huntingtin, prion protein, ataxins, and SMN deficiency. However, these models have important limitations, including artificial overexpression, familial mutation bias, species differences, and incomplete representation of aging-related sporadic diseases. Rather than seeking a single “best” model, a more productive strategy is to adopt model portfolios tailored to specific biological questions and to integrate mouse studies with human cellular models, postmortem tissue, omics approaches, and biomarker-based validation. Such an approach may improve mechanistic insight, strengthen translational relevance, and enhance the predictive value of preclinical neurodegenerative disease research. Full article

The synuclein family, comprising α-, β-, and γ-synucleins, consists of highly conserved, intrinsically disordered proteins sharing substantial structural homology and exhibiting multifunctional roles in membrane interactions, vesicle trafficking, lipid homeostasis, and cellular signalling. Synucleins are enriched at presynaptic terminals, where they regulate synaptic vesicle dynamics and neurotransmission by contributing to vesicle clustering, trafficking, and the availability of vesicles for release. Aberrant expression, misfolding, and aggregation of synucleins are associated with several human diseases, particularly neurodegenerative disorders and certain cancers, highlighting their biological and clinical relevance. The primary aim of this review was to provide a focused overview of current knowledge regarding the physiological presynaptic functions of synucleins. By concentrating on this relatively underexplored aspect of synuclein biology, we sought to highlight their roles in synaptic transmission and presynaptic regulation, thereby complementing the extensive literature devoted to their pathological significance. Here, the recent findings on the contributions of α-, β-, and γ-synucleins to synaptic vesicle organization, trafficking and neurotransmitter release were summarized, and their emerging roles in maintaining presynaptic homeostasis were discussed. In addition, we consider how disruption of these physiological functions may contribute to synaptic dysfunction and the development of disease. Full article

Background/Goals: Traumatic brain injury (TBI) is increasingly recognised as an important risk factor for delayed neurodegeneration and has been implicated in the modulation of Alzheimer’s disease (AD)-related amyloid pathology. However, experimental evidence remains equivocal, suggesting that the effects of TBI on amyloidogenesis are context-dependent and influenced by factors including disease stage, injury severity, and the pre-existing neurodegenerative background. This study aimed to comprehensively assess the effects of TBI on cognitive function, synuclein-family gene expression, neuroinflammatory gene expression and amyloid plaque morphology in APPswe/PS1dE9/Blg mice. Methods: Wild-type and APP/PS1 mice were assigned to four experimental groups: WT, WT-TBI, APP/PS1 and APP/PS1-TBI. TBI was induced at 6 months of age using a controlled cortical impact device (precision impactor). Behavioural assessments were conducted at two post-injury time points to evaluate locomotor activity, object recognition memory, short-term spatial memory and spatial learning. Cortex and hippocampus samples were analysed by qRT-PCR to evaluate synuclein-family gene expression and neuroinflammation-related markers. Amyloid plaque pathology was evaluated in Congo red-stained brain sections using QuPath-based image analysis. Results: TBI did not induce a consistent increase in amyloid plaque burden in APP/PS1 mice. Instead, TBI was associated with changes in plaque-size distribution, particularly at the later post-injury time point. Behavioural assessments revealed early trauma-associated cognitive impairmen; whereas, impairments observed at later stages appeared to be driven predominantly by progression of the APP/PS1 phenotype. Gene expression analysis revealed region- and genotype-dependent alterations in synuclein-family transcripts and inflammatory markers with the most pronounced changes observed in the cortex. Conclusions: These findings indicate that TBI does not uniformly accelerate β-amyloid deposition in APP/PS1 mice with established amyloid pathology. Rather, TBI appears to modify the temporal progression and morphological characteristics of amyloid pathology while interacting with genotype-dependent transcriptional responses involving synuclein-family genes and neuroinflammatory pathways. These results highlight the complex interplay between traumatic injury and pre-existing neurodegenerative processes and warrant further studies at the protein-level and over extended follow-up periods to elucidate the underlying mechanisms. Full article

Natural coumarins are a structurally privileged group of bioactive benzopyranone lactones widely spread across the Apiaceae, Rutaceae, and Leguminosae families, and hold significant potential as inhibitors of pathological protein aggregation in Alzheimer’s disease, Parkinson’s disease, and type 2 diabetes mellitus. The fully planar, rigid bicyclic structure of the coumarin nucleus (~3.4–3.5 Å thickness) is geometrically compatible with intercalative π–π stacking with aggregation-nucleating aromatic residues, including Phe19 of Aβ(1–42), providing a mechanistically coherent pharmacophoric basis for anti-aggregation activity according to computational and indirect biophysical evidence. This review critically evaluates the peer-reviewed literature on naturally occurring coumarins and their synthetic derivatives as candidate β-sheet intercalators, with analysis of SAR at C-3 to C-8 positions; multi-target-directed ligand designs with dual activities of inhibiting AChE, BACE-1, GSK-3β, and MAO-B, and as blood–brain barrier-penetrating neuroprotective agents validated in cellular and rodent models. The critical analysis identifies the translational gap between in vitro IC₅₀ values and attainable brain drug concentrations as the primary pharmacological obstacle. It identifies the absence of systematic investigation of coumarin against IAPP, a directly relevant amyloid target in metabolic neurodegeneration, as the most significant unmet research priority in the field. Full article

Neurodegenerative diseases (NDs), such as Alzheimer’s disease (AD), Parkinson’s disease (PD), Amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD), involve the gradual loss of structure or function of neurons in the nervous system and are an increasing threat to the aging population worldwide. Although these disorders have different clinical features which affect cognition, movement and other vital body functions, they share key underlying molecular and cellular processes. This starts with protein misfolding and aggregation, mitochondrial dysfunction, oxidative stress, dysregulated protein homeostasis, neuroinflammation, and disrupted cell death pathways. Recent findings have added disease-specific processes, like amyloid-β and tau aggregates in AD, α-synuclein aggregation and mitophagy failure in PD’s, TDP-43-related impaired RNA metabolism in ALS, and mutant huntingtin causing transcription aberrations in HD. Protein interactome network analysis showed mechanistic crosstalk between pathogenic proteins of AD and PD. New evidence highlights how lysosomal dysfunction, endoplasmic reticulum stress, and microglial activation, act as a common axis in neurodegeneration. Advancements in genomics and epigenomics have found shared genetic risk loci and regulatory processes that affect how diseases develop and progress. Simultaneously, new biomarkers like circulating microRNAs, exosome-related pathological proteins, neurofilament light chain, inflammatory cytokines, and microglial activation markers are powering early diagnosis tools and disease variations. New imaging techniques also allow for the identification of protein aggregations before symptoms appear. Overall, these findings are accelerating targeted treatments and personalized medicine aimed at disease progression. This review highlights current insights into the molecular mechanisms of NDs and discusses new biomarkers and treatment targets that help future diagnostic and treatment strategies. Full article

The voltage-dependent anion channel (VDAC) is the primary conduit for ion and metabolite transport across the mitochondrial outer membrane. Positioned at the interface between the cytosol and the mitochondrial compartment, VDAC is uniquely accessible to proteins on both sides of the membrane, making it an interaction hub whose biophysical properties and signaling functions are shaped by protein complexation in addition to its intrinsic pore specialization. Mammals express three isoforms—VDAC1, VDAC2, and VDAC3—sharing a conserved β-barrel scaffold with about 70% identity. However, minor differences in the sequence lead to drastic changes in VDAC isoform affinity with other proteins. Here, we review the molecular mechanisms and physiological consequences of VDAC complexation with a set of well-characterized partners: hexokinase, dimeric tubulin, α-synuclein, mitochondria-associated membrane proteins, B-cell lymphoma 2 (BCL-2) family proteins, and the translocase of the outer membrane (TOM) protein import complex. For each complex, we evaluate the available structural, biophysical, and genetic evidence for isoform specificity, highlight where mechanistic understanding is most advanced, and identify open questions. A consistent principle emerges across all complexes: functionally nonredundant isoform contributions are primarily governed by differential partner affinity and complexation, rather than by differences in pore architecture alone. This framework has direct implications for mitochondria-associated pathologies, including cancer, cardiovascular disease, and neurodegeneration, as well as for the rational design of VDAC-targeting therapeutics. Full article

Background/Objectives. Parkinson’s disease (PD) is a multifactorial neurodegenerative disorder characterized by dopaminergic neuron loss, α-synuclein pathology, neuroinflammation, and cognitive decline. Synaptamide (N-Docosahexaenoylethanolamine (DHEA)) is an endogenous lipid mediator with documented anti-inflammatory and neurogenic properties, but its effects in PD models remain unexplored. This study aimed to evaluate the neuroprotective potential of synaptamide in a subchronic MPTP-induced mouse model of PD. Methods. Male C57BL/6 mice received MPTP (30 mg/kg/day, i.p., 5 days) with or without synaptamide (10 mg/kg/day, s.c., 13 days). Behavioral tests (open field, Y-maze, elevated plus maze, novel object recognition (NOR)) were performed, followed by immunohistochemical analysis of tyrosine hydroxylase (TH)-positive neurons in the substantia nigra, and Western blotting for α-synuclein, p-α-synuclein, TH, and IL1β in brain homogenates and serum. In vitro Neuro-2a cells were co-treated with MPP⁺ (100 µM) and synaptamide (0.1–10 µM) for cytotoxicity assessment (MTS assay). Results. Synaptamide (10 µM) significantly attenuated MPP⁺-induced cytotoxicity in Neuro-2a cells. In vivo, MPTP caused a marked loss of TH⁺-neurons in the substantia nigra, which was prevented by synaptamide treatment. Importantly, this subchronic MPTP model recapitulates early biochemical alterations (e.g., α-synuclein phosphorylation at Ser129) rather than mature Lewy body pathology, a limitation that should be considered when interpreting these findings. Although no motor deficits or anxiety-like behavior were observed, the NOR test revealed MPTP-induced long-term memory impairment, which was fully restored by synaptamide. Conclusions. These findings suggest that synaptamide may exert effects on pathological processes associated with PD, warranting further investigation into its potential role in combination or supportive therapy for this disease. Full article

Parkinson’s disease and Alzheimer’s disease are currently classified as a major global health burden, sharing a defining pathological hallmark represented by insoluble protein aggregates of α-synuclein (α-syn) and amyloid-β (Aβ), respectively. A defining characteristic of all amyloids is a highly ordered, unbranched filamentous morphology, where individual β-strands align perpendicularly to the filament axis. Despite recent technological advances, direct observation of protein conformational changes and amyloid formation in biological samples remains a challenge as well as the quantification of pathological aggregates in liquid biopsies. This review critically recapitulates the major advances in the application of Raman spectroscopy (RS) and surface-enhanced Raman spectroscopy (SERS) in the investigation of pathological protein aggregates in neurological disorders, with a focus on α-syn and Aβ. We discuss both in vitro structural characterization and the applications to biological and clinical samples, outlining the main challenges for clinical translation, including the need for standardized protocols. Recent achievements in the use of RS and SERS on liquid biopsies and other clinical samples are paving the way for further implementation of Raman-based approaches for the diagnosis of neurodegenerative disorders. Full article

Neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS; Lou Gehrig’s disease), represent a growing global health burden characterized by progressive neuronal loss and functional decline. Despite decades of intensive research, effective disease-modifying therapies remain limited, underscoring the urgent need for innovative therapeutic strategies. This review highlights recent advances in the understanding of disease etiology and emerging treatment approaches, with a particular focus on modalities with translational potential. We discussed novel disease-modifying interventions, including gene and cell therapies, RNA-targeting strategies, and immunotherapies aimed at clearing misfolded proteins such as amyloid-β, tau, and α-synuclein. In parallel, we examined the evolving recognition of neuroinflammation and mitochondrial dysfunction as actionable therapeutic targets, alongside progress in precision medicine and biomarker-guided approaches that enable early diagnosis and individualized treatment. Additionally, we summarized developments in repurposed pharmacological agents, neuroprotective compounds, and lifestyle interventions, emphasizing the importance of integrative, multimodal strategies. Across AD, PD, and ALS, convergent molecular mechanisms, including protein misfolding, oxidative stress, and disrupted proteostasis, present opportunities for cross-disease therapeutic targeting. Finally, we addressed key challenges and future directions, including translating preclinical efficacy into clinical success, optimizing CNS-targeted delivery systems, and navigating ethical considerations surrounding gene editing and stem cell therapies. Full article

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

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, α-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

Alzheimer’s (AD) and Parkinson’s disease (PD) are prominent neurodegenerative disorders characterized by early synaptic loss, which correlates more closely with clinical symptoms than neuronal death. This synaptic impairment is primarily driven by disruptions in synaptic vesicle (SV) trafficking, a critical process for maintaining synaptic integrity through a tightly regulated cycle involving clustering, docking-priming, Ca²⁺-triggered fusion, and endocytosis. In AD, amyloid-β (Aβ) oligomers interfere with SNARE-mediated fusion and endocytosis, while hyperphosphorylated tau obstructs vesicle mobility and docking, resulting in cumulative toxicity that aggravates SV defects. Conversely, in PD, α-synuclein (α-syn) aggregation alters vesicle clustering, membrane fusion, and recycling, and these effects are further influenced by Leucine-rich repeat kinase 2 (LRRK2)-Rab-related trafficking defects and the selective vulnerability of dopaminergic terminals. Different from previous reviews that address synaptic dysfunction in a broader manner, the present review is specifically organized around the SV trafficking cycle and compares both shared presynaptic endpoints and disease-specific upstream mechanisms in AD and PD. In addition, recent mechanism-oriented therapeutic strategies are summarized. This vesicle-cycle-centered perspective may provide a clearer framework for understanding presynaptic pathology and for guiding the development of earlier and more targeted interventions. Full article

Introduction: Olives have been used in traditional Mediterranean medicine for thousands of years to address the causes of inflammation, ageing and cognitive health. Traditional preparations of olive include olive oil and olive leaf extract, which are major components of diets that contribute to maintaining cognitive function and reducing neurodegenerative disease risk. Aims of the study: This systematic review aimed to synthesise experimental and limited human evidence on olive biophenols in neurodegenerative disease models, identify the most studied compounds, characterise their mechanisms of action, and evaluate key translational barriers. Materials and methods: Following PRISMA 2020 guidelines and registered with PROSPERO (CRD420251252252), primary studies investigating the effects of well-characterised olive biophenols in neurodegenerative relevant in vitro, in vivo, or human models were systematically reviewed. Each study was assessed for its design, experimental model, mechanistic outcomes and reported limitations. Risk of bias was evaluated using validated tools (SYRCLE/OHAT/ToxR) appropriate for preclinical and experimental study designs. Results: Among the 25 studies, 7 (28.0%) examined oleuropein or oleuropein aglycone, 10 (40.0%) focused on hydroxytyrosol or its derivatives, and 9 (36.0%) investigated oleocanthal. Most studies employed in vivo animal models (57.7%), predominantly transgenic mouse models of AD and toxin-induced PD models. Oleuropein-based studies reported inhibition of amyloid-β and α-synuclein aggregation with behavioural improvements. Hydroxytyrosol primarily exerted antioxidant and anti-inflammatory effects with modest cognitive benefits. Oleocanthal showed the most consistent anti-amyloid and anti-tau activity, including enhanced amyloid-β clearance across the blood–brain barrier. Most studies show a moderate risk of bias due to incomplete reporting, randomisation and blinding. Conclusions: Olive biophenols demonstrate consistent neuroprotective effects in preclinical models; however, translation to clinical application remains limited by pharmacokinetic constraints, methodological heterogeneity, and insufficient human evidence. Full article

Adult neurogenesis, the process of generating new, functional neurons in the mature central nervous system, represents a key mechanism of brain plasticity and a potential source of regeneration. This process occurs primarily within specialised neurogenic niches: the subgranular zone of the hippocampal dentate gyrus (SGZ) and the subependymal zone (SEZ). It is regulated by a complex network of endogenous factors (e.g., hormones, neurotrophins, growth factors) and exogenous factors (environment, stress, diet, physical activity). Impairments in neurogenesis are linked to the pathogenesis of neurodegenerative diseases, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD). In their course, chronic inflammation, mitochondrial dysfunction, oxidative stress, and the accumulation of pathological proteins (β-amyloid, Tau protein, α-synuclein) create a microenvironment that inhibits the proliferation, differentiation, and survival of new neurons. This results in the exacerbation of cognitive and memory deficits. A review of the literature indicates that modulating neurogenesis through non-pharmacological interventions (e.g., a diet rich in anti-inflammatory compounds, physical exercise) and targeted therapeutic strategies represents a promising, albeit complex, research avenue. The primary challenge remains not only stimulating neuron generation but also ensuring their proper maturation, survival, and functional integration into existing neuronal circuits. A deeper understanding of the molecular and environmental mechanisms regulating adult neurogenesis may open new therapeutic possibilities for slowing the progression of neurodegenerative diseases. Full article