Search Results (1,248)

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by the aggregation of Lewy bodies, composed of the protein α-synuclein, and the degeneration of dopaminergic (DA) neurons in the substantia nigra pars compacta. The management of PD seeks to mitigate motor symptoms by substituting diminished endogenous dopamine; nevertheless, it does not halt disease progression. Various animal models have been employed to elucidate the etiology of PD and to discover disease-modifying treatments. Zebrafish serve as a PD model owing to their capacity for high-throughput screening. This review presents updates on the currently available zebrafish models of PD, encompassing both chemically induced and genetically based models, and discusses their advantages and limitations. This review also delineates numerous investigative strategies that utilize the zebrafish PD model and summarizes the findings of previous studies. Taken together, further studies, including the investigation of the regeneration mechanism of DA neurons, neurobehavioral testing of adult zebrafish reflecting PD-associated neurocognitive impairment, and a reliable gene-based model providing precise gene knockout and reproducibility, may assist in elucidating the critical pathways that trigger PD and its progression, alongside potential targets to hinder this progression. Full article

Parkinson’s disease (PD) is pathologically characterized by the abnormal aggregation of α-synuclein and the progressive loss of dopaminergic neurons, with microglia-mediated neuroinflammation acting as a pivotal driver of pathogenesis. Ferroptosis, an iron-dependent form of regulated cell death, significantly contributes to PD progression. However, the precise mechanisms governing microglial ferroptosis under α-synuclein pathology, particularly the regulatory role of the master antioxidant transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), remain elusive. Here, we employed an in vitro BV2 microglial model and an in vivo A53T transgenic mouse model to elucidate the regulatory effects and underlying mechanisms of Nrf2 on ferroptosis-associated phenotypes induced by α-synuclein pre-formed fibrils (PFFs). In vitro, PFF treatment significantly downregulated microglial Nrf2 expression, triggering ferroptosis-associated phenotypes characterized by reactive oxygen species (ROS) accumulation, ferrous iron (Fe²⁺) overload, and elevated lipid peroxidation. Genetic knockdown of Nrf2 exacerbated these ferroptosis-associated phenotypes and accelerated α-synuclein aggregation. Conversely, Nrf2 overexpression or pharmacological activation via dimethyl fumarate (DMF) profoundly suppressed α-synuclein pathology and mitigated ferroptosis-associated signatures. In vivo, microglial activation in the substantia nigra of PD mice was accompanied by marked Nrf2 downregulation. Strikingly, microglia-specific Nrf2 overexpression significantly reversed motor and non-motor deficits (including olfactory and locomotor impairments), demonstrating the sufficiency of microglial protection. Furthermore, systemic administration of the Nrf2 activator DMF not only ameliorated motor dysfunction but also concurrently rescued nigral dopaminergic neurons and reduced striatal α-synuclein aggregation. Taken together, our findings identify Nrf2 downregulation-driven microglial ferroptosis-associated phenotypes as a critical pathogenic mechanism, and demonstrate that targeting this pathway in vivo ameliorates motor and non-motor deficits while preserving dopaminergic neurons in PD mice. These findings support further research on Nrf2 activation and DMF as potential therapeutic strategies for PD. Full article

Parkinson’s disease (PD) is a neurodegenerative disorder of the central nervous system with a complex pathogenesis. Current conventional medicines are predominantly symptomatic treatments, which fail to reverse neuronal degeneration and often induce severe motor complications following long-term administration. In this context, the advantages of the multi-target holistic regulation provided by traditional Chinese medicine have become increasingly prominent. As the core active ingredients of Panax ginseng, ginsenosides can penetrate the blood–brain barrier and exhibit broad neuroprotective prospects in PD treatment. This article systematically reviews the neuroprotective mechanisms of different configurations of ginsenosides—mainly including protopanaxadiol (PPD) and protopanaxatriol (PPT) saponins—against PD. Studies indicate that PPD-type saponins (e.g., Rb1, Rg3, Rd) excel in directly inhibiting the abnormal aggregation of α-synuclein (α-syn), reducing oxidative stress, and preventing neuronal apoptosis. Conversely, PPT-type saponins (e.g., Rg1, Re) demonstrate significant advantages in suppressing microglia-mediated neuroinflammation, improving mitophagy, and regulating lipid metabolism networks. Furthermore, this review highlights a novel intervention strategy utilizing ginsenosides based on antioxidation and iron metabolism regulation. By maintaining the homeostasis of iron transport proteins such as DMT1 (Divalent Metal Transporter 1) and FPN1 (Ferroportin 1), and activating the Nrf2/xCT/GPX4 signaling axis, these compounds effectively block the vicious cycle of “iron deposition-oxidative stress-lipid peroxidation (LPO),” thereby inhibiting ferroptosis in dopaminergic neurons. In summary, structurally diverse ginsenosides exhibit distinct characteristics in targeting the core pathological events of PD. The scientific combination of ginsenoside monomers with different mechanisms in the future holds promise for constructing a comprehensive multi-target neuroprotective network, providing a solid theoretical foundation for novel ginsenoside-based combination therapies against PD. Full article

This study aimed to identify candidate molecular pathways mediating dopaminergic dysfunction induced by PFAS mixture exposure, with a focus on the TM/5-HT signaling axis and calcium-linked lipid metabolites, and to explore potential gut-brain axis involvement. Adult mice were exposed to a PFAS mixture. Behavioral tests assessed spatial memory, spontaneous activity, and motor coordination. Histopathological and ultrastructural analyses examined neuronal atrophy, mitochondrial damage, α-synuclein (α-syn), and tyrosine hydroxylase (TH). Transcriptomics, metabolomics, and gut microbiota profiling (16S rRNA sequencing) were performed, followed by integrated multi-omics and correlation analyses. PFAS exposure was associated with PD-relevant motor and cognitive impairments, including impaired spatial memory, reduced spontaneous activity, and motor coordination deficits. Neuronal atrophy, mitochondrial structural damage, upregulation of α-syn, and downregulation of TH were observed. Transcriptomics identified 315 differentially expressed genes (DEGs) enriched in ciliary movement, neuroactive ligand-receptor interactions, and serotonergic synapses. Metabolomics identified 130 differentially abundant metabolites involved in arachidonic acid metabolism and serotonergic synapses. Integrated analysis highlighted correlative changes in the TM/5-HT signaling pathway. Phosphatidylinositol PI(16:0/20:2(11Z,14Z)) showed a strong positive correlation with Dbh gene expression, suggesting a candidate association between Dbh expression and phosphatidylinositol alterations. Gut microbiota analysis revealed compositional alterations (e.g., Muribaculaceae, Ileibacterium) and predicted functional shifts (e.g., tryptophan metabolism–related modules) were observed; these findings are exploratory. This study identifies multi-omics signatures associated with PFAS mixture-induced dopaminergic dysfunction in mice. The TM/5-HT pathway emerges as a candidate molecular axis requiring further investigation. Gut microbiota alterations suggest a potential peripheral component, but causality and gut-brain axis involvement remain hypothetical and need direct experimental validation. Full article

The relationship between stress and Parkinson’s disease is regarded as complex and multifaceted, although a direct causal link has not yet been conclusively proven. One prevailing hypothesis is based on the activation of the hypothalamic–pituitary–adrenal (HPA) axis and the consequent elevation of glucocorticoid levels. Prolonged exposure to these hormones may exacerbate oxidative stress, thereby rendering the dopaminergic neurons within the brain’s subcortical structures more susceptible to degeneration. Furthermore, stress may intensify neuroinflammation through the activation of microglia—a mechanism that could constitute a significant factor in the pathogenesis of Parkinson’s disease. Another important concept concerns the direct interaction of stressors with the dopaminergic system. Physiological and psychological stress can alter dopaminergic transmission by affecting both the synthesis and release of dopamine, as well as the sensitivity of dopamine receptors. Severe or chronic stress may contribute to the disruption of dopaminergic mechanisms and accelerate the onset of clinical symptoms in predisposed individuals. Furthermore, many researchers draw attention to the role of stress-induced aggregation of α-synuclein—a key protein implicated in the pathogenesis of Parkinson’s disease. Clinical data suggest a highly probable link between post-traumatic stress disorder and an increased risk of developing Parkinson’s disease, although these findings remain inconclusive. It is possible that stress acts not as a primary cause, but rather as a modifying factor that interacts with genetic predisposition, accelerating or triggering neurodegenerative processes. The aim of our narrative review was to examine these concepts and discuss possible directions for future research into the interaction between stress and Parkinson’s disease. Full article

At present, there is still a lack of effective treatments to slow the progression of Parkinson’s disease. Naturally derived active substances, valued for their safety and multi-target potential, have become an important direction in anti-PD drug development, with marine organisms representing a valuable source of bioactive peptides. This study aimed to isolate and identify anti-PD peptides from Rapana venosa protein hydrolysates. Through bioactivity-guided screening combined with an MPTP-induced zebrafish PD model, three novel active peptides—KSTELLI, FLVKLPMFM, and SDSLSEILIS—were successfully identified. The study showed that these peptides significantly alleviated dopaminergic neuron loss, improved the cerebral vascular system, restored motor and sensory function, and alleviated oxidative stress. Molecular docking confirmed their stable binding to key PD targets (DDC, α-synuclein, and MAO-B). Further transcriptomic and gene expression analyses revealed that their neuroprotective effects involve the regulation of pathways related to metabolism, oxidative stress, inflammation, and apoptosis, with the three peptides exhibiting distinct mechanistic emphases. The research demonstrates that these marine-derived peptides exert neuroprotective effects through a synergistic multi-target mechanism, laying a foundation for the development of novel lead compounds against Parkinson’s disease. Full article

Background/Objectives: Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by dopaminergic neuronal loss, oxidative stress, and mitochondrial dysfunction. Although levodopa (L-Dopa) remains the main symptomatic treatment, prolonged administration can lead to adverse effects. Safranal, a bioactive constituent of Crocus sativus, has antioxidant and anti-apoptotic properties. This study evaluated the neuroprotective potential of L-Dopa and safranal, individually and in combination, in an in vitro cell-culture PD model. Methods: SH-SY5Y human neuroblastoma cells were treated with 6-hydroxydopamine (6-OHDA, 50 µM) to induce cytotoxicity. Cells were pretreated with L-Dopa (5–500 µM) and safranal (1–500 µM and 1–5 mM) for 4 or 24 h. Cell viability was assessed using 3-(4, 5-dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. Mitochondrial membrane potential (MMP), caspase-3/7 activity, and autophagy markers were also evaluated. Synergy was analyzed using Combination Index (CI) analysis. Furthermore, mRNA levels of circadian rhythm associated genes were also evaluated. Results: 6-OHDA significantly impaired cell viability and mitochondrial function. Pretreatment with low doses of L-Dopa and safranal partially improved cell viability and reduced apoptosis and showed a tendency to decrease autophagy-associated marker levels. Higher L-Dopa concentrations caused mild cytotoxicity, while high-dose safranal exhibited pronounced concentration-dependent toxicity. CI analysis confirmed synergistic interaction between both drugs in mitigating 6-OHDA-induced toxicity. Combined treatment markedly improved cell survival preserved mitochondrial function, and reduced caspase-3/7 activity compared with monotherapy. A significant increase in the mRNA levels of Per1, Clock, Bmal1 and Cry1 genes was observed in groups treated with L-Dopa and safranal together. Conclusions: L-Dopa and safranal exerted concentration-dependent neuroprotective effects in SH-SY5Y cells. Their combination enhanced cytoprotection, which was associated with modulation of mitochondrial function, oxidative stress, apoptosis, and autophagy-related responses. Full article

Parkinson’s disease (PD) is a prevalent neurodegenerative disorder, characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta and the accumulation of Lewy bodies. Over recent decades, various cellular mechanisms underlying PD have been elucidated, including autophagy, mitochondrial dysfunction, neuroinflammation, and axonal transport. Among them, axonal transport plays a critical role in maintaining the dynamic homeostasis of proteins, membrane-bound organelles, and cellular metabolism within neurons. Unfortunately, a comprehensive overview of axonal transport in PD remains absent. In this review, we synthesized the current literature on axonal transport in PD, leveraging neurotoxic and genetic models to explore the causes and consequences of axonal transport alterations in PD. Through this summary, we aim to deepen our understanding of PD pathogenesis and provide potential therapeutic targets for intervention. Full article

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in which dopaminergic dysfunction plays a central role. Beyond its neurotransmitter function, dopamine is a redox-active molecule capable of generating reactive oxygen species and toxic intermediates, particularly when cytosolic dopamine accumulates because of altered vesicular storage or transporter imbalance. This review examines whether dopamine-derived oxidative stress may represent a biologically plausible and testable framework for ADHD by integrating current evidence on dopamine metabolism, oxidative stress, and neuronal dysfunction, while distinguishing direct evidence from indirect and translational findings. A structured literature search was conducted in PubMed, Scopus, and Web of Science for relevant English-language studies published between January 2000 and March 2026. The available evidence suggests that dopamine-derived oxidative stress may help link disturbed dopamine handling to protein modification, lipid peroxidation, mitochondrial dysfunction, synaptic inefficiency, and circuit-level abnormalities in ADHD. Although direct in vivo evidence remains limited, this framework may help distinguish dopamine-derived oxidative stress from more general oxidative imbalance in ADHD and may guide future biomarker-based, experimental, and translational research. Full article

Simazine (SIM), a triazine herbicide and potential environmental risk factor, has been associated with neurotoxicity; however, the underlying mechanisms remain poorly characterized. Salidroside (SAL), a natural antioxidant with mitochondrial protective properties, has been reported to alleviate SIM-induced neuronal injury. Using an integrated strategy combining network toxicology and network pharmacology with experimental validation, this study systematically investigated the neurotoxic mechanisms of SIM and the neuroprotective effects of SAL. Bioinformatics analyses revealed that SIM- and SAL-related targets were significantly enriched in apoptosis- and autophagy-associated pathways. In vitro experiments demonstrated that SIM induced mitochondrial structural damage, metabolic dysfunction, and dopaminergic neuron-like SH-SY5Y cells apoptosis by inhibiting PINK1/Parkin-mediated mitophagy. Conversely, SAL effectively protected SH-SY5Y cells against SIM-induced neurotoxicity by restoring PINK1/Parkin signaling, thereby enhancing mitophagy and suppressing apoptosis. The present study elucidates the central mechanism of SIM-induced PD-like neurotoxicity in vitro and, for the first time, confirms the potential protective effect of SAL. These findings provide a novel theoretical basis for investigating nerve injury induced by SIM exposure and underscore the potential of plant-derived compounds in preventing nerve injuries related to environmental toxicants. Full article

Neurodegenerative disorders, including Parkinson’s disease (PD), are largely treated with symptomatic therapies, underscoring the need for strategies that target underlying disease mechanisms. Glucagon-like peptide-1 (GLP-1) and its receptor (GLP-1R), a class B G protein-coupled receptor best known for metabolic regulation, have attracted interest due to the increasing evidence of central nervous system (CNS) actions. This review synthesises mechanistic, preclinical, and clinical evidence examining GLP-1R signalling in PD and related neurodegenerative contexts. We integrate findings from cellular and animal models with early-phase clinical studies of GLP-1 receptor agonists (GLP-1RAs). Across experimental systems, GLP-1R activation engages conserved intracellular pathways—cAMP/PKA, PI3K/Akt, and ERK—that regulate mitochondrial function, oxidative stress, autophagy-lysosomal dynamics, and inflammatory signalling. In PD-relevant models, these pathways intersect with key pathogenic features, including α-synuclein accumulation, dopaminergic neuron vulnerability, and glial reactivity. Clinical studies to date demonstrate acceptable safety and tolerability, alongside biomarker evidence of central pathway engagement and variable effects on motor and non-motor outcomes. However, uncertainties remain regarding CNS target engagement, peripheral versus CNS mechanisms, and disease-stage dependence. Overall, the current evidence positions GLP-1R signalling as a biologically plausible therapeutic pathway in PD that warrants further mechanistic clarification and rigorous evaluation in ongoing and future clinical trials. Full article

Parkinson’s disease (PD) is the second most prevalent neurodegenerative disorder. It is characterized by the accumulation of misfolded α-synuclein (α-syn) and progressive loss of dopaminergic neurons in the substantia nigra. Due to the limitations of current therapies, mesenchymal stromal cell (MSC) transplantation has emerged as a promising neuroprotective strategy. This study evaluated the neuroprotective potential of decidua-derived mesenchymal stromal cells (DMSCs) in vitro using a human neuroblastoma cell line (NB69) exposed to the neurotoxin 1-methyl-4-phenylpyridinium (MPP+) as a PD model. The NB69 cells were differentiated into a mature dopaminergic phenotype using dibutyryl cyclic adenosine monophosphate (dbcAMP) and then exposed to MPP+. In proliferative NB69 cells, the effect of DMSCs was masked by their inherent antitumor activity against the neuroblastoma phenotype. Conversely, in the differentiated NB69 model, DMSCs demonstrated a significant protective role against MPP+-induced cytotoxicity. Interestingly, the mechanism by which DMSCs might exert a neuroprotective effect against MPP+ damage in differentiated NB69 cells appears to involve improving mitochondrial function by reducing free radicals. In summary, these findings suggest that DMSCs exert a neuroprotective effect in a dopaminergic-like context and highlight the importance of using differentiated cell models to accurately evaluate cell-based therapies for PD in the striatum. Full article

This study aimed to investigate the molecular mechanisms underlying dopaminergic injury induced by gestational and lactational atrazine (ATR) exposure in rat offspring, with a particular focus on non-coding RNA-mediated regulation. Pregnant rats were exposed to ATR during gestation and lactation. Offspring underwent behavioral testing at postnatal day 21 (PND21) and were sacrificed for midbrain tissue collection at PND28. Behavioral alterations, histopathological changes in the substantia nigra, and dopaminergic marker expression were assessed to evaluate ATR-induced neurotoxicity. Whole-transcriptome sequencing was then performed to identify differentially expressed mRNAs, miRNAs, and lncRNAs, followed by co-expression, protein–protein interaction, and competing endogenous RNA (ceRNA) network analyses. Key targets were validated by qRT-PCR. Candidate molecules identified from transcriptomic and ceRNA analyses were further examined in an ATR-induced neurotoxicity model established in RA-differentiated SK-N-SH cells. Dual-luciferase reporter, Ago2-RNA immunoprecipitation, and biotin-labeled RNA pull-down assays were used to examine putative binding relationships and molecular interactions. In addition, lentivirus-mediated Elavl4 overexpression was performed to further evaluate the role of this candidate regulator in ATR-induced Nurr1 downregulation. Gestational and lactational ATR exposure induced significant behavioral abnormalities in rat offspring. These changes were accompanied by histopathological alterations in the substantia nigra, including reduced TH immunoreactivity, as well as abnormal expression of dopaminergic markers, characterized by decreased TH and Nurr1 levels and increased α-syn expression. Together, these findings indicate the presence of dopaminergic injury. Whole-transcriptome analysis further revealed widespread dysregulation of mRNAs, miRNAs, and lncRNAs in ATR-exposed offspring. Subsequent integrative analysis suggested a potential ceRNA regulatory relationship among Elavl4, miR-301a-5p, and Nurr1, which was further supported by qRT-PCR. Dual-luciferase reporter, RIP, and RNA pull-down assays supported direct interactions between miR-301a-5p and both Elavl4 and Nurr1, as well as their association with the Ago2-containing silencing complex. Moreover, Elavl4 overexpression partially reversed ATR-induced Nurr1 downregulation in vitro. Gestational and lactational ATR exposure induced behavioral abnormalities and dopaminergic injury in rat offspring. Whole-transcriptome analysis combined with experimental validation suggests a potential association between the Elavl4/miR-301a-5p/Nurr1 ceRNA axis and ATR-induced dopaminergic injury, providing insight into the post-transcriptional mechanisms underlying developmental neurotoxicity. Full article

Progressive supranuclear palsy-Richardson’s syndrome (PSP-RS) is a primary 4R tauopathy in which early axonal dysfunction may precede overt neurodegeneration; however, the mechanisms linking Tau dysregulation to cytoskeletal vulnerability remain poorly defined. Here, we generated induced pluripotent stem cell (iPSC)-derived midbrain dopaminergic neurons from individuals with sporadic PSP-RS and matched healthy controls and performed integrated transcriptomic and proteomic analyses. PSP-RS neurons exhibited coordinated suppression of dopaminergic and synaptic programs alongside activation of cytoskeletal remodeling and stress-related pathways. These changes were accompanied by increased Tau phosphorylation, neurofilament accumulation, and structural alterations of the axonal compartment, consistent with an early axonopathic phenotype. Notably, mechanistic target of rapamycin (mTOR) signaling significantly increased. Pharmacological inhibition of mTOR reduced Tau phosphorylation and neurofilament levels, indicating that mTOR activity contributes to the maintenance of cytoskeletal imbalance. In conclusion, our findings support a model in which early cytoskeletal dysfunction in PSP-RS arises from the convergence of Tau dysregulation, impaired structural homeostasis, and altered signaling pathways. Rather than acting as a primary driver, mTOR appears to function as a pathogenic amplifier that sustains axonal stress. This study provides a human cellular framework to investigate early axonopathic mechanisms in sporadic PSP-RS. Full article

Neurovascular coupling (NVC) maintains appropriate cerebral blood flow (CBF) in response to neuronal activity, and its disturbance, known as neurovascular uncoupling (NVU), is increasingly recognised as a major contributor to neurodegenerative disease. Alzheimer’s disease (AD) NVU is caused by Aβ buildup, tau pathology, endothelial dysfunction, and persistent neuroinflammation, leading to poor CBF control and blood–brain barrier (BBB) disintegration. Parkinson’s disease (PD) is characterised by α-synuclein aggregation, oxidative stress, mitochondrial dysfunction, and dopaminergic neuronal loss, all of which impede cerebrovascular regulation. These disease-specific mechanisms interact via similar vascular pathways, establishing NVU as a critical connection between neuronal degeneration and cerebrovascular dysfunction. This study highlights the critical role of NVU in neurodegeneration by investigating shared and disease-specific processes in AD and PD. Tau pathology disturbs vascular regulation in AD, whereas dopaminergic neuron loss impairs cerebrovascular control in PD. Both Aβ and α-synuclein are linked to endothelial dysfunction and oxidative stress, albeit originating in different pathologies. Comparative analysis reveals distinct vascular abnormalities in each condition, as well as shared processes such as inflammation and BBB disruption. The study also covers developments in biomarker discovery and neuroimaging techniques that allow for exact characterisation of NVU, facilitating early diagnosis and treatments. In addition, lifestyle changes and pharmacological treatments for oxidative stress and endothelial injury are being examined. This study highlights the significance of NVU as a fundamental pathogenic mechanism, underscoring its importance for comprehending disease development and formulating novel therapeutic strategies. Full article