Oxidative stress and regulated cell death in Parkinson's disease

T-type calcium channels attenuate anxiety in MPTP-treated mice through modulating burst firing of dopaminergic neuron

T-type calcium channel(T-VGCC) is a critical voltage-gated channel extensively involved in signal transmission and functional regulation of the nervous system. Recent studies have shown that T-VGCC exhibits low-threshold activation properties and generate high-frequency firing, making it essential in neuronal firing patterns. However, the effects of T-VGCC on dopaminergic (DAergic) neurons in the substantia nigra (SN) remain unclear. In the present study, we constructed Parkinson's disease (PD) model mice using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), and we found that intracerebroventricular injection of T-VGCC blocker (Mibefradil) alleviates the anxiety behavior and the extent of damage to DAergic neurons in MPTP-treated mice. In vivo electrophysiological experiments demonstrated that T-VGCC directly regulates the burst firing of DAergic neurons. Correlation analysis suggested a strong association between DAergic neuron burst firing and anxiety-like behaviors in mice. Notably, calcium imaging experiments revealed that inhibiting T-VGCC significantly decreased calcium signal levels in DAergic neurons of MPTP-treated mice. To sum up, our research results for the first time reveal the crucial role that the burst firing of DAergic neurons in the SN mediated by T-VGCC plays in regulating anxiety behavior in PD. This discovery offers a potential therapeutic target for PD patients with anxiety.

Unraveling the role of the IL-20 cytokine family in neurodegenerative diseases: Mechanisms and therapeutic insights

The IL-20 cytokine family, comprising IL-19, IL-20, IL-22, IL-24, and IL-26, has emerged as a critical player in the pathogenesis of neurodegenerative diseases due to its multiple roles in inflammation, tissue repair, and immune modulation. These cytokines signal through IL-20 receptor complexes (IL-20RA/IL-20RB and IL-22RA1/IL-20RB), triggering diverse immune processes. Recent evidence highlights their significant contributions to neuroinflammation and neurodegeneration in central nervous system disorders. IL-20 family cytokines impact microglial activation, which, when dysregulated, exacerbates neuronal damage. Specifically, IL-20 and IL-24 are linked to elevated pro-inflammatory markers in glial cells, promoting neurodegeneration. In contrast, IL-22 exhibits dual functionality, exerting protective and pathological roles depending on the inflammatory milieu. Key mechanisms involve the regulation of blood-brain barrier integrity, oxidative stress, and autophagy. IL-22 and IL-24 also protect neurons by enhancing antioxidant defenses and maintaining epithelial barrier function, while their dysregulation contributes to blood-brain barrier disruption and protein aggregate accumulation, hallmark features of Alzheimer's disease, Parkinson's disease, and multiple sclerosis. Elevated IL-22 levels in Alzheimer's disease and IL-19's regulatory role in multiple sclerosis suggest they may serve as potential biomarkers and therapeutic targets. IL-26's role in amplifying inflammatory cascades further underscores the complexity of this cytokine family in neurodegenerative pathology. Therapeutically, strategies targeting IL-20 cytokines include monoclonal antibodies, receptor modulation, and recombinant cytokine administration. These approaches aim to mitigate neuroinflammation, restore immune balance, and protect neuronal integrity. This review underscores the IL-20 family's emerging relevance in neurodegenerative diseases, highlighting its potential for novel diagnostic and therapeutic strategies.

Sleep deprivation accelerates Parkinson's disease via modulating gut microbiota associated microglial activation and oxidative stress

The interplay between Parkinson's disease (PD) and sleep disturbances suggests that sleep problems constitute a risk factor for PD progression, but the underlying mechanisms remain unclear. Microglial activation and oxidative stress are considered to play an important role in the pathogenesis of aging and neurodegenerative diseases. We hypothesized that sleep deprivation (SD) could exacerbate PD progression via modulating microglial activation and oxidative stress. To test this hypothesis, we established a PD mouse model using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), then subjected the mice to SD. A battery of behavioral tests, including rotarod, pole, adhesive removal, and open field tests, were used to assess motor function. Our study showed that SD exacerbated motor deficits, loss of tyrosine hydroxylase (TH), microglial activation and oxidative stress damage in PD model mice. Fecal microbiota transplantation experiments revealed that SD mediated PD progression, microglial activation and oxidative stress via the gut microbiota. 16S rRNA sequencing analysis indicated that SD increased the abundances of bacteria such as Bacteroidaceae, while decreasing the abundances of bacteria including Lactobacillus. Non-targeted metabolomic analysis of gut microbiota-derived metabolites revealed that SD significantly increased the production of adenosine (ADO), a purine metabolite. Probiotic supplementation reversed the effects of SD on motor deficits, dopaminergic neuron loss, microglial activation and oxidative stress damage in PD mice; it also decreased SD-induced ADO production. Administration of Adenosine A2A receptor (A2AR) inhibitors, Istradefylline (Ist), attenuated the roles of SD and ADO in promoting microglial activation, oxidative stress and PD progression. Taken together, our findings indicate that SD accelerates PD progression via regulating microbiota associated microglial activation and oxidative stress, suggesting that efforts to improve sleep quality can be used to prevent and treat PD.

Volatile oils of Schisandra chinensis (Turcz.) Baill alleviates Parkinson's disease by activating the Nrf2 pathway to positively regulate autophagy and oxidative stress

Schisandra chinensis (Turcz.) Baill, which is frequently used in health products and drinks, is recognized for its high content of essential oils that could have protective effects against PD, despite the lack of complete understanding of its pharmacological mechanisms. This research aims to examine how ESC can affect autophagy signaling pathways and activate the Nrf2/HO-1 pathway to effectively decrease oxidative damage, thus shedding light on the possible anti-PD effects of this treatment. The results demonstrated that ESC significantly reduced behavioral issues linked to Parkinson's disease in a mouse model that was induced by MPTP and safeguarded dopaminergic neurons that expressed tyrosine hydroxylase. Moreover, ESC boosted the antioxidant capability of Nrf2, assisted with autophagy processes, and finally decreased protein expression levels of Keap1, HO-1, MAPK, mTOR, and ERK. According to in vitro studies, ESC treatment had a significant reduction in H2O2-induced cytotoxicity and oxidative stress levels, which suggests that Nrf2 targets ESC after treatment. The activation of both autophagy and Nrf2 antioxidant pathways was assessed using western blotting. In conclusion, ESC exhibits the potential to suppress oxidative stress by activating Nrf2 in response to autophagy, which is positioned as a promising pharmaceutical candidate, especially for the management and treatment of PD and related disorders.

Natural flavonoids from herbs and nutraceuticals as ferroptosis inhibitors in central nervous system diseases: current preclinical evidence and future perspectives

Flavonoids are a class of important polyphenolic compounds, renowned for their antioxidant properties. However, recent studies have uncovered an additional function of these natural flavonoids: their ability to inhibit ferroptosis. Ferroptosis is a key mechanism driving cell death in central nervous system (CNS) diseases, including both acute injuries and chronic neurodegenerative disorders, characterized by iron overload-induced lipid peroxidation and dysfunction of the antioxidant defense system. This review discusses the therapeutic potential of natural flavonoids from herbs and nutraceuticals as ferroptosis inhibitors in CNS diseases, focusing on their molecular mechanisms, summarizing findings from preclinical animal models, and providing insights for clinical translation. We specifically highlight natural flavonoids such as Baicalin, Baicalein, Chrysin, Vitexin, Galangin, Quercetin, Isoquercetin, Eriodictyol, Proanthocyanidin, (-)-epigallocatechin-3-gallate, Dihydromyricetin, Soybean Isoflavones, Calycosin, Icariside II, and Safflower Yellow, which have shown promising results in animal models of acute CNS injuries, including ischemic stroke, cerebral ischemia-reperfusion injury, intracerebral hemorrhage, subarachnoid hemorrhage, traumatic brain injury, and spinal cord injury. Among these, Baicalin and its precursor Baicalein stand out due to extensive research and favorable outcomes in acute injury models. Mechanistically, these flavonoids not only regulate the Nrf2/ARE pathway and activate GPX4/GSH-related antioxidant pathways but also modulate iron metabolism proteins, thereby alleviating iron overload and inhibiting ferroptosis. While flavonoids show promise as ferroptosis inhibitors for CNS diseases, especially in acute injury settings, further studies are needed to evaluate their efficacy, safety, pharmacokinetics, and blood-brain barrier penetration for clinical application.

Liver fibrosis associated with more severe motor deficits in early Parkinson's disease

OBJECTIVE

To determine the impact of hepatic dysfunction on the motor manifestations of Parkinson's disease.

METHODS

We conducted a retrospective cohort study using data from the Parkinson's Progression Markers Initiative. Liver fibrosis was defined using the Fibrosis-4 score. Our primary outcome was the association of baseline Fibrosis-4 score with the Movement Disorders Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III score. Additional outcomes were MDS-UPDRS part II, MDS-UPDRS part IV, Hoehn and Yahr stage, and levodopa equivalent daily dose. We used linear regression models to evaluate associations at baseline and 5 years after enrollment. We used linear mixed models to evaluate the association of liver fibrosis with the progression of motor dysfunction. Models were adjusted for demographics, comorbidities, alcohol use, time since Parkinson's disease diagnosis, levodopa equivalent daily dose, and genetic predisposition.

RESULTS

We included 360 people with Parkinson's disease with a mean age of 61.8 years (standard deviation 9.7) and 41.1 % women. There was a significant association between liver fibrosis and baseline MDS-UPDRS part III score (β=2.3, 95 % CI: 0.2, 4.5). Liver fibrosis was also correlated with higher interhemispheric signal asymmetry on DAT-SPECT scans in the anterior putamen (p < 0.05 by Wilcoxon rank sum test). There was no correlation with Fibrosis-4 score and any other motor assessment at baseline or after 5 years. Patients with elevated Fibrosis-4 scores had a slower rate of progression in MDS-UPDRS part III scores.

CONCLUSION

In people with Parkinson's disease, the presence of comorbid liver fibrosis was associated with more severe motor dysfunction early, but not later, within their disease course.

New Insights on the Potential Role of Pyroptosis in Parkinson's Neuropathology and Therapeutic Targeting of NLRP3 Inflammasome with Recent Advances in Nanoparticle-Based miRNA Therapeutics

Parkinson's disease (PD) is a widespread neurodegenerative disorder characterized by the gradual degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc). This review aims to summarize the recent advancements in the pathophysiological mechanisms of pyroptosis, mediated by NLRP3 inflammasome, in advancing PD and the anti-pyroptotic agents that target NLRP3 inflammatory pathways and miRNA. PD pathophysiology is primarily linked to the aggregation of α-synuclein, the overproduction of reactive oxygen species (ROS), and the development of neuroinflammation due to microglial activation. Prior research indicated that a significant quantity of microglia is activated in both PD patients and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse models, triggering neuroinflammation and resulting in a cascade of cellular death. Microglia possess an inflammatory complex pathway termed the nucleotide-binding oligomerization domain-, leucine-rich repeat, and pyrin domain-containing 3 (NLRP3) inflammasome. Activation of the NLRP-3 inflammasome results in innate cytokines maturation, including IL-18 and IL-1β, which initiates the neuroinflammatory signal and induces a type of inflammatory cell death known as pyroptosis. Upon neuronal damage, intracellular levels of damage-associated molecular patterns (DAMPs), including reactive oxygen species (ROS), would build. DAMPs induce unregulated cell death and subsequent release of oxidative intermediates and pro-inflammatory cytokines, leading to the progression of PD. Thus, targeting of neuroinflammation using antipyroptotic medications can be efficiently achieved by blocking NLRP3 and obstructing IL-1β signaling and release. Furthermore, many research studies showed that miRNAs have been identified as regulators of the NLRP3 inflammasome and Nrf2 signal, which subsequently modulate the NLRP3-Nrf2 axis in PD. Nanotechnology promises potential for the advancement of miRNA-based therapies. Nanoparticles that ensure miRNA stability, traverse the blood-brain barrier (BBB) and distribute miRNA targeting regions needed to be created. In conclusion, targeting the pyroptosis pathway via NLRP3 or miRNA may serve as a prospective therapeutic strategy for PD in the future.

Enhancing the Oral Bioavailability of Glutathione Using Innovative Analogue Approaches

Background: Glutathione (GSH) is an essential antioxidant that protects against oxidative stress, but its oral bioavailability is below 1% due to enzymatic degradation and poor gastrointestinal absorption. Improving the oral bioavailability of GSH could significantly enhance its therapeutic efficacy. Methods: This study synthesised GSH analogues with chemical modifications to improve bioavailability. Seven GSH derivatives were designed: three analogues with altered stereochemistry (1.62, 1.63, and 1.64) and three N-methylated derivatives (1.65, 1.70, and 1.71), alongside a native GSH (1.61). The analogues were synthesised via Fmoc-solid-phase peptide synthesis, and they were characterised using reverse-phase high-performance liquid chromatography (RP-HPLC), electrospray ionisation mass spectrometry (ESI-MS), Fourier-transform infrared spectroscopy (FTIR), and nuclear magnetic resonance (NMR) spectroscopy. Their toxicity was assessed on Caco-2 cells for viability, and their antioxidant activity was assessed on UVA-irradiated fibroblast cells, enzymatic resistance, and interactions with GSH-metabolising enzymes. Results: Among the tested analogues, the N-methylated cysteine Compound (1.70) emerged as the most promising candidate. Compound 1.70 demonstrated superior resistance to enzymatic degradation, as well as showing enhanced cell viability and improved antioxidant activity. In vivo studies revealed a 16.8-fold increase in plasma half-life (t½) and a 16.1-fold increase in oral bioavailability compared to native GSH. Conclusions: Chemical modification strategies, particularly the N-methylation of GSH, present a viable approach to enhancing oral bioavailability. Compound 1.70 showed significant potential for therapeutic applications, warranting further investigation and development in clinical settings.

Unraveling the Neuropharmacological Properties of Lippia alba: A Scientometric Approach

Lippia alba (Verbenaceae) is popularly known as lemon balm or false melissa and is one of the most widely used plants in traditional medicine in the Amazon region. In this study, we conducted a comprehensive bibliometric analysis, with conventional metrics associated with a critical review based on the neuropharmacological activities, to identify potential medical applications and also gaps in knowledge that require further investigation. Fifty-two articles were included according to the eligibility criteria. In the country analysis, Brazil emerged as the main contributor to research with the highest number of publications and citations. Notably, nine of the ten main research institutions are Brazilian, with the Universidade Federal de Santa Maria standing out with 761 citations. The keywords "anesthesia", "Lippia alba", and "essential oil" were the most frequent, highlighting their importance in this field. Essential oils are the most common type of extraction, which linalool, citral, geraniol, carvone, and limonene were the main constituents identified. According to the type of study, preclinical studies presented the highest frequency, primarily through fish experimental models. The main neuropharmacological activities identified were sedative-anesthetic, anxiolytic, anticonvulsant, and analgesic, with mechanisms of action via the GABAergic pathway. This bibliometric review provided new evidence reinforcing the potential of L. alba as a promising alternative for the treatment of neuropsychiatric disorders. It also highlighted existing knowledge gaps, mainly related to the comparison of the actions of the different chemotypes of the species and the investigation of the mechanisms underlying their neuropharmacological properties. Additionally, there is a lack of knowledge in other emerging areas related to the central nervous system, such as mood and cognitive disorders.

Mitochondria-targeted nanovesicles for ursodeoxycholic acid delivery to combat neurodegeneration by ameliorating mitochondrial dysfunction

Mitochondria are pivotal in sustaining oxidative balance and metabolic activity within neurons. It is well-established that mitochondrial dysfunction constitutes a fundamental pathogenic mechanism in neurodegeneration, especially in the context of Parkinson's disease (PD), this represents a promising target for therapeutic intervention. Ursodeoxycholic acid (UDCA), a clinical drug used for liver disease, possesses antioxidant and mitochondrial repair properties. Recently, it has gained attention as a potential therapeutic option for treating various neurodegenerative diseases. However, multiple barriers, including the blood-brain barrier (BBB) and cellular/mitochondrial membranes, significantly hinder the efficient delivery of therapeutic agents to the damaged neuronal mitochondria. Macrophage-derived nanovesicles (NVs), which can traverse the BBB in response to brain inflammation signals, have demonstrated promising tools for brain drug delivery. Nevertheless, natural nanovesicles inherently lack the ability to specifically target mitochondria. Herein, artificial NVs are loaded with UDCA and then functionalized with triphenylphosphonium (TPP) molecules, denoted as UDCA-NVs-TPP. These nanovesicles specifically accumulate in damaged neuronal mitochondria, reduce oxidative stress, and enhance ATP production by 42.62%, thereby alleviating neurotoxicity induced by 1-methyl-4-phenylpyridinium (MPP+). Furthermore, UDCA-loaded NVs modified with TPP successfully cross the BBB and accumulate in the striatum of PD mice. These nanoparticles significantly improve PD symptoms, as demonstrated by a 48.56% reduction in pole climb time, a 59.09% increase in hanging ability, and the restoration of tyrosine hydroxylase levels to normal, achieving remarkable therapeutic efficacy. Our work highlights the immense potential of these potent UDCA-loaded, mitochondria-targeting nanovesicles for efficient treatment of PD and other central neurodegenerative diseases.

Shikonin Ameliorates Rotenone-Induced Neurotoxicity Through Inhibition of Apoptosis via IGF-1R/PI3K/AKT Pathway in a Parkinson's Disease-Associated SH-SY5Y Cell Model

Parkinson's disease (PD) is the second most common multifactorial neurodegenerative disorder caused by several genetics and environmental factors. Rotenone a pesticide with mitotoxicity causes cytosolic proteopathy resulting in PD-associated apoptosis and modulations in cell survival pathways. Shikonin, a naphthoquinone compound extracted from the Lithospermum erythrorhizon herb, was investigated in this study for its neuroprotective properties and underlying molecular mechanisms against rotenone-induced cellular apoptosis and survival in SH-SY5Y cells. The molecular docking analysis of apoptotic proteins against Shikonin revealed that they showed a binding affinity with BAD. Shikonin effectively countered the loss of cell viability induced by rotenone, rescued annexin-positive apoptotic cells, and dose-dependently suppressed the generation of reactive oxygen species. Pre-treatment with Shikonin prevented the morphological aberrations like shrining of neurites leading to decreased LDH leakage and NO release caused due to the rotenone treatment. The α-synucleinopathy is a prime hallmark of PD, Shikonin mitigated the rotenone-induced aggregation of α-synuclein as seen from confocal imaging. Furthermore, Shikonin treatment reversed the rotenone-induced excessive production of reactive oxygen species, activation of caspases (-8 and -3), and mitochondrial dysfunction, as evidenced by the restoration of mitochondrial membrane potential and cellular ATP levels. Western blot and qPCR analysis revealed that Shikonin heightened the IGF1R/PI3K/AKT signaling associated with cell survival while concurrently downregulating rotenone-induced intrinsic apoptotic pathways. These findings underscore Shikonin as a promising candidate to prevent the onset of pesticide-induced Parkinson's disease and potentially other oxidative stress-related neurodegenerative disorders.

Dopamine Toxicity Induces ROS-Dependent Death of Murine Neuroblastoma Cells: Impact on the Interactions of Cofilin With UCHL1 and MMP9

The death of dopaminergic neurons, a hallmark event during Parkinson's disease (PD), leads to increased dopamine concentration in the neuronal micro-environment. Keeping this in mind, we intend to understand the impact of elevated dopamine concentration on molecular interactions among proteins and the stability of the neuronal cytoskeleton. We used differentiated N2A cells and exposed them to 100 µM DA for 24 h. Evaluations of cell death, measurement of the concentration of DA oxidation products and reactive oxygen species (ROS), conventional RT-PCR, western blotting, zymography, reverse zymography, co-immunoprecipitation, mitochondrial transmembrane potential, confocal imaging, and in-silico studies were performed thereon. We observed that a significant number of viable N2A cells underwent ROS-dependent apoptotic cell death under elevated media DA concentrations. An altered transcriptional pattern of alpha-synuclein, UCHL1, and cofilin genes and their respective gene products were also observed. The activity and expression of matrix metalloproteinases9 (MMP9), involved in neuro-inflammation, was enhanced upon DA-exposure. Further, DA exposure also led to degradation of actin cytoskeleton. In silico studies revealed that interactions of Cofilin with UCHL1 and MMP9 were altered in dopamine-rich microenvironment. This result was further validated by co-immunoprecipitation experiments. Collectively our observations with murine neuroblastoma cells suggest that DA toxicity alters interaction patterns among intracellular proteins and degrades neuronal cytoskeleton that finally leads to cell death. Our study unveils a new frontier in PD treatment by paving the way for the development of specific drugs targeting the DA altered protein interactions.

Association between oxidative balance score and all-cause mortality in stroke survivors

Stroke is the second leading cause of death globally. Oxidative stress plays a critical role in the development of stroke. The Oxidative Balance Score (OBS) is a tool used to assess the combined impact of diet and lifestyle on the body's antioxidant capacity. The study included stroke survivors from the National Health and Nutrition Examination Survey (1999-2018), with a total of 1,781 participants and a median follow-up duration of 6.5 years, during which 786 participants (39.59%) died. The relationship between OBS and all-cause mortality was assessed using the Cox proportional hazards model. The results indicated that individuals in higher OBS quartiles had lower mortality rates. Specifically, patients in the fourth quartile had a 41% reduced risk of all-cause mortality compared to those in the first quartile (HR = 0.59, 95% CI = 0.42-0.84, p = 0.003). Restricted cubic spline analysis revealed a linear inverse relationship between OBS and all-cause mortality. Subgroup analysis further demonstrated that the inverse association persisted across various population subgroups. Overall, our study suggests that higher levels of OBS can reduce the risk of all-cause mortality in stroke survivors and provides new evidence for their diet and lifestyle.

Intestine-Decipher Engineered Capsules Protect Against Sepsis-induced Intestinal Injury via Broad-spectrum Anti-inflammation and Parthanatos Inhibition

Sepsis is a severe systemic inflammatory syndrome characterized by a dysregulated immune response to infection, often leading to high mortality rates. The intestine, owing to its distinct structure and physiological environment, plays a pivotal role in the pathophysiology of sepsis. It functions as the "central organ" or "engine" in the progression of sepsis, with intestinal injury exacerbating the condition. Despite the availability of current therapies that offer partial symptom relief, they fall short of adequately protecting the intestinal barrier. In this study, an advanced nanodrug formulation (OLA@MΦ NPs) is developed by coating macrophage membranes onto polymeric organic nanoparticles encapsulating olaparib. When loaded into pH-responsive capsules, an intestine-decipher engineered capsule (cp-OLA@MΦ NPs) is successfully formulated. Upon oral administration in septic mice, these capsules withstand gastric acid and release their contents in the intestine, specifically targeting injured tissues. The released OLA@MΦ NPs effectively neutralize pro-inflammatory cytokines via macrophage membrane receptors, while olaparib inhibits intestinal epithelial parthanatos (a form of programmed cell death) by suppressing poly(ADP-ribose) polymerase 1 (PARP1) activation. This strategy significantly reduces bacterial translocation, slows the progression of sepsis, and enhances survival in septic mice, thus presenting a promising therapeutic approach for sepsis in clinical applications.

The mechanism of SiJunZi decoction in the treatment of Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disease, but treatment options for PD are limited, and drug development has reached a bottleneck. With the progress of the aging population, the number of PD patients in China is increasing day by day, imposing a heavy burden on patients and society. Therefore, it is urgent to explore targeted medicine based on the pathogenesis of PD and disease targets. Ancient physicians have used the traditional Chinese medicine formula SiJunZi decoction (SJZD) to treat PD. However, it is less commonly used clinically now, and its pharmacological mechanism still needs to be further elucidated. In this study, based on network pharmacology research and molecular docking technology, the mechanism of SJZD in treating PD was revealed, showing that the extract of SJZD acts on cell microdomain membranes and lipid rafts, affecting ubiquitin-protein ligase binding and ubiquitin-like protein ligase binding processes, and plays a role in neurogenesis. Molecular docking results showed that Ellipticine and Hederagenin in SJZD exhibited significant effects on targets: CASP3, BCL2, and PTGS2. The effect of SJZD reversing MPP+-induced SH-SY5Y cells injury was verified by experiments, concentrations ranging from 5ug/mL to 0.1ug/mL showed significant cell protection at 24 h.

Acteoside alleviates salsolinol-induced Parkinson's disease by inhibiting ferroptosis via activating Nrf2/SLC7A11/GPX4 pathway

Salsolinol (SAL), i.e.1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroiso-quinoline, is a dopamine metabolite and endogenous neurotoxin that is toxic to dopaminergic neurons, and is involved in the genesis of Parkinson's disease (PD). However, the machinery underlying SAL induces neurotoxicity in PD are still being elucidated. In the present study, we first used RNA sequencing (RNAseq) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis to detect differentially expressed genes in SAL-treated SH-SY5Y cells. We found that ferroptosis-related pathway was enriched by SAL, which was validated by in vitro and in vivo SAL models. SAL inducing ferroptosis through downregulating SLC7A11/GPX4 in SH-SY5Y cells, which neurotoxic effect was reversed by ferroptosis inhibitors deferoxamine (DFO) and ferrostatin-1 (Fer-1). Acteoside, a phenylethanoid glycoside of plant origin with neuroprotective effect, attenuates SAL-induced neurotoxicity by inhibiting ferroptosis in in vitro and in vivo PD models through upregulating SLC7A11/GPX4. Mechanistically, acteoside activates Nrf2. Nrf2 inhibitor ML385 abolished acteoside-mediated increased SLC7A11/GPX4 and neuroprotection against SAL in SH-SY5Y cells. Meanwhile, the PI3K inhibitor LY294002 suppressed the acteoside-induced Nrf2 expression and ensued decreased expression of SLC7A11/GPX4 in SAL-treated SH-SY5Y cells. Taken together, these results demonstrate that salsolinol-induced PD through inducing ferroptosis via downregulating SLC7A11/GPX4. Acteoside attenuates SAL-induced PD through inhibiting ferroptosis via activating PI3K/Akt-dependant Nrf2. The present study revealed a novel molecular mechanisms underlining SAL-induced neurotoxicity via induction of ferroptosis in PD, and uncovered a new pharmacological effect against PD through inhibiting ferroptosis. This study highlights SAL-induced ferroptosis -dependent neurotoxicity as a potential therapeutic target in PD.

Z/Ce@hemin enzymes with enhanced peroxidase activity for monitoring and screening the oxidative stress models of Parkinson's disease

Inspired by natural enzymes, artificial enzymes have garnered significant interest due to their simplicity of production, robustness under harsh conditions, and enhanced stability. This study introduces, for the first time, a novel Z/Ce@hemin composite enzyme, constructed by anchoring hemin onto zeolitic imidazolate framework-8 (ZIF-8)-encapsulated ceria (CeO2) nanoparticles. This innovative design overcomes the challenges of hemin dimerization, enhances substrate affinity, and accelerates mass transport, leading to significantly improved peroxidase-like activity. The enzyme also demonstrates remarkable stability and resistance to environmental interference. Utilizing this Z/Ce@hemin composite, a sensitive and selective colorimetric detection system was developed for rapid and accurate quantification of hydrogen peroxide (H2O2), a key oxidative stress marker. This approach was successfully applied in cellular models and Caenorhabditis elegans models of Parkinson's disease, enabling precise monitoring of H2O2. The study provides a groundbreaking platform for oxidative stress modeling and expands possibilities in neurodegenerative disease research and therapeutic screening.

Early detection of Parkinson's disease through multiplex blood and urine biomarkers prior to clinical diagnosis

Blood and urine biomarkers are commonly used to diagnose and monitor chronic diseases. We initially screened 67 biomarkers, including 4 urine biomarkers and 63 blood biomarkers, and identified 13 blood biomarkers significantly associated with Parkinson's disease (PD). Among these, we discovered three novel markers demonstrating strong associations: phosphate (P = 1.81 × 10-3), AST/ALT ratio (P = 8.53 × 10-6), and immature reticulocyte fraction (IRF) (P = 3.49 × 10-20). We also substantiated eight well-studied biomarkers and elucidated the roles of two previously ambiguous biomarkers. Our analyses confirmed IGF-1 (P = 7.46 × 10-29) as a risk factor, and C-reactive protein (CRP) (P = 1.43 × 10-3) as protective against PD. Genetic analysis highlighted that IRF, CRP, and IGF-1 share significant genetic loci with PD, notably at MAPT, SETD1A, HLA-DRB1, and HLA-DQA1. Furthermore, Mendelian randomization (MR) analysis suggested potential causal associations between IGF-1, CRP, and PD. We identified several blood biomarkers that may be associated with the risk of developing PD, providing valuable insights for further exploration of PD-related biomarkers.

Glycolytic pathways: The hidden regulators in Parkinson's disease

Parkinson's disease (PD) is a widespread neurodegenerative condition [1]; however, its association with glycolysis, specifically the activity of genes related to glycolysis, has not yet been explored. We downloaded 3 datasets related to PD from the GEO database and identified the glycolytic genes related to PD. Subsequently, GO and KEGG enrichment analyses were conducted. We constructed a PD diagnosis model using the SVM algorithm for differentially expressed glycolysis-related genes and verified the model with LASSO regression analysis. Next, we constructed a regulatory network of genes that were differentially expressed with respect to glycolysis. Finally, the amount of immune cell infiltration was analyzed in PD samples, and the correlation between differential genes and immune cells was calculated. A total of 64 differentially expressed glycolytic genes associated with PD were screened. Then, a GO analysis was conducted, followed by KEGG and GASE enrichment analyses. Within the established PD diagnostic model, 26 genes that were differentially expressed and linked to glycolysis showed strong statistical significance. After further screening, a diagnostic model for PD including seven key genes was established. Further analysis showed that ABHD5 most strongly correlated with neutrophils (r = 0.507). The key gene SMAD3 was strongly negatively associated with gamma delta T cells (r = -0.488). This research offered a theoretical foundation for the association between glycolysis and PD. Seven glycolytic genes were identified as significantly linked to PD and warrant additional research.

The Neuroprotective Effects of Primary Functional Components Mulberry Leaf Extract in Diabetes-Induced Oxidative Stress and Inflammation

Diabetes-associated neurodegeneration may result from increased oxidative stress in the brain under hyperglycemic conditions, which leads to neuronal cell death. The current study employs the neuroblastoma cell line SH-SY5Y and db/db mouse model of diabetes maintained on a high-fat diet to investigate the neuroprotective effects of the primary functional components of mulberry (Morus alba Linn) leaf extract (MLE), chlorogenic acid (CGA), and neochlorogenic acid (NCGA). CGA and NCGA demonstrated the ability to enhance the activities of the antioxidant enzymes superoxide dismutase and glutathione peroxidase, and attenuate inflammation via regulating nuclear factor erythroid 2-related factor 2 (Nrf2), nuclear factor-κB (NFκB), and inflammatory cytokines, thereby protecting SH-SY5Y cells from oxidative damage induced by palmitic acid and high glucose. CGA and NCGA were found to decrease the expression of proinflammatory proteins α-synuclein and amyloid-β (Aβ). In addition, CGA and NCGA treatments increased the expression of tyrosine hydroxylase (TH) and brain-derived neurotrophic factor (BDNF). Furthermore, MLE supplementation in the animal model resulted in decreased levels of α-synuclein and Aβ concomitant with an elevated expression of TH. These experimental findings suggest that the neuroprotective effects of CGA and NCGA may be mediated via three pathways: reducing oxidative stress, decreasing neuronal inflammation, and enhancing BDNF expression.

Palmatine Ameliorates Motor Deficits and Dopaminergic Neuron Loss by Regulating NLRP3 Inflammasome through Mitophagy in Parkinson's Disease Model Mice

NLRP3 inflammasomes-mediated proinflammatory response and mitochondrial dysfunction play a critical role in the etiology and pathogenesis of Parkinson's disease. Negative regulation of NLRP3 inflammasome activation through mitophagy may be an important strategy to control NLRP3 inflammasome-mediated proinflammatory responses. Palmatine (PAL), an isoquinoline alkaloid found in various of plants, has potent pharmacological effects such as anti-inflammatory and anti-oxidation. However, the specific role of PAL in the pathology of Parkinson's disease remains unclear. In this study, we found that treatment with PAL improved motor deficits and reduced the loss of dopaminergic neurons in MPTP mice. Further results showed that PAL promoted mitophagy and inhibited the proinflammatory response mediated by NLRP3 inflammasomes. In addition, chloroquine (CQ, mitophagy inhibitor) attenuated the ameliorative effects of PAL on the motor deficits and dopaminergic neuron damage, as well as the inhibitory effect of PAL on NLRP3 inflammasome. Collectively, these results provide strong evidence that PAL ameliorates motor deficits and dopaminergic neuron death in Parkinson's disease, and the mechanism may be related to its inhibition of NLRP3 inflammasome activation via promoting mitophagy.

Ferroptosis and cognitive impairment: Unraveling the link and potential therapeutic targets

Neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases, share key characteristics, notably cognitive impairment and significant cell death in specific brain regions. Cognition, a complex mental process allowing individuals to perceive time and place, is disrupted in these conditions. This consistent disruption suggests the possibility of a shared underlying mechanism across all neurodegenerative diseases. One potential common factor is the activation of pathways leading to cell death. Despite significant progress in understanding cell death pathways, no definitive treatments have emerged. This has shifted focus towards less-explored mechanisms like ferroptosis, which holds potential due to its involvement in oxidative stress and iron metabolism. Unlike apoptosis or necrosis, ferroptosis offers a novel therapeutic avenue due to its distinct biochemical and genetic underpinnings, making it a promising target in neurodegenerative disease treatment. Ferroptosis is distinguished from other cellular death mechanisms, by distinctive characteristics such as an imbalance of iron hemostasis, peroxidation of lipids in the plasma membrane, and dysregulated glutathione metabolism. In this review, we discuss the potential role of ferroptosis in cognitive impairment. We then summarize the evidence linking ferroptosis biomarkers to cognitive impairment brought on by neurodegeneration while highlighting recent advancements in our understanding of the molecular and genetic mechanisms behind the condition. Finally, we discuss the prospective therapeutic implications of targeting ferroptosis for the treatment of cognitive abnormalities associated with neurodegeneration, including natural and synthetic substances that suppress ferroptosis via a variety of mechanisms. Promising therapeutic candidates, including antioxidants and iron chelators, are being explored to inhibit ferroptosis and mitigate cognitive decline.

Computational analysis of Urolithin A as a potential compound for anti-inflammatory, antioxidant, and neurodegenerative pathways

Urolithin A, an active precursor derived from the metabolism of ellagitanins in rats and humans, is known for its potential health benefits, including stimulating mitophagy and promoting muscular skeletal function. While experimental studies have demonstrated Urolithin A's potential to enhance cellular health, the detailed molecular interactions through which Urolithin A exerts its effects are not fully elucidated. In this study, we investigated the anti-inflammatory, antioxidation and neuroprotective abilities of Urolithin A in selected targets using molecular docking and molecular dynamics simulation methods. Molecular docking studies revealed the strong affinity for receptors involved in inflammation activities, including human p38 MAP kinase (4DLI) with -10.1 kcal/mol interacting with SER252, LYS249, and ASP294 residues. The binding energy in the 5KIR target was -8.6 kcal/mol, interacting with GLN203 through hydrogen bond, and lastly, 1A9U with an affinity of -6.8 with no hydrogen bond formed with Urolithin A and interacts with van der Waals interactions. In oxidant targets, the influence of Urolithin was observed in 1OG5 with -7.9 kcal/mol interacting with GLN185, PHE447. For the 1M17 target, the binding affinity was -7.7 kcal/mol interacting with THR95 residue and 1ZXM target at -7.4 kcal/mol interacting with TYR36, TYR216, and LEU234 residues. The neuroprotective ability of urolithin A was observed in selected targets for acetylcholinesterase; the binding energy was -9.7 kcal/mol interacting with van der Waals and π interactions; for the 1GQR target, the binding energy was -9.9 kcal/mol interacting with van der Waals and π interactions and for β-amylase (1iyt) the binding energy was -5.5 forming hydrogen bond with SER8, GLN15 residues. Molecular Dynamics simulations at 100 ns of Urolithin A compared with reference 4DLI. The Urolithin A-4DLI complex exhibited greater stability than the reference receptor, as confirmed by RMSD, RMSF, Radius of Gyration, Hydrogen bond, and SASA analyses.

Oxidative stress and mitochondrial impairment: Key drivers in neurodegenerative disorders

Mitochondrial dysfunction and oxidative stress are critical factors in the pathogenesis of neurodegenerative diseases. The complex interplay between these factors exacerbates neuronal damage and accelerates disease progression. In neurodegenerative diseases, mitochondrial dysfunction impairs ATP production and promotes the generation of reactive oxygen species (ROS). The accumulation of ROS further damages mitochondrial DNA, proteins, and lipids, creating a vicious cycle of oxidative stress and mitochondrial impairment. This review aims to elucidate the mechanisms by which mitochondrial dysfunction and oxidative stress lead to neurodegeneration, and to highlight potential therapeutic targets to mitigate their harmful effects.

Targeting ferroptosis in gastrointestinal tumors: Interplay of iron-dependent cell death and autophagy

Ferroptosis is a regulated cell death mechanism distinct from apoptosis, autophagy, and necroptosis, marked by iron accumulation and lipid peroxidation. Since its identification in 2012, it has developed into a potential therapeutic target, especially concerning GI disorders like PC, HCC, GC, and CRC. This interest arises from the distinctive role of ferroptosis in the progression of diseases, presenting a new avenue for treatment where existing therapies fall short. Recent studies emphasize the promise of focusing on ferroptosis to fight GI cancers, showcasing its unique pathophysiological mechanisms compared to other types of cell death. By comprehending how ferroptosis aids in the onset and advancement of GI diseases, scientists aim to discover novel drug targets and treatment approaches. Investigating ferroptosis in gastrointestinal disorders reveals exciting possibilities for novel therapies, potentially revolutionizing cancer treatment and providing renewed hope for individuals affected by these tumors.

Adolescent mice exposed to TBI developed PD-like pathology in middle age

Traumatic brain injury (TBI) is identified as a risk factor for Parkinson's disease (PD), which is a neurodegenerative disease characterized by the loss of dopaminergic neurons in the substantia nigra (SN). However, the precise mechanism by which chronic TBI initiates PD pathogenesis is not yet fully understood. In our present study, we assessed the chronic progression and pathogenesis of PD-like behavior at different intervals in TBI mice. More than half of the mice exhibited PD-like behavior at 6 months post injury. PD-like behavioral dysfunction and pathological changes were aggravated with the injured time extension in chronic phase of TBI. The loss of tyrosine hydroxylase positive (TH+) neurons in the SN were partly associated with the accumulation of misfolded a-Synuclein and the cytoplasmic translocation of TDP-43 from nuclear. Moreover, the present of chronic inflammation was observed in SN of TBI mice, as evidenced by the enhancement of proinflammatory cytokines and reactive astrocytes and microgliosis post lesion. The enhanced phagocytosis of reactive microglia accounted for the reduction of dendrite spines. Our results revealed that chronic inflammation associated with the damage of TH+ neurons and the development of progressive PD-like pathology after chronic TBI in mice. Our study shed new light on the TBI-triggered molecular events on PD-like pathology. Additional research is required to have a deeper understanding of the molecular factors underlying the impairment of dopaminergic neurons following TBI.

Targeting the Interplay Between Autophagy and the Nrf2 Pathway in Parkinson's Disease with Potential Therapeutic Implications

Parkinson's disease (PD) is a prevalent neurodegenerative disorder marked by the progressive degeneration of midbrain dopaminergic neurons and resultant locomotor dysfunction. Despite over two centuries of recognition as a chronic disease, the exact pathogenesis of PD remains elusive. The onset and progression of PD involve multiple complex pathological processes, with dysfunctional autophagy and elevated oxidative stress serving as critical contributors. Notably, emerging research has underscored the interplay between autophagy and oxidative stress in PD pathogenesis. Given the limited efficacy of therapies targeting either autophagy dysfunction or oxidative stress, it is crucial to elucidate the intricate mechanisms governing their interplay in PD to develop more effective therapeutics. This review overviews the role of autophagy and nuclear factor erythroid 2-related factor 2 (Nrf2), a pivotal transcriptional regulator orchestrating cellular defense mechanisms against oxidative stress, and the complex interplay between these processes. By elucidating the intricate interplay between these key pathological processes in PD, this review will deepen our comprehensive understanding of the multifaceted pathological processes underlying PD and may uncover potential strategies for its prevention and treatment.

Integrating network pharmacology with molecular docking and dynamics to uncover therapeutic targets and signaling mechanisms of vitamin D3 in Parkinson's disease

Parkinson's disease (PD) is a chronic neurodegenerative disorder marked by dopaminergic neuron degeneration in the substantia nigra. Emerging evidence suggests vitamin D3 (VD) plays a therapeutic role in PD, but its precise molecular mechanisms remain unclear. This study employed network pharmacology and bioinformatics to identify VD's hub targets and related pathways. We identified 24 VD's anti-PD targets, with estrogen receptor 1, estrogen receptor 2 (ESR2), sodium-dependent norepinephrine transporter, and insulin-like growth factor 1 receptor emerging as hub targets. Gene enrichment analysis elucidated that VD's anti-PD mechanism is closely related to the estrogen signaling pathway. Additionally, two-sample Mendelian randomization suggested a positive causal relationship between 25-hydroxyvitamin D and estrogen levels in vivo. To verify the interaction between VD and the hub drug targets, we performed molecular docking and kinetic simulations, finding the strongest interaction between VD and ESR2. Further Mendelian randomization analysis of drug targets confirmed the significant effect of the ESR2 drug target on PD risk. Single-cell nuclear sequencing of dopaminergic neurons, coupled with GSEA analysis, indicated that ESR2 activation upregulates the neuroactive ligand-receptor interaction signaling pathway and downregulates the Parkinson's disease pathway, thereby exerting a neuroprotective effect. In summary, our findings suggest that VD supplementation can not only elevate estradiol levels in humans but also directly activate ESR2, thereby modulating the estrogen signaling pathway in PD patients and providing neuroprotection. These predictive biological targets offer promising avenues for future clinical applications in Parkinson's disease treatment.

Associations Between Diabetes Mellitus and Neurodegenerative Diseases

Diabetes mellitus (DM) and neurodegenerative diseases/disturbances are worldwide health problems. The most common chronic conditions diagnosed in persons 60 years and older are type 2 diabetes mellitus (T2DM) and cognitive impairment. It was found that diabetes mellitus is a major risk for cognitive decline, dementia, Parkinson's disease (PD), Alzheimer's disease (AD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS) and other neurodegenerative disorders. Different mechanisms of associations between these diseases and diabetes mellitus have been suggested. For example, it is postulated that an impaired intracellular insulin signaling pathway, together with hyperglycemia and hyperinsulinemia, may cause pathological changes, such as dysfunction of the mitochondria, oxidative stress inflammatory responses, etc. The association between diabetes mellitus and neurodegenerative diseases, as well as the mechanisms of these associations, needs further investigation. The aim of this review is to describe the associations between diabetes mellitus, especially type 1 (T1DM) and type 2 diabetes mellitus, and selected neurodegenerative diseases, i.e., Alzheimer's disease, Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis. Suggested mechanisms of these associations are also described.

Noncoding RNA Terc-53 and hyaluronan receptor Hmmr regulate aging in mice

One of the basic questions in the aging field is whether there is a fundamental difference between the aging of lower invertebrates and mammals. A major difference between the lower invertebrates and mammals is the abundancy of noncoding RNAs, most of which are not conserved. We have previously identified a noncoding RNA Terc-53 that is derived from the RNA component of telomerase Terc. To study its physiological functions, we generated two transgenic mouse models overexpressing the RNA in wild-type and early-aging Terc-/- backgrounds. Terc-53 mice showed age-related cognition decline and shortened life span, even though no developmental defects or physiological abnormality at an early age was observed, indicating its involvement in normal aging of mammals. Subsequent mechanistic study identified hyaluronan-mediated motility receptor (Hmmr) as the main effector of Terc-53. Terc-53 mediates the degradation of Hmmr, leading to an increase of inflammation in the affected tissues, accelerating organismal aging. adeno-associated virus delivered supplementation of Hmmr in the hippocampus reversed the cognition decline in Terc-53 transgenic mice. Neither Terc-53 nor Hmmr has homologs in C. elegans. Neither do arthropods express hyaluronan. These findings demonstrate the complexity of aging in mammals and open new paths for exploring noncoding RNA and Hmmr as means of treating age-related physical debilities and improving healthspan.

N6-methyladenosine mediated-NRF2 signaling pathway attenuates cadmium cytotoxicity by inhibiting oxidative damage in bronchial epithelial cells

Although N6-methyladenosine (m6A) and its regulatory proteins were involved in multiple cellular damage processes, the roles of m6A and its regulatory proteins in cadmium-induced pulmonary cell damage remain largely unknown. Our present data indicated that cadmium exposure caused serious damage in bronchial epithelial cells, as evidenced by reduction of cell viability and elevation of oxidative damage and apoptosis. These processes were accompanied by alterations of m6A modification and its regulatory proteins (FTO, ALKBH5, YTHDC2). It is noteworthy that pretreatment with the m6A agonist entacapone (ENT) markedly attenuated the detrimental effects of cadmium, including cell death, oxidative damage, and the activation of the nuclear factor erythroid 2-related factor 2 (NRF2）signalling pathway. Conversely, the detrimental effects of CdSO4 were significantly exacerbated when m6A levels were inhibited by 3-deazidyladenosine (DAA). Further prediction result revealed that multiple m6A-modified sites occur on NRF2 mRNA with high confidence level, implicating that m6A modification on NRF2 mRNA may affect the protein expression of NRF2. In conclusion, our data together suggest that m6A modification play critical roles in cadmium-induced bronchial epithelial cell damage, during which NRF2 signaling pathway may act as an important bridge for m6A modification to regulate cellular damage. This study offer a promising avenue for further investigation into the mechanisms underlying cadmium-induced bronchial epithelial cell damage from the perspective of RNA epigenetics.

Stearic acid metabolism in human health and disease

Named after the Greek term for "hard fat", stearic acid has gradually entered people's field of vision. As an important component of various physiological cellular functions, stearic acid plays a regulatory role in diverse aspects of energy metabolism and signal transduction. Its applications range from serving as a bodily energy source to participating in endogenous biosynthesis. Similar to palmitate, stearic acid serves as a primary substrate for the stearoyl coenzyme A desaturase, which catalyzes the conversion of stearate to oleate and is involved in the synthesis of triglyceride and other complex lipids. Additionally, stearic acid functions as a vital signaling molecule in pathological processes such as cardiovascular diseases, diabetes development, liver injury and even nervous system disorders. Therefore, we conduct a comprehensive review of stearic acid, summarizing its role in various diseases and attempting to provide a systematic overview of its homeostasis, physiological functions, and pathological process. From a medical standpoint, we also explore potential applications and discuss stearic acid as a potential therapeutic target for the treatment of human diseases.

Intranasal AdipoRon mitigates motor and cognitive deficits in hemiparkinsonian rats through neuroprotective mechanisms against oxidative stress and synaptic dysfunction

While motor symptoms are the most well-known manifestation of Parkinson's disease (PD), patients may also suffer from non-motor signs like cognitive impairments. The adiponectin receptor agonist AdipoRon (Adipo) has shown neuroprotective effects in preclinical studies. The objective of this study was to determine the potential benefits of chronic intranasal treatment of Adipo on motor function and cognitive performance in a hemiparkinsonian rat model caused by injecting 6-hydroxydopamine (6-OHDA) into the left forebrain bundle. After one week, PD rats were given either a vehicle or one of three dosages of Adipo (0.1, 1, and 10 μg) or levodopa (10 mg/kg orally) daily for 21 days. Recognition and spatial memory were determined using the novel object recognition test (NORT) and the Barnes maze test, respectively. The hippocampal tissues of the animals were harvested to examine oxidative stress status as well as the protein expressions of brain-derived neurotrophic factor (BDNF) and postsynaptic density protein 95 (PSD-95). In hemiparkinsonian rats, motor impairments, recognition memory, and spatial memory were all improved by chronic intranasal Adipo at 1 and 10 μg. Furthermore, we found that unilateral 6-OHDA injection elevated hippocampal oxidative stress (ROS) while concurrently reducing total antioxidant capacity (TAC), BDNF, PSD-95, and antioxidant enzymes (SOD, GPx). However, Adipo 10 μg significantly reduced these biochemical alterations in the hippocampus of 6-OHDA-lesioned rats. Chronic intranasal Adipo ameliorated spatial and recognition memory deterioration in hemiparkinsonian rats, presumably by increasing hippocampal synaptic protein levels, reducing oxidative stress, and increasing BDNF.

The Interplay Between Accumulation of Amyloid-Beta and Tau Proteins, PANoptosis, and Inflammation in Alzheimer's Disease

Alzheimer's disease (AD) is a common progressive neurodegenerative disorder, and the vast majority of cases occur in elderly patients. Recently, the accumulation of Aβ and tau proteins has drawn considerable attention in AD research. This review explores the multifaceted interactions between these proteins and their contribution to the pathological landscape of AD, encompassing synaptic dysfunction, neuroinflammation, and PANoptosis. PANoptosis is a collective term for programmed cell death (PCD) modalities that encompass elements of apoptosis, pyroptosis, and necroptosis. The accumulation of Aβ peptides and tau proteins, along with the immune response in brain cells, may trigger PANoptosis, thus advancing the progression of the disease. Recent advancements in molecular imaging and genetics have provided deeper insights into the interactions between Aβ peptides, tau proteins, and the immune response. The review also discusses the role of mitochondrial dysregulation in AD. The exploration of the interplay between neurodegeneration, immune responses, and cell death offers promising avenues for the development of innovative treatments.

Pyroptosis mediated by Parkin-NLRP3 negative feedback loop contributed to Parkinson's disease induced by rotenone

Rotenone remains an efficient pesticide used extensively in agriculture, leading to neurotoxicity and the increase of the prevalence of Parkinson's disease (PD). Previous studies indicated that Parkin, a neurohomeostasis regulatory factor, and NOD-like receptor protein 3 (NLRP3), a core factor driving the inflammatory response, interacted with each other, which affected neuroinflammation occurrence. However, whether rotenone accelerated PD progression via Parkin-NLRP3 loop and the specific mechanisms were still unclear. Here, a novel negative feedback mechanism of Parkin-NLRP3 that regulated PD caused by rotenone was certified. Rotenone treatment induced neurodegeneration in vitro- and vivo-models. The activation of NLRP3 inflammasome and Parkin was increased and decreased, respectively, and the expression of pyroptosis related proteins was up-regulated, because of the addition of rotenone. Notably, the overexpression of Parkin promoted NLRP3 ubiquitination, which down regulated pyroptosis mediated by NLRP3, protected mitochondrial function as well as preventing neurodegeneration. Additionally, the NLRP3 inhibitor MCC950 restored the activation of Parkin and down regulated pyroptosis mediated by NLRP3 in rotenone-induced PD. It was revealed that the Parkin-NLRP3 negative feedback loop participated in rotenone-induced PD by regulating pyroptosis, representing a new idea for the prevention and treatment of neurodegenerative diseases.

Progressive iron overload in middle-aged mice impairs olfactory function, triggers lipid oxidation and induces apoptosis

Introduction

This study aims to investigate the progressive impact of chronic iron overload on the olfactory bulb, a region significantly affected in early neurodegenerative diseases like Parkinson's and Alzheimer's. The focus is on understanding how iron accumulation leads to oxidative stress, mitochondrial dysfunction, and neuronal damage over time in middle-aged mice.

Method

The mice were continuously administered FC for a duration of 16 weeks, and the olfactory behavior of the mice was observed at intervals of 4 weeks. Inductively coupled plasma mass spectrometry (ICP-MS) was employed to detect alterations in iron content within the olfactory bulb of the mice, while levels of lipid peroxidation and antioxidant indexes were assessed using biochemical kits. Additionally, western blotting and qPCR techniques were utilized to analyze transcriptional and expression changes in proteins and genes related to iron metabolism. Furthermore, microstructural modifications as well as mitochondrial observations were conducted through paraffin sectioning and transmission electron microscopy (TEM).

Result

A significant and progressive increase in iron accumulation in the olfactory bulb, starting from week 8 and peaking at week 16. This accumulation coincided with a decline in olfactory function observed at week 12. Key markers of oxidative stress, such as 4-HNE and MDA, were elevated in specific layers, and antioxidant defenses were reduced. Mitochondrial damage became evident from week 8, with caspase-3 activation indicating increased apoptosis, particularly in the granular layer. This study is to demonstrate the link between chronic iron overload and progressive olfactory dysfunction in the context of neurodegenerative diseases. It provides evidence that iron-induced oxidative stress and mitochondrial damage in the olfactory bulb contribute to early sensory deficits, suggesting that the olfactory bulb's selective vulnerability can serve as an early biomarker for neurodegenerative conditions.

Conclusion

Chronic iron overload leads to progressive oxidative damage, mitochondrial dysfunction, and apoptosis in the olfactory bulb, causing sensory deficits. Targeting iron accumulation and oxidative damage may offer new strategies for early intervention in neurodegenerative diseases, highlighting the importance of addressing iron dysregulation.

Exploring the causal link between serum amino acids and Parkinson's disease: a Mendelian randomization approach

This study aimed to explore the causal relationships between multiple blood amino acids (BAAs) and the Parkinson's disease (PD). We downloaded genome-wide association study (GWAS) data for BAAs and PD from the OpenGWAS database, screened single nucleotide polymorphisms (SNPs) from the data, and evaluated the causal relationship between BAA levels and PD using the inverse variance weighted (IVW) method. The sensitivity analysis was also conducted. After SNP screening, three amino acid indicators were identified: met-a-308 (phenylalanine), met-a-584 (X-12100 hydroxytryptophan), and met-a-337 (5-hydroxyproline), which showed significant causal relationship with the occurrence of PD. There was no significant heterogeneity or horizontal pleiotropy, and the results were stable. The multivariate MR analysis showed that the mediating effects generated by the introduction of multiple variables were not significant. In conclusion, phenylalanine, X-12,100 hydroxytryptophan, and 5-hydroxyproline have a causal relationship with the occurrence of PD and may be potential early screening biomarkers and blocking targets.

Pharmacodynamic insights into maresin 1: Enhancing flap viability via the keap1/Nrf2 axis to control ROS-driven apoptosis and ferroptosis

Random flaps are widely used in tissue reconstruction, but the high incidence of flap necrosis after operation remains a significant challenge. Maresin 1 (MaR1), a mediator derived from docosahexaenoic acid, has been shown to have significant effects in resolving inflammation and promoting tissue regeneration. This study investigated the role of MaR1 in the survival of random flaps. Histological analysis, laser Doppler blood flow imaging, Masson trichrome staining, and survival area analysis were used to assess the viability of the flaps. Apoptosis, ferroptosis, oxidative stress, angiogenesis, and the underlying mechanisms were explored by examining the expression of specific molecules using immunofluorescence, western blotting, and other immunological and molecular biology techniques. The findings demonstrated that MaR1 could improve flap lifespan by significantly reducing oxidative stress, apoptosis, and ferroptosis, as well as by enhancing angiogenesis. The Keap1-Nrf2 pathway was upregulated by MaR1, which inhibited ROS-mediated apoptosis and ferroptosis. The protective effect of MaR1 on flap survival was abolished by ML385. Our findings indicate that MaR1 could be a novel therapeutic agent for enhancing flap treatment outcomes.

Progress of Astrocyte-Neuron Crosstalk in Central Nervous System Diseases

Neurons are the primary cells responsible for information processing in the central nervous system (CNS). However, they are vulnerable to damage and insult in a variety of neurological disorders. As the most abundant glial cells in the brain, astrocytes provide crucial support to neurons and participate in synapse formation, synaptic transmission, neurotransmitter recycling, regulation of metabolic processes, and the maintenance of the blood-brain barrier integrity. Though astrocytes play a significant role in the manifestation of injury and disease, they do not work in isolation. Cellular interactions between astrocytes and neurons are essential for maintaining the homeostasis of the CNS under both physiological and pathological conditions. In this review, we explore the diverse interactions between astrocytes and neurons under physiological conditions, including the exchange of neurotrophic factors, gliotransmitters, and energy substrates, and different CNS diseases such as Alzheimer's disease, Parkinson's disease, stroke, traumatic brain injury, and multiple sclerosis. This review sheds light on the contribution of astrocyte-neuron crosstalk to the progression of neurological diseases to provide potential therapeutic targets for the treatment of neurological diseases.

Protective and Damaging Mechanisms of Neuromelanin-Like Nanoparticles and Iron in Parkinson's Disease

Parkinson's disease (PD) pathology speculates that neuromelanin (NM) and iron ions play a significant role in physiological and pathological conditions of PD. Because the difficult accessibility of NM has limited targeted research, synthetic melanin-like nanoparticles have been used to instead. In this report, the eumelanin and pheomelanin-like polydopamine (PDA) nanoparticles are prepared that can be used to simulate natural NM with or without chelating iron ion and studied the redox effects in vitro and in vivo on neuronal cells and PD. The synthetic pheomelanin-like PDA nanoparticles have much stronger redox activity than eumelanin-like PDA nanoparticles without or with iron ion. They can protect neurons by scavenging reactive oxygen species (ROS), while cause neuronal cell death and PD due to excessive binding of iron ions. This work provides new evidence for the relationship among two structural components of NM and iron in PD as well as displays the different effects on the roles of eumelanin and pheomelanin in redox activity under physiological or pathological conditions, which provide a new effective choice for cellular and animal models of PD and offer theoretical guidance for targeted treatment and mechanism research on PD.

Role of Glutathione in Parkinson's Disease Pathophysiology and Therapeutic Potential of Polyphenols

Oxidative stress is recognized to have a central role in the initiation and progression of Parkinson's disease (PD). Within the brain, neurons are particularly sensitive to oxidation due in part to their weak intrinsic antioxidant defense. Theoretically, neurons mostly depend on neighboring astrocytes to provide antioxidant protection by supplying cysteine-containing products for glutathione (GSH) synthesis. Astrocytes and neurons possess several amino acid transport systems for GSH and its precursors. Indeed, GSH is the most abundant intrinsic antioxidant in the central nervous system. The GSH depletion and/or alterations in its metabolism in the brain contribute to the pathogenesis of PD. Noteworthy, polyphenols possess potent antioxidant activity and can augment the GSH redox system. Numerous in vitro and in vivo studies have indicated that polyphenols exhibit potent neuroprotective effects in PD. Epidemiological studies have found an association between the consumption of dietary polyphenols and a lower PD risk. In this review, we summarize current knowledge on the biosynthesis and metabolism of GSH in the brain, with an emphasis on their contribution and therapeutic potential in PD. In particular, we focus on polyphenols that can increase brain GSH levels against PD. Furthermore, some current challenges and future perspectives for polyphenol-based therapies are also discussed.

Lutein, a versatile carotenoid: Insight on neuroprotective potential and recent advances

BACKGROUND

Neurodegenerative diseases (NDDs) are a diverse group of neurological disorders with progressive neuronal loss at specific brain regions, leading to impaired cognitive functioning, loss of neuroplasticity, severe neurological impairment, and dementia. The incidence of neurodegenerative diseases is increasing at an alarming rate with current treatments struggling to barely prolong the inevitable. The desperation to discover a therapeutic agent to treat neurodegenerative diseases and to aid in the process of healthy recovery has opened a gateway into natural pigments.

HYPOTHESIS

The xanthophyll pigment lutein may bear the potential as a therapeutic agent against NDDs.

RESULTS

Lutein plays an important role in brain development, cognitive functioning, and improving neuroplasticity. In vitro and in vivo studies revealed the neuroprotective properties of lutein against NDDs such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and cerebral ischemia. The neuroprotective effect of lutein is evidenced by the reduction of free radicals and the simultaneous strengthening of the endogenous antioxidant systems by activating the NRF-2/ERK/AKT pathway. Further, it effectively suppressed mitochondrial aberrations, excitotoxicity, overaccumulation of metals, and its resultant complications. The immunomodulatory activity of lutein prevents neuroinflammation by hindering NF-κB nuclear translocation, regulation of NIK/IKK, PI3K/AKT, MAPK/ERK, JNK pathways, and ICAM-1 downregulation. Lutein also rescued the dysregulated cholinergic system and resolved memory defects. Along with its neuroprotective properties, lutein also improved neuroplasticity by enabling neurogenesis through increased GAP-43, NCAM, and BDNF levels.

CONCLUSION

Lutein exhibits strong neuroprotective activities against various NDDs. Though the investigations are in the exploratory phase, this review presents the consolidation of scattered evidence of the neuroprotective properties of lutein and urges its further exploration in clinical studies.

mGluR7: The new player protecting the central nervous system

Metabotropic glutamate receptor 7 (mGluR7) belongs to the family of type III mGluR receptor, playing an important part in the central nervous system (CNS) through response to neurotransmitter regulation, reduction of excitatory toxicity, and early neuronal development. Drugs targeting mGluR7 (mGluR7 agonists, antagonists, and allosteric modulators) may be among the most promising agents for the treatment of CNS disorders, such as psychiatric disorders, neurodegenerative diseases, and neurodevelopmental impairments, though these potential therapies are at early stages and the data are still limited. In this review, we summarized the structure and function of mGluR7 and discussed recent progress on mGluR7 agonists and antagonists. A deeper understanding of mGluR7 will contribute to uncovering the molecular mechanisms of neuroprotection and providing a theoretical basis for the formulation of therapeutic strategies.

Exploring the Therapeutic Potential of BBB-Penetrating Phytochemicals With p38 MAPK Modulatory Activity in Addressing Oxidative Stress-Induced Neurodegenerative Disorders, With a Focus on Alzheimer's Disease

Oxidative stress plays an important role in the occurrence of neurodegenerative diseases. Previous studies indicate a strong connection between oxidative stress, inappropriate activation of the p38 MAPK signaling pathway, and the pathogenesis of neurodegenerative diseases. Although antioxidant therapy is a valid strategy to alleviate these problems, the most important limitation of this approach is the ineffectiveness of drug administration due to the limited permeability of the BBB. Therefore, BBB-penetrating p38 MAPK modulators with proper antioxidant capacity could be useful in preventing/reducing the complications of neurodegenerative disorders. The current manuscript aims to review the therapeutic capabilities of some recently reviewed naturally occurring p38 MAPK inhibitors in the management of neurodegenerative problems such as Alzheimer's disease. In data collection, we tried to use more recent studies published in high-quality journals indexed in databases Scopus, Web of Science, PubMed, and so on, but no specific time frame was considered due to the nature of the study. Our evaluations indicate that natural compounds tanshinones, protoberberines, pinocembrin, osthole, rhynchophylline, oxymatrine, schisandrin, piperine, paeonol, ferulic acid, 6-gingerol, obovatol, and trolox have significant potential for use as supplements/adjuvants in the reduction of neurodegenerative-related problems. Our findings emphasize the usefulness of BBB-penetrating phytochemicals with p38 MAPK modulatory activity as potential therapeutic options against neurodegenerative disorders. Of course, the proper use of these compounds depends on considering their toxicity/safety profile and pharmacokinetic characteristics as well as the clinical conditions of users.

Paeoniflorin Attenuates Oxidative Stress and Inflammation in Parkinson's Disease by Activating the HSF1-NRF1 Axis

This study is to explore the effects of paeoniflorin (PF) on oxidative stress (OS) and inflammation in Parkinson's disease (PD) via the HSF1-NRF1 axis. SH-SY5Y cells were pretreated with PF and induced with α-synuclein preformed fibrils (PFF), followed by gain- and loss-of-function assays. Afterward, detection was conducted on cell viability, mitochondrial membrane potential ([Formula: see text]m), and reactive oxygen species (ROS), cyclooxygenase (COX)-2, and inducible nitric oxide synthase (iNOS) levels. The binding of HSF1 to NRF1 promoter was evaluated. HSF1 and NRF1 expression was examined. Lastly, PD mouse models were established, followed by observation of the behavioral features of mice. Apoptosis; cleaved-Caspase 3, cleaved-Caspase 8, repulsive guidance molecule A (RGMa), GAP-43, and brain-derived neurotrophic factor (BDNF) expression; and superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), catalase (CAT), tumor necrosis factor (TNF)-α, interleukin (IL)-2, IL-6, and IL-10 levels were determined in mice and cells. HSF1 and NRF1 were downregulated, and HSF1 promoted NRF1 transcription and PF dose-dependently augmented HSF1 and NRF1 expression. PF dose-dependently reduced RGMa expression, ROS, MDA, TNF-α, IL-2, and IL-6 levels; mitigated apoptosis; and lowered cleaved-Caspase 3, cleaved-Caspase 8, COX-2, and iNOS expression while improving cell viability; increasing [Formula: see text]m, GAP-43, and BDNF expression; and raising SOD, GSH-Px, CAT, and IL-10 levels in PFF-induced SH-SY5Y cells. These effects were neutralized by HSF1 knockdown. In conclusion, PF dose-dependently activated the HSF1-NRF1 axis and alleviated OS and inflammation in PFF-treated mice, thereby impeding PD progression in mice.

Association of plasma neurofilament light chain and Lipoprotein-related phospholipase A2 with motor subtypes of Parkinson's disease

Neurofilament light chain (NfL) levels were reliable biomarkers of neurodegeneration in Parkinson's disease (PD). Lipoprotein-related Phospholipase A2(Lp-PLA2) levels have also been increasingly studied in PD. We aimed to explore the association of plasma NfL and Lp-PLA2 with the diagnosis, motor subtypes and disease severity of PD. Plasma NfL and Lp-PLA2 were assayed separately in 106 participants (74 PD and 32 healthy controls, HC). The motor subtypes of PD were classified according to the MDS-UPDRS components, and motor and non-motor manifestations of patients were also evaluated. Subsequently, correlation analyses were performed. The plasma NfL levels were higher in the PD than HC, and were positively correlated with age, UPDRS II, UPDRS III and the modified Hoehn and Yahr staging scale (H&Y stage) in the PD. Moreover, plasma Lp-PLA2 levels were lower in the PD than HC, and were positively correlated with Parkinson's Disease Quality of Life Questionnaire (PDQ-39) in the PD. For further distinguishing tremor-dominant (TD) from postural instability and gait difficulty-dominant (PIGD), plasma Lp-PLA2 levels were higher in the TD than PIGD, but there was no significant difference in NfL. plasma Lp-PLA2 levels were positively correlated with UPDRS I, Hamilton Anxiety Rating Scale (HAMA) and PDQ-39 in the TD. These resultssuggest that NfL and Lp-PLA2 may be potential biomarkers for the diagnosis of PD. We first demonstrated the potential utility of plasma Lp-PLA2 in differentiating motor subtypes. These findings deserve further evidence in larger PD cohorts.

Atractylenolide-I Attenuates MPTP/MPP+‑Mediated Oxidative Stress in Parkinson's Disease Through SIRT1/PGC‑1α/Nrf2 Axis

Parkinson's disease (PD) is typically marked by motor dysfunction accompanied by loss of dopaminergic (DA) neurons and aggravated oxidative stress in the substantia nigra pars compacta (SNpc). Atractylenolide-I (ATR-I) is a potent antioxidant sesquiterpene with neuroprotective properties. However, whether ATR-I plays a neuroprotective role against oxidative stress in PD remains unclear. The objective of this study was to explore the mechanism of antioxidant action of ATR-I in PD models both in vivo and in vitro. Here, we show that ATR-I alleviated motor deficits in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mice. Moreover, ATR-I treatment effectively reduced DA neuron loss and increased tyrosine hydroxylase expression in the SNpc of MPTP-induced mice. Additionally, ATR-I inhibited oxidative stress (as manifested by elevated superoxide dismutase and glutathione peroxidase activities, and reduced malondialdehyde content) in MPTP-induced mice and attenuated reactive oxygen species levels in 1-methyl-4-phenylpyridinum (MPP+)-treated SH-SY5Y cells. Finally, ATR-I upregulated expressions of silent information regulator 1 (SIRT1), peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), NF-E2-related factor-2 (Nrf2), and heme oxygenase-1 in MPTP-induced mice and MPP+-treated SH-SY5Y cells, but had little effect on these factors in the presence of the SIRT1 inhibitor EX527. Taken together, these findings indicated that the important antioxidant role of ATR-I in MPTP/MPP+-mediated oxidative stress and the pathogenesis of PD through the SIRT1/PGC-1α/Nrf2 axis, highlighting its potential as a therapeutic option for PD.

Irisin's emerging role in Parkinson's disease research: A review from molecular mechanisms to therapeutic prospects

Parkinson's disease (PD), a neurodegenerative disorder characterized by impaired motor function, is typically treated with medications and surgery. However, recent studies have validated physical exercise as an effective adjunct therapy, significantly improving both motor and non-motor symptoms in PD patients. Irisin, a myokine, has garnered increasing attention for its beneficial effects on the nervous system. Research has shown that irisin plays a crucial role in regulating metabolic balance, optimizing autophagy, maintaining mitochondrial quality, alleviating oxidative stress and neuroinflammation, and regulating cell death-all processes intricately linked to the pathogenesis of PD. This review examines the mechanisms through which irisin may counteract PD, provides insights into its biological effects, and considers its potential as a target for therapeutic strategies.

SHANK2-AS3: A potential biomarker for Parkinson's disease and its role in neuronal apoptosis via NF-κB signaling in SH-SY5Y cells

Parkinson's disease (PD) is a progressive neurodegenerative disorder primarily driven by the degeneration of dopaminergic neurons, manifesting as hallmark symptoms such as muscle rigidity, tremors, and motor dysfunction, all of which severely compromise patients' quality of life. Increasing evidence highlights the critical role of long non-coding RNAs (lncRNAs) in PD pathogenesis. However, the specific involvement of SHANK2-AS3 in PD remains unclear. By reanalyzing the dysregulated lncRNAs from the GSE22491 dataset, we identified a significant upregulation of SHANK2-AS3 in PD patients compared to healthy controls. This finding was further validated in a new cohort of PD patients, where SHANK2-AS3 expression was notably elevated in peripheral blood samples. Additionally, we observed a marked increase in SHANK2-AS3 expression in MPTP-treated SH-SY5Y cells, a commonly used in vitro PD model. Functional assays demonstrated that SHANK2-AS3 knockdown attenuated MPTP-induced apoptosis, reduced reactive oxygen species (ROS) accumulation, and improved mitochondrial function. In contrast, SHANK2-AS3 overexpression exacerbated neuronal apoptosis. RNA sequencing and Western blot analyses revealed that the NF-κB signaling pathway is involved in SHANK2-AS3-mediated neuronal apoptosis. In summary, our findings suggest that SHANK2-AS3 plays a critical role in PD pathogenesis and represents a potential therapeutic target for mitigating neuronal damage in PD.

Randomly methylated β-cyclodextrin improves water - solubility, cellular protection and mucosa permeability of idebenone

Neurodegenerative diseases such as Alzheimer's are very common today. Idebenone (IDE) is a potent antioxidant with good potential for restoring cerebral efficiency in cases of these and other medical conditions, but a serious drawback for the clinical use of IDE in neurological disorders lies in its scarce water solubility, which greatly inhibits its bioavailability. In this work, we prepared the inclusion complex of IDE with randomly methylated β-cyclodextrin (RAMEB), resulting in improved water solubility of the included drug; then its in vitro biological activity and ex vivo permeability was evalutated. The solid complex was characterized through FT-IR spectroscopy, Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC). A 78-fold improvement of the solubility of IDE in water resulted, together with a strong 1:1 host-guest interaction (association constant of 12630 M-1), and dissolution of the complex within 15 min, all evidenced during the in-solution studies. Biological in vitro studies were then performed on differentiated human neuroblastoma cells (SH-SY5Y) subjected to oxidative stress. Pretreatment with IDE/RAMEB positively affected cell viability, promoted the nuclear translocation of Nrf2, and increased the levels of GSH as well as those of the endogenous antioxidant enzymes Mn-SOD and HO-1. Lastly, the complexation significantly improved the permeation of IDE through isolated rat nasal mucosa.