Search Results (238)

The aggregation of α-synuclein (αSyn) is a central feature of Parkinson’s disease (PD) and other synucleinopathies. The efficient clearance of αSyn depends largely on the autophagy–lysosomal pathway. Emerging genetic evidence highlights the role of pleckstrin homology and RUN domain-containing M1 protein (PLEKHM1), a critical regulator of autophagosome–lysosome fusion, in the pathogenesis of multiple neurodegenerative diseases. This study investigates the possible effects of increased PLEKHM1 expression on αSyn pathology and neurodegeneration in mice. We utilized a mouse model of PD that is based on A53T-αSyn overexpression, achieved by the stereotactic injection of recombinant adeno-associated viral vectors (rAAV) into the substantia nigra. Additionally, this study explores the effect of PLEKHM1 overexpression on the autophagy–lysosomal pathway under physiological conditions, using transgenic autophagy reporter mice. PLEKHM1 overexpression facilitated the αSyn-induced degeneration of dopaminergic somata in the substantia nigra and degeneration of dopaminergic axon terminals in the striatum. In concert with αSyn expression, PLEKHM1 also potentiated microglial activation. The extent of αSyn pathology, as reported by staining for phosphorylated αSyn, was not affected by PLEKHM1. Using RFP-EGFP-LC3 autophagy reporter mice, rAAV-mediated PLEKHM1 overexpression reduced lysosomal and autolysosomal area, increased LAMP1-LC3 colocalization, and decreased the autolysosome-to-autophagosome ratio. Concurrently, PLEKHM1 overexpression in both genotypes caused p62 accumulation, accompanied by reduced overlap with lysosomal and autophagosomal markers but increased colocalization with autolysosomal markers, indicating impaired cargo degradation during late-stage autophagy. Taken together, elevated PLEKHM1 levels exacerbate neurodegeneration in αSyn-overexpressing mice, possibly by impairing autophagic flux. Now, with in vivo evidence complementing genetic data, alterations in PLEKHM1 expression appear to compromise autophagy, potentially enhancing neuronal vulnerability to secondary insults like αSyn pathology. Full article

Parkinson’s disease (PD) is characterized by the loss of dopaminergic neurons in the substantia nigra and the presence of α-synuclein-positive inclusions known as Lewy bodies. Synphilin-1 is a protein of unknown function that interacts with α-synuclein and has been shown to exhibit cytoprotective effects in both in vitro and in vivo models. In this study, we investigated whether synphilin-1 is phosphorylated by pathological CDK5 and explored the consequences of this modification. Pathological activation of CDK5 occurs mainly through its association with the calpain-cleaved protein p25. Although CDK5 inhibition protects against neurodegeneration in pharmacological PD models, we now show that p25 levels are increased in PD brains. Furthermore, we demonstrate that CDK5, in conjunction with p25, directly phosphorylates synphilin-1, mainly at serine 566. This phosphorylation reduces synphilin-1′s interaction with SIAH1, leading to reduced ubiquitination and subsequent accumulation. We also observed that CDK5-phosphorylated synphilin-1 exhibits a reduced ability to interact with PINK1 and to promote basal levels of mitophagy. Consistent with these findings, the phosphorylation-mimicking synphilin-1 S566E shows decreased translocation to mitochondria, and synphilin-1 levels are reduced in the mitochondria of PD brains compared to age-matched controls. Finally, synphilin-1 S566E promotes retraction of neuronal processes. Taken together, our results suggest that phosphorylation by CDK5 disrupts synphilin-1′s interactions with its protein partners, rendering it more toxic and impairing its ability to support mitophagy and maintain neuronal process homeostasis. We hypothesize that phosphorylation of synphilin-1 by CDK5 may contribute to the pathogenesis of PD. Full article

Allicin (ALC), a naturally occurring organosulfur compound derived from garlic (Allium sativum), exhibits potential neuroprotective properties. Parkinson’s disease (PD) is a progressive neurodegenerative disease characterized by degeneration of dopaminergic neurons and motor dysfunction. This study utilized bioinformatics and network pharmacology methods to predict the anti-PD mechanism of ALC and established in vivo and in vitro PD models using 6-hydroxydopamine (6-OHDA) for experimental verification. Network pharmacological analysis indicates that apoptosis regulation and the PKA/p-CREB/BDNF signaling pathway are closely related to the anti-PD effect of ALC, and protein kinase A (PKA) and dopamine transporter (DAT) are key molecular targets. The experimental results show that ALC administration can alleviate the cytotoxicity of SH-SY5Y induced by 6-OHDA and simultaneously improve the motor dysfunction and dopaminergic neuron loss in PD mice. In addition, ALC can also activate the PKA/p-CREB/BDNF signaling pathway and increase the DAT level in brain tissue, regulate the expression of BAX and Bcl-2, and reduce neuronal apoptosis. These results indicate that ALC can exert anti-PD effects by up-regulating the PKA/p-CREB/BDNF/DAT signaling pathway and inhibiting neuronal apoptosis, providing theoretical support for the application of ALC in PD. Full article

Parkinson’s disease (PD) is a common neurodegenerative disorder with substantial global impact. Although current therapies can provide symptomatic relief, they are often associated with high costs and adverse effects. Natural compounds with a history of traditional medicinal use have emerged as promising alternatives. In this study, we investigated the therapeutic potential and underlying mechanisms of berberine in both cellular and animal models of PD. In vitro, SH-SY5Y cells exposed to 6-hydroxydopamine (6-OHDA) exhibited decreased viability and increased oxidative stress, both of which were significantly alleviated by berberine treatment based on cell viability assays and DCFH-DA staining. Western blot analysis revealed that berberine modulated the AMPK–PGC-1α–SIRT1 signaling pathway and restored the expression of autophagy-related proteins LC3B and P62, suggesting that berberine could improve mitochondrial function and autophagy balance. In vivo studies using a 6-OHDA-induced PD mouse model further confirmed these effects, showing that berberine could improve motor function and lead to molecular changes consistent with in vitro studies. Additionally, safety evaluations indicated no significant hepatotoxicity based on AST and ALT levels. Body weight also remained stable throughout treatment. Collectively, our findings suggest that berberine can not only alleviate PD-related symptoms but also target key pathological mechanisms, supporting its potential as a therapeutic candidate for PD and other neurodegenerative diseases. Full article

Some studies performed in our laboratory on pyrrole and its derivatives pointed towards the enrichment of the evaluations of these promising chemical structures for the potential treatment of neurodegenerative conditions in general and Parkinson’s disease in particular. A classical Paal-Knorr cyclization approach is applied to synthesize the basic hydrazine used for the formation of the designed series of hydrazones (15a–15g). The potential neurotoxic and neuroprotective effects of the newly synthesized derivatives were investigated in vitro using different models of induced oxidative stress at three subcellular levels (rat brain synaptosomes, mitochondria, and microsomes). The results identified as the least neurotoxic molecules, 15a, 15d, and 15f applied at a concentration of 100 µM to the isolated fractions. In addition, the highest statistically significant neuroprotection was observed for 15a and 15d at a concentration of 100 µM using three different injury models on subcellular fractions, including 6-hydroxydopamine in rat brain synaptosomes, tert-butyl hydroperoxide in brain mitochondria, and non-enzyme-induced lipid peroxidation in brain microsomes. The hMAOA/MAOB inhibitory activity of the new compounds was studied at a concentration of 1 µM. The lack of a statistically significant hMAOA inhibitory effect was observed for all tested compounds, except for 15f, which showed 40% inhibitory activity. The most prominent statistically significant hMAOB inhibitory effect was determined for 15a, 15d, and 15f, comparable to that of selegiline. The corresponding selectivity index defined 15f as a non-selective MAO inhibitor and all other new hydrazones as selective hMAOB inhibitors, with 15d indicating the highest selectivity index of >471. The most active and least toxic representative (15d) was evaluated in vivo on Rotenone based model of Parkinson’s disease. The results revealed no microscopically visible alterations in the ganglion and glial cells in the animals treated with rotenone in combination with 15d. Full article

Background: Methylene blue (MB), a versatile redox agent, is emerging as a promising therapeutic in diseases associated with mitochondrial dysfunction. Its ability to optimize the electron transport chain increases ATP synthesis (30–40%) and reduces oxidative stress, protecting cellular components such as mitochondrial DNA. The protective role of this compound has been described in several neurodegenerative disease such as Alzheimer’s and Parkinson’s diseases. However, its role in cardiovascular disease has been poorly explored. Methods: In this study, we explored the impact of MB on murine (HL1) and human (AC16) cardiomyocyte redox signaling and cellular survival using RT-Qpcr analysis and immunochemistry assays. Results: Our results revealed that MB increased functional mitochondria, reversed H₂O₂-induced oxidative damage, and modulated antioxidant gene expression. Furthermore, it regulated the microRNA16–UPR signaling axis, reducing CHOP expression and promoting cell survival. Conclusions: These findings underscore its potential in cardioprotective therapy; however, its putative use as a drug requires in vivo validation in preclinical animal models. Full article

Parkinson’s disease (PD) is a neurodegenerative disorder marked by the progressive loss of dopaminergic neurons in the nigrostriatal pathway. The dopamine active transporter (DAT), a key protein involved in dopamine reuptake, serves as a selective biomarker for dopaminergic terminals in the striatum. DAT binding has been extensively studied using in vivo imaging techniques such as Single-Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET). To support the design of new radiotracers targeting DAT, we employ Quantitative Structure–Activity Relationship (QSAR) analysis on a structurally diverse dataset composed of 57 compounds with known affinity constants for DAT. The best-performing QSAR model includes four molecular descriptors and demonstrates robust statistical performance: R² = 0.7554, Q²_LOO = 0.6800, and external R² = 0.7090. These values indicate strong predictive capability and model stability. The predicted compounds are evaluated using a docking methodology to check the correct coupling and interactions with the DAT. The proposed approach—combining QSAR modeling and docking—offers a valuable strategy for screening and optimizing potential PET/SPECT radiotracers, ultimately aiding in the neuroimaging and early diagnosis of Parkinson’s disease. Full article

Zebrafish (Danio rerio) combine accessible behavioral phenotypes with conserved neurochemical pathways and molecular features of vertebrate brain function, positioning them as a powerful model for investigating early neurodegenerative processes and screening neuroprotective strategies. In this context, integrated behavioral and proteomic analyses provide valuable insights into the initial pathophysiological events shared by conditions such as Parkinson’s disease and related disorders—including mitochondrial dysfunction, oxidative stress, and synaptic impairment—which emerge before overt neuronal loss and offer a crucial window to understand disease progression and evaluate therapeutic candidates prior to irreversible damage. To investigate this early window of dysfunction, zebrafish larvae were exposed to 500 μM 1-methyl-4-phenylpyridinium (MPP⁺) from 1 to 5 days post-fertilization and evaluated through integrated behavioral and label-free proteomic analyses. MPP⁺-treated larvae exhibited hypokinesia, characterized by significantly reduced total distance traveled, fewer movement bursts, prolonged immobility, and a near-complete absence of light-evoked responses—mirroring features of early Parkinsonian-like motor dysfunction. Label-free proteomic profiling revealed 40 differentially expressed proteins related to mitochondrial metabolism, redox regulation, proteasomal activity, and synaptic organization. Enrichment analysis indicated broad molecular alterations, including pathways such as mitochondrial translation and vesicle-mediated transport. A focused subset of Parkinsonism-related proteins—such as DJ-1 (PARK7), succinate dehydrogenase (SDHA), and multiple 26S proteasome subunits—exhibited coordinated dysregulation, as visualized through protein–protein interaction mapping. The upregulation of proteasome components and antioxidant proteins suggests an early-stage stress response, while the downregulation of mitochondrial enzymes and synaptic regulators reflects canonical PD-related neurodegeneration. Together, these findings provide a comprehensive functional and molecular characterization of MPP⁺-induced neurotoxicity in zebrafish larvae, supporting its use as a relevant in vivo system to investigate early-stage Parkinson’s disease mechanisms and shared neurodegenerative pathways, as well as for screening candidate therapeutics in a developmentally responsive context. Full article

Parkinson’s disease (PD) is the second most prevalent neurodegenerative disease. It is characterized by mitochondrial dysfunction, increased reactive oxygen species (ROS), α-synuclein (α-syn) and phosphorylated-tau protein (p-tau) aggregation, and dopaminergic neuron cell death. Current drug therapies only provide temporary symptomatic relief and fail to stop or reverse disease progression due to the severe side effects or the blood–brain barrier. This study aimed to investigate the neuroprotective effects of an intermittent heating approach, thermal cycling-hyperthermia (TC-HT), in an in vitro PD model using rotenone (ROT)-induced human neural SH-SY5Y cells. Our results revealed that TC-HT pretreatment conferred neuroprotective effects in the ROT-induced in vitro PD model using human SH-SY5Y neuronal cells, including reducing ROT-induced mitochondrial apoptosis and ROS accumulation in SH-SY5Y cells. In addition, TC-HT also inhibited the expression of α-syn and p-tau through heat-activated pathways associated with sirtuin 1 (SIRT1) and heat-shock protein 70 (Hsp70), involved in protein chaperoning, and resulted in the phosphorylation of Akt and glycogen synthase kinase-3β (GSK-3β), which inhibit p-tau formation. These findings underscore the potential of TC-HT as an effective treatment for PD in vitro, supporting its further investigation in in vivo models with focused ultrasound (FUS) as a feasible heat-delivery approach. Full article

Pathological aggregation of α-synuclein (αS) is implicated in the pathogenesis of Parkinson’s disease (PD) and other α-synucleinopathies. The current view is that neuron-to-neuron spreading of αS pathology contributes to the progression of α-synucleinopathy. We used an A53T mutant human αS transgenic mouse model (TgA53T) to examine whether the site of pathogenic αS inoculation affects the pattern of neuropathology and whether soluble and insoluble fractions derived from crude pathogenic tissue lysates exhibit differential capacities to initiate αS pathology. To test whether the inoculation site impacts the ultimate spatial/temporal patterns of αS pathology, αS preformed fibrils (PFFs), or brain homogenates from TgA53T mice with α-synucleinopathy, were injected into the cortex/striatum, brainstem, or skeletal muscle. In all cases, inoculation of pathogenic αS induced end-stage motor dysfunction within ~100 days post-inoculation (dpi). Significantly, irrespective of the inoculation sites, the ultimate distribution of the αS pathology was like that seen in normally aged TgA53T mice at end-stage, indicating that the intrinsic neuronal vulnerability is a significant determinant in the induction of αS pathology, even when initiated by inoculation of pathogenic αS. Temporal analysis of brainstem-injected TgA53T mice show that initial αS pathology was seen by 30 days post-inoculation and inflammatory changes occur at later stages. In addition, we show that both highly soluble (S150) and insoluble (P150) fractions from end-stage TgA53T mice can seed de novo αS pathology in vivo. Moreover, the endoplasmic reticulum (ER)-enriched fraction from the TgA53T mice were highly pathogenic as the ER fraction induced αS pathology faster than other fractions when injected unilaterally into TgA53T mice. Our results suggest that multiple αS species from the brain can initiate the development of progressive αS pathology. Full article

Although approached through many concepts, the pleiotropic healing issue, specifically, maintaining/reestablishing tissue integrity, remains a central challenge in pharmacology, particularly when the process is misdirected or not properly controlled. Robert and Szabo’s concept of cytoprotection holds that innate cell (epithelial (Robert), endothelial (Szabo)) integrity and protection/maintenance/reestablishment in the stomach is translated to other organ therapy (cytoprotection → organoprotection) via the cytoprotection agent’s effect. Therefore, we defend stable gastric pentadecapeptide BPC 157 therapy’s efficacy and pleiotropic beneficial effects, along with its high safety (LD1 not achieved), against speculation of its negative impact, speculation of angiogenesis toward tumorigenesis, increased NO and eNOS, damaging free radical formation, and neurodegenerative diseases (Parkinson’s disease and Alzheimer’s disease). Contrarily, in wound healing and general healing capabilities, as reviewed, as a cytoprotective agent and native cytoprotection mediator, BPC 157 controls angiogenesis and the NO-system’s healing functions and counteracts the pathological presentation of neurodegenerative diseases in acknowledged animal models (i.e., Parkinson’s disease and Alzheimer’s disease), and it presents prominent anti-tumor potential in vivo and in vitro. BPC 157 resolved cornea transparency maintenance, cornea healing “angiogenic privilege” (vs. angiogenesis/neovascularization/tumorigenesis), and it does not produce corneal neovascularization but rather opposes it. Per Folkman’s concept, it demonstrates an anti-tumor effect in vivo and in vitro. BPC 157 exhibits a distinctive effect on the NO-level (increase vs. decrease), always combined with the counteraction of free radical formation, and, in mice and rats, BPC 157 therapy counteracts Parkinson’s disease-like and Alzheimer’s disease-like disturbances. Thus, BPC 157 therapy means targeting angiogenesis and NO’s cytotoxic and damaging actions but maintaining, promoting, or recovering their essential protective functions. Full article

Parkinson’s disease (PD) is an aging-related neurodegenerative disease characterized by a progressive loss of dopamine (DA)-secreting neurons in the substantia nigra. Most of the currently available treatments attempt to alleviate the disease symptoms by increasing DA transmission in the brain and are associated with unpleasant side effects. Since there are no treatments that modify the course of PD or regenerate DA neurons, identifying therapeutic strategies that slow, stop, or reverse cell death in PD is of critical importance. Here, factors that confer vulnerability of substantia nigra DA neurons to cell death and the primary mechanisms of PD pathogenesis, including cellular senescence, a cellular stress response that elicits a stable cell cycle arrest in mitotic cells and profound phenotypic changes including the implementation of a pro-inflammatory secretome, are reviewed. Additionally, a discussion of the characteristics, mechanisms, and markers of cellular senescence and the development of approaches to target senescent cells, referred to as senotherapeutics, is included. Although the senotherapeutics curcumin, fisetin, GSK-650394, and astragaloside IV had disease-modifying effects in in vitro and in vivo models of PD, the potential long-term side effects of these compounds remain unclear. It remains to be elucidated whether their beneficial effects will translate to non-human primate models and/or human PD patients. The enhanced selectivity, safety, and/or efficacy of next generation senotherapeutic strategies including senolytic peptides, senoreverters, proteolysis-targeting chimeras, pro-drugs, immunotherapy, and nanoparticles will also be reviewed. Although these next generation senotherapeutics may have advantages, none have been tried in models of PD. Full article

Parkinson’s disease and related synucleinopathies, including dementia with Lewy bodies and multiple system atrophy, are characterised by the pathological aggregation of the α-synuclein (aSyn) protein in neuronal and glial cells, leading to cellular dysfunction and neurodegeneration. This review synthesizes knowledge of aSyn biology, including its structure, aggregation mechanisms, cellular interactions, and systemic influences. We highlight the structural diversity of aSyn aggregates, ranging from oligomers to fibrils, their strain-like properties, and their prion-like propagation. While the role of prion-like mechanisms in disease progression remains a topic of ongoing debate, these processes may contribute to the clinical heterogeneity of synucleinopathies. Dysregulation of protein clearance pathways, including chaperone-mediated autophagy and the ubiquitin–proteasome system, exacerbates aSyn accumulation, while post-translational modifications influence its toxicity and aggregation propensity. Emerging evidence suggests that immune responses and alterations in the gut microbiome are key modulators of aSyn pathology, linking peripheral processes—particularly those of intestinal origin—to central neurodegeneration. Advances in biomarker development, such as cerebrospinal fluid assays, post-translationally modified aSyn, and real-time quaking-induced conversion technology, hold promise for early diagnosis and disease monitoring. Furthermore, positron emission tomography imaging and conformation-specific antibodies offer innovative tools for visualising and targeting aSyn pathology in vivo. Despite significant progress, challenges remain in accurately modelling human synucleinopathies, as existing animal and cellular models capture only specific aspects of the disease. This review underscores the need for more reliable aSyn biomarkers to facilitate the development of effective treatments. Achieving this goal requires an interdisciplinary approach integrating genetic, epigenetic, and environmental insights. Full article

Neurodegenerative diseases are characterised by the progressive loss of neurons, leading to a decline in specific brain functions. Alzheimer’s disease (AD) and Parkinson’s disease (PD) are the most prevalent, affecting approximately 60 million people worldwide. The pathogenesis of these diseases is complex, combining inflammatory, oxidative, and excitotoxic processes that result in neuronal dysfunction and death. Despite recent advances, there is currently no cure for AD and PD. Available therapies demonstrate limited efficacy, highlighting the continuing need for novel therapeutic approaches. Ergolide, a naturally occurring sesquiterpene lactone from the Inula brittanica plant, has shown immunoregulatory properties in systemic immune cells and potential applications in certain cancers. This study examines whether the therapeutic effects of ergolide extend to the brain. We explored its mechanisms of action in vitro, and its capacity to restore behavioural integrity in zebrafish models of inflammation and neurotoxicity in vivo. We report the ability of ergolide to attenuate inflammatory cytokine and nitric oxide (NO) production from microglia in response to toll-like receptor activation. We further propose a role for the NFκB and cysteinyl leukotriene (CysLT) pathways in ergolide-mediated regulation of microglial activation. Ergolide did not protect against oxidative-induced neuronal death in vitro or mitigate seizure activity in zebrafish. Instead, we revealed a pro-oxidant and cytotoxic effect on neuroblastoma cells. Importantly, ergolide improved survival and alleviated the dysfunction in sensorimotor behaviour in a zebrafish model of inflammation. Our findings reveal a neuroprotective effect of ergolide, likely stemming from its immunoregulatory capacity. We also support further investigation of the CysLT pathway as a therapeutic target for neuroinflammatory-related disease. Full article

Background/Objectives: Parkinson’s disease (PD) is a common neurodegenerative disease characterized by motor symptoms caused by the loss of dopaminergic neurons. While the pathophysiology of PD is still not fully understood, it is recognized that oxidative stress plays a major role in its progression. Previous studies have shown that the aerial parts of Artemisia iwayomogi Kitamura (AIK) possess medicinal properties, including antioxidant activity. This study aimed to investigate whether AIK can alleviate neuronal loss and motor symptoms in a PD model and to explore its therapeutic mechanisms. Methods: For the in vitro study, PC12 cells were treated with AIK and 1-methyl-4-phenylpyridinium (MPP⁺). For the in vivo study, C57BL/6J mice were orally administered AIK for 12 days; they received intraperitoneal injections of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) for 5 consecutive days, starting on the 8th day of AIK administration. Results: AIK treatment to PC12 cells in the presence of MPP⁺ enhanced the phosphorylation of the protein kinase B/glycogen synthase kinase-3β signaling pathway, which is a crucial regulator of nuclear factor erythroid 2-related factor 2 (Nrf2) translocation. Additionally, AIK treatment increased cell survival and induced an antioxidant response involving heme oxygenase-1, via increasing the level of Nrf2 in the nucleus. In an MPTP-induced mouse model of PD, AIK administration activated Nrf2 in dopaminergic neurons and prevented the loss of dopaminergic neurons in the brain, which in turn alleviated motor dysfunction. Conclusions: Collectively, these findings suggest that AIK is a potential botanical candidate for PD treatment by protecting dopaminergic neurons through antioxidant activity. Full article