Treatment Of Parkinson's Disease Research Articles

Immunomodulator-Derived Nanoparticles Induce Neuroprotection and Regulatory T Cell Action to Alleviate Parkinsonism.

Post-translational modification, mitochondrial abruptions, neuroinflammation, and α-synuclein (α-Syn) aggregation are considered as major causes of Parkinson's disease (PD) pathogenesis. The recent literature highlights neuroimmune cross talk and the negative role of immune effector T (Teff) and positive regulation by regulatory T (Treg) cells in PD treatment. Herein, a strategy to endow Treg action paves the path for development of PD treatment. Thus, we explored the neuroprotective efficiency of the immunomodulator and PP2A (protein phosphatase 2) activator, FTY720 nanoparticles in in vivo experimental PD models. Repurposing of FTY720 for PD is known due to its protective effect by reducing PD and its camouflaged role in endowing EZH2-mediated epigenetic regulation of PD. EZH2-FOXP3 interaction is necessary for the neuroprotective Treg cell activity. Therefore, we synthesized FTY720 nanoparticles to improve FTY720 protective efficacy in an in vivo PD model to explore the PP2A mediated signaling. We confirmed the formation of FTY720NPs, and the results of the behavioral and protein expression study showed the significant neuroprotective efficiency of our nanoformulations. In the exploration of neuroprotective mechanism, several lines of evidence confirmed FTY720NPs mediated induction of PP2A/EZH2/FOXP3 signaling in the induction of Treg cells effect in in vivo PD treatment. In summary, our nanoformulations have novel potential to alleviate PD by inducing PP2A-induced epigenetic regulation-mediated neuroimmunomodulation at the clinical setup.

Rasagiline Exerts Neuroprotection towards Oxygen-Glucose-Deprivation/Reoxygenation-Induced GAPDH-Mediated Cell Death by Activating Akt/Nrf2 Signaling.

Rasagiline (Azilect®) is a selective monoamine oxidase B (MAO-B) inhibitor that provides symptomatic benefits in Parkinson's disease (PD) treatment and has been found to exert preclinical neuroprotective effects. Here, we investigated the neuroprotective signaling pathways of acute rasagiline treatment for 22 h in PC12 neuronal cultures exposed to oxygen-glucose deprivation (OGD) for 4 h, followed by 18 h of reoxygenation (R), causing 40% aponecrotic cell death. In this study, 3-10 µM rasagiline induced dose-dependent neuroprotection of 20-80%, reduced the production of the neurotoxic reactive oxygen species by 15%, and reduced the nuclear translocation of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) by 75-90%. In addition, 10 µM rasagiline increased protein kinase B (Akt) phosphorylation by 50% and decreased the protein expression of the ischemia-induced α-synuclein protein by 50% in correlation with the neuroprotective effect. Treatment with 1-5 µM rasagiline induced nuclear shuttling of transcription factor Nrf2 by 40-90% and increased the mRNA levels of the antioxidant enzymes heme oxygenase-1, (NAD (P) H- quinone dehydrogenase, and catalase by 1.8-2.0-fold compared to OGD/R insult. These results indicate that rasagiline provides neuroprotection to the ischemic neuronal cultures through the inhibition of α-synuclein and GAPDH-mediated aponecrotic cell death, as well as via mitochondrial protection, by increasing mitochondria-specific antioxidant enzymes through a mechanism involving the Akt/Nrf2 redox-signaling pathway. These findings may be exploited for neuroprotective drug development in PD and stroke therapy.

Delivery of CDNF by AAV-mediated gene transfer protects dopamine neurons and regulates ER stress and inflammation in an acute MPTP mouse model of Parkinson’s disease

Cerebral dopamine neurotrophic factor (CDNF) and its close structural relative, mesencephalic astrocyte-derived neurotrophic factor (MANF), are proteins with neurotrophic properties. CDNF protects and restores the function of dopamine (DA) neurons in rodent and non-human primate (NHP) toxin models of Parkinson’s disease (PD) and therefore shows promise as a drug candidate for disease-modifying treatment of PD. Moreover, CDNF was found to be safe and to have some therapeutic effects on PD patients in phase 1/2 clinical trials. However, the mechanism underlying the neurotrophic activity of CDNF is unknown. In this study, we delivered human CDNF (hCDNF) to the brain using an adeno-associated viral (AAV) vector and demonstrated the neurotrophic effect of AAV-hCDNF in an acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. AAV-hCDNF resulted in the expression of hCDNF in the striatum (STR) and substantia nigra (SN), and no toxic effects on the nigrostriatal pathway were observed. Intrastriatal injection of AAV-hCDNF reduced motor impairment and partially alleviated gait dysfunction in the acute MPTP mouse model. In addition, gene therapy with AAV-hCDNF had significant neuroprotective effects on the nigrostriatal pathway and decreased the levels of interleukin 1beta (IL-1β) and complement 3 (C3) in glial cells in the acute MPTP mouse model. Moreover, AAV-hCDNF reduced C/EBP homologous protein (CHOP) and glucose regulatory protein 78 (GRP78) expression in astroglia. These results suggest that the neuroprotective effects of CDNF may be mediated at least in part through the regulation of neuroinflammation and the UPR pathway in a mouse MPTP model of PD in vivo.

DRD2 activation inhibits choroidal neovascularization in patients with Parkinson's disease and age-related macular degeneration.

Neovascular age-related macular degeneration (nAMD) remains a major cause of visual impairment and puts considerable burden on patients and health care systems. L-DOPA-treated Parkinson Disease (PD) patients have been shown to be partially protected from nAMD, but the mechanism remains unknown. Using murine models, combining 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD and laser-induced nAMD, standard PD treatment of L-DOPA/DOPA-decarboxylase inhibitor, or specific dopamine receptor inhibitors, we here demonstrate that L-DOPA treatment-induced increase of dopamine mediated dopamine receptor D2 (DRD2) signaling inhibits choroidal neovascularization independently of MPTP-associated nigrostriatal pathway lesion. Analyzing a retrospective cohort of more than two hundred thousand nAMD patients receiving anti-VEGF treatment from the French nationwide insurance database, we show that DRD2-agonist treated (PD) patients have a significantly delayed age of onset for nAMD (81.4 (±7.0) vs 79.4 (±8.1) years old, respectively, p<0.0001) and reduced need for anti-VEGF therapies (-0.6 injections per 100 mg/day daily dose of DRD2 agonists the second year of treatment), similar to the L-DOPA treatment. While providing a mechanistic explanation for an intriguing epidemiological observation, our findings suggest that systemic DRD2 agonists might constitute an adjuvant therapy to delay and reduce the need for anti-VEGF therapy in nAMD patients.

An overview of the role of monoamine oxidase-B in Parkinson’s disease: implications for neurodegeneration and therapy

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by both non-motor and motor symptoms, due to the loss of dopamine-producing neurons in the brain. Monoamine oxidase-B (MAO-B) inhibitors are essential in the treatment of PD, as they increase dopamine levels and could potentially slow down the progression of the disease. MAO-B inhibitors block the ability of the enzyme to degrade dopamine in the brain. MAO-B inhibitors work by inhibiting this enzyme, which raises dopamine levels and helps reduce motor symptoms, such as akinesia and stiffness in the muscles. In addition to their impact on dopamine levels, MAO-B inhibitors may possess neuroprotective properties. Research indicates that these inhibitors can shield neurons from the harmful byproducts of dopamine breakdown, such as dihydroxy acetaldehyde and hydrogen peroxide. This neuroprotective effect could potentially slow the progression of PD and protect against neuronal damage. MAO-B inhibitors are effective in treating both advanced and early stages of PD. They are recommended as initial treatments for individuals with early PD and can also be used as supplementary therapy in advanced PD to assist in managing motor complications. Additionally, MAO-B inhibitors have shown promise for the treatment of non-motor symptoms of PD, such as fatigue and sleep disturbances. MAO-B inhibitors are an important class of drugs for the treatment of PD, offering both symptomatic relief and potential disease-modifying effects. The goal of ongoing research and development of MAO-B inhibitors is to enhance their safety and selectivity profiles, which could lead to improved treatment approaches for PD and other neurodegenerative disorders.

Honey and levodopa comparably preserved substantia nigra pars compacta neurons through the modulation of nuclear factor erythroid 2-related factor 2 signaling pathway in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinson's disease model.

Parkinson's disease (PD) affects about 8.5 million individuals worldwide. Oxidative and inflammatory cascades are implicated in the neurological sequels, that are mostly unresolved in PD treatments. However, proper nutrition offers one of the most effective and least costly ways to decrease the burden of many diseases and their associated risk factors. Moreover, prevention may be the best response to the progressive nature of PD, thus, the therapeutic novelty of honey and levodopa may be prospective. This study aimed to investigate the neuroprotective role of honey and levodopa against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced oxidative stress. Fifty-four adult male Swiss mice were divided into control and PD model groups of 27 mice. Each third of the control mice either received phosphate buffered saline, honey, or levodopa for 21 days. However, each third of the PD models was either pretreated with honey and levodopa or not pretreated. Behavioral studies and euthanasia were conducted 2 and 8 days after MPTP administration respectively. The result showed that there were significantly (P<0.05) higher motor activities in the PD models pretreated with the honey as well as levodopa. furthermore, the pretreatments protected the midbrain against the chromatolysis and astrogliosis induced by MPTP. The expression of antioxidant markers (glutathione [GSH] and nuclear factor erythroid 2-related factor 2 [Nrf2]) was also significantly upregulated in the pretreated PD models. It is thus concluded that honey and levodopa comparably protected the substantia nigra pars compacta neurons against oxidative stress by modulating the Nrf2 signaling molecule thereby increasing GSH level to prevent MPTP-induced oxidative stress.

A novel compound alleviates oxidative stress via PKA/CREB1-mediated DJ-1 upregulation.

Oxidative stress is one of the major culprits causing dopaminergic neuron loss in Parkinson's disease (PD). DJ-1 is a protein with multiple actions against oxidative stress, apoptosis, neuroinflammation, etc. DJ-1 expression is decreased in sporadic PD, therefore increasing DJ-1 expression might be beneficial in PD treatment. However, drugs known to upregulate DJ-1 are still lacking. In this study, we identified a novel DJ-1-elevating compound called ChemJ through luciferase assay-based high-throughput compound screening in SH-SY5Y cells and confirmed that ChemJ upregulated DJ-1 in SH-SY5Y cell line and primary cortical neurons. DJ-1 upregulation by ChemJ alleviated MPP+-induced oxidative stress. In exploring the underlying mechanisms, we found that the transcription factor CREB1 bound to DJ-1 promoter and positively regulated its expression under both unstressed and 1-methyl-4-phenylpyridinium-induced oxidative stress conditions and that ChemJ promoted DJ-1 expression via activating PKA/CREB1 pathway in SH-SY5Y cells. Our results demonstrated that ChemJ alleviated the MPP+-induced oxidative stress through a PKA/CREB1-mediated regulation of DJ-1 expression, thus offering a novel and promising avenue for PD treatment.

IRE1/JNK Is the Leading UPR Pathway in 6-OHDA-Induced Degeneration of Differentiated SH-SY5Y Cells.

Parkinson's disease (PD) is a neurodegenerative disorder which affects dopaminergic neurons of the midbrain. Accumulation of α-synuclein or exposure to neurotoxins like 6-hydroxydopamine (6-OHDA) induces endoplasmic reticulum (ER) stress along with the unfolded protein response (UPR), which executes apoptosis via activation of PERK/CHOP or IRE1/JNK signaling. The present study aimed to determine which of these pathways is a major contributor to neurodegeneration in an 6-OHDA-induced in vitro model of PD. For this purpose, we have applied pharmacological PERK and JNK inhibitors (AMG44 and JNK V) in differentiated SH-SY5Y cells exposed to 6-OHDA. Inhibition of PERK and JNK significantly decreased genotoxicity and improved mitochondrial respiration, but only JNK inhibition significantly increased cell viability. Gene expression analysis revealed that the effect of JNK inhibition was dependent on a decrease in MAPK10 and XBP1 mRNA levels, whereas inhibition of either PERK or JNK significantly reduced the expression of DDIT3 mRNA. Western blot has shown that JNK inhibition strongly induced the XBP1s protein, and inhibition of each pathway attenuated the phosphorylation of eIF2α and JNK, as well as the expression of CHOP. Collectively, our data suggests that targeting the IRE1/JNK pathway of the UPR is a more effective option for PD treatment as it simultaneously affects more than one pro-apoptotic pathway.

Continuous Subcutaneous Foslevodopa-Foscarbidopa in Parkinson's Disease: A Mini-Review of Current Scope and Future Outlook.

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by motor and non-motor symptoms, primarily because of the impairment of dopaminergic neurons. Long-term use of levodopa, the standard PD treatment, often results in fluctuating therapeutic effects and dyskinesia, necessitating alternative therapies. This review aims to synthesize current insights and clinical experiences with foslevodopa-foscarbidopa, focusing on its pharmacokinetics, efficacy, and safety profile, to evaluate its potential in transforming PD therapy. A systematic literature search was conducted up to November 2023 using databases PubMed, Web of Science, and Cochrane Library. The search yielded eight eligible articles, including pharmacological studies, case reports, observational studies, and controlled trials. No language restrictions were applied. Foslevodopa and foscarbidopa, as prodrugs of levodopa and carbidopa, exhibited excellent chemical stability and solubility, facilitating continuous subcutaneous infusion. Clinical trials demonstrated that these prodrugs maintain stable levodopa levels, thereby addressing the limitations of oral levodopa therapy. Phase 1 and 3 studies indicated significant improvements in motor function and quality of life in advanced PD patients. However, a higher incidence of treatment-emergent adverse events, mainly infusion site reactions, was observed compared to oral therapies. Foslevodopa-foscarbidopa emerges as a promising alternative for advanced PD treatment, offering sustained symptom control. Its efficacy in managing motor fluctuations and dyskinesia makes it a viable option in the PD therapeutic spectrum. Future research should focus on long-term safety, economic impact, and broader accessibility. Foslevodopa-foscarbidopa is now commercially distributed in many countries in Europe and in Japan.

Analysis of the use of deep brain stimulation in the treatment of Parkinson's disease

The central question of this study was the Analysis of deep brain stimulation (DBS) in the treatment of Parkinson's disease. The need to more deeply understand the benefits and limitations of DBS, especially given its increasing use as the standard treatment for advanced Parkinson's patients, justified this research. Detailed analysis of clinical outcomes and improvements in quality of life provided by DBS could offer valuable information for optimizing treatment protocols and clinical decision-making. This study aimed to address these issues through a comprehensive review of the existing literature, analysis of clinical data, and evaluation of best practices for DBS implementation in Parkinson's disease treatment. The methodology consisted of a qualitative literature review, utilizing sources such as Scielo, Google Scholar, scientific journals, and academic repositories. Relevant studies published in Portuguese, English, and Spanish over the last ten years were included. Inclusion and exclusion criteria ensured the selection of high-quality studies focused on the efficacy of DBS in treating Parkinson's disease. The results demonstrated significant benefits of DBS in improving both motor and non-motor symptoms, with DBS showing superior efficacy compared to other treatments. The study concluded that DBS is a highly effective therapeutic approach for Parkinson's disease, offering substantial improvements in patient quality of life and symptom management, highlighting the need for further research to optimize this treatment modality.

Identification of novel LRRK2 inhibitors by structure-based virtual screening and alchemical free energy calculation.

The Leucine-rich repeat kinase 2 (LRRK2) target has been identified as a promising drug target for Parkinson's disease (PD) treatment. This study focuses on optimizing the activity of LRRK2 inhibitors using alchemical relative binding free energy (RBFE) calculations. Initially, we assessed various free energy calculation methods across different LRRK2 kinase inhibitor scaffolds. The results indicate that alchemical free energy calculations are promising for prospective predictions on LRRK2 inhibitors, especially for the aminopyrimidine scaffold with an RMSE of 1.15 kcal mol-1 and Rp of 0.83. Following this, we optimized a potent LRRK2 kinase inhibitor identified from previous virtual screenings, featuring a novel scaffold. Guided by RBFE predictions using alchemical methods, this optimization led to the discovery of compound LY2023-001. This compound, with a [1,2,4]triazolo[5,6-b]indole scaffold, exhibited enhanced inhibitory activity against G2019S LRRK2 (IC50 = 12.9 nM). Molecular dynamics (MD) simulations revealed that LY2023-001 formed stable hydrogen bonds with Glu1948, and Ala1950 in the G2019S LRRK2 protein. Additionally, its phenyl substituents engage in strong electrostatic interactions with Lys1906 and van der Waals interactions with Leu1885, Phe1890, Val1893, Ile1933, Met1947, Leu1949, Leu2001, Ala2016, and Asp2017. Our findings underscore the potential of computational methods in the successful optimization of small molecules, offering important insights for the development of novel LRRK2 inhibitors.

Modulating efficient differentiation of neural stem cells into neurons by using plasmonic nanoparticles and the NIR II irradiation to boost therapy of Parkinson’s disease

Progressive loss of dopaminergic neurons is the primary pathological feature of Parkinson's disease (PD), which causes severe cognitive and motor dysfunction. In this context, transplantation of neural stem cells (NSCs) is the most promising approach to supply new dopaminergic neurons for the treatment of PD, which faces the challenge of precisely controlling the differentiation direction of NSCs. Herein, we report the efficient differentiation of NSCs into neurons boosted by the joint use of Cu2-xSe nanoparticles (CS NPs) with the second near-infrared (NIR-II) laser irradiation. We reveal the mechanism of neuronal differentiation of NSCs and find that the voltage-gated calcium channels (VGCC) of NSCs can be opened under the stimulation of CS NPs and NIR-II laser irradiation to trigger Ca2+/CaMK/CREB/c-Fos signaling pathway, which promotes the neural differentiation and survival. More importantly, when a mixture of CS NPs and NSCs was injected into the damaged striatum of 6-hydroxydopamine(6-OHDA)-induced PD mice and then irradiated with an external 1064 nm NIR-II laser, the NSCs were efficiently differentiated into dopaminergic neurons to effectively repair the damaged neural circuits in the nigra-striatum and ameliorate the motor disorders and anxiety of PD mice. These findings demonstrate the feasibility and importance of precise modulation of directional differentiation of NSCs into matured functional neurons in vivo and in vitro through advanced functional nanoparticles and nanotechnology, which offers a promising approach for the treatment of PD and other neurodegenerative diseases.

Fostering Inclusivity in Research Engagement for Underrepresented Populations in Parkinson's Disease: The FIRE-UP PD study

BackgroundMembers of vulnerable populations are underrepresented in Parkinson's disease (PD) research. A complex web of research barriers perpetuates this gap. Community-based research methods are one approach to addressing this issue. The present PD study was designed to examine the effectiveness of community-based interventions to overcome barriers and increase research participation among underrepresented groups (URGs). MethodsEight study sites across the US were selected and paired based on proposed interventions with specific URGs. Surveys assessed knowledge and attitudes toward PD research. Finally, researchers examined whether the present study affected recruitment to Fox Insight, an online PD research study also recruiting at each site. ResultsIn total, 474 participants were recruited. At post-intervention for the FIRE-UP PD Study, recruitment increased significantly in intervention compared to control sites among Black and African American non-Hispanic/Latino populations (p = 0.003), White Hispanic/Latino (p = 0.003) populations, and Not Listed Hispanic/Latino populations (p < 0.001) as well as those with an educational attainment of a high school diploma/General Education Diploma (GED) (p = 0.009), and an income <$20,000 (p = 0.005) or between $20,000–$34,999 (p < 0.001). Study surveys measuring changes in awareness and attitudes toward PD research had mixed results. In Fox Insight, 181 participants were passively recruited with a shift toward more diverse participant demographics. ConclusionResearch participation demographics reflective of the general population are critical to PD investigation and treatment. The FIRE-UP PD Study showed the effectiveness of localized community engagement strategies in increasing URG recruitment to PD research. Therefore, further PD research employing community-based methods to improve diverse participant recruitment is needed.

Deep Brain Stimulation of the Subthalamic Nucleus vs. Globus Pallidus Internus in the Treatment of Parkinson’s Disease: A Systematic Review

Abstract Background Parkinson’s disease (PD) is a very common debilitating disease especially in the elderly population. Bilateral stimulation of the subthalamic nucleus or the globus pallidus internus provides significant motor benefits for patients with advanced Parkinson’s disease, while reducing dyskinesia and motor fluctuation. High frequency stimulation of the STN and the GPi is relatively safe. The effects are stable even after 1 year of stimulation. Aim of the Work The primary goal of the current review is to compare the efficacy of using the Subthalamic Nucleus (STN) vs. the Globus Pallidus Internus (GPi) as the primary target for Deep Brain Stimulation (DBS) in the treatment of Parkinson disease (PD); in terms of improved motor function measured using the Unified Parkinson's Disease Rating Scale (UPDRS), psychiatric symptoms, rate of reduction of medication, and complications. This will be done through a systematic review of literature addressing this research question. Patients and Methods In this Review, the authors are aiming at the analysis of the collective outcomes from studies comparing bilateral deep brain stimulation of the Subthalamic Nucleus and the Globus Pallidus Internus in the management of idiopathic Parkinson’s disease. The following electronic databases were searched for included articles: PubMed, Google Scholar, EMBASE, Science Direct, Cochrane database of systematic reviews, using the keywords “Parkinson’s disease – treatment – management – deep brain stimulation – subthalamic – globus pallidus internus” in different combinations. Also, manual search were conducted for reference lists of included articles. Limiting the search in English. The information sources previously mentioned were searched from 2000 to 2021. Results A total of 594 patients underwent STN-DBS, with a mean change in total UPDRSIII score of 3.26 on medication and 25.04 off medication. A total of 446 patients underwent GPi-DBS, with a mean change in total UPDRSIII score of 4.75 on medication and 19.31 off medication. There was a higher change for GPi on medication that was statistically significant with a p value (˂0.001), while off medication STN caused a higher change that was also statistically significant with a p value (˂0.001). We observed a statistically significant higher average improvement in ADLs after STN-DBS than GPi, however, non- motor function improvements were greater after GPi DBS than STN DBS. Conclusion Based on our systematic review and other available data in the literature, the STN may be the preferred target for DBS in consideration of motor function improvement, medication reduction, and economic efficiency, although GPI stimulation has some advantages in terms of mood and cognition. Treatment decisions should be individualized and based on patients’ specific symptoms and expectations. Additional well-designed multicenter clinical trials that can minimize bias are needed, especially for evaluation of the long-term outcomes of the two stimulation targets.

547 Creation of a Machine Learning Model to Predict Cognitive Outcomes Post Deep Brain Stimulation Surgery for Parkinson’s Disease

Abstract Background Parkinson’s disease (PD) is the second most common neurodegenerative disorder and continues to affect an increasingly large portion of the world’s population. Limitations of the medical treatment of PD with levodopa have led to deep brain stimulation (DBS) therapy being used to alleviate symptoms in advanced PD patients. Despite its efficacy with motor symptoms of PD, DBS has been noted to lead to worsening of cognitive outcomes in a percentage of cases. There is currently no predictive model for individual patient cognitive outcomes post DBS. Aim The aim of this study is the creation of a machine learning (ML) model which can help facilitate decision making for clinicians regarding offering DBS to patients. ML has the potential to analyse multiple variables and produce a predictive model for neurocognitive outcomes. The volume of variables analysed by ML is beyond the remit of calculations that can be performed by individual medical professionals for each patient. Method This study used mild cognitive impairment (MCI) as the outcome, at six months post DBS surgery to measure neurocognitive impact. Clinical and radiomics variables were used to train the models. Results Two predictive models were successfully generated – random forest and logistic regression, which showed an accuracy of 0.87 and 0.74 respectively. Conclusions The study concluded that it is possible to use ML to generate a prediction model for outcomes post DBS. The model can help optimise the decision-making process behind offering DBS surgery to patients and lend insight into the possible causes of poor outcomes.

BL-918 activates PINK1/Parkin signaling pathway to ameliorate the progression of Parkinson’s disease

The pathogenesis of Parkinson’s disease (PD) has been associated with mitochondrial dysfunction. Given that the PINK1/Parkin pathway governs mitochondrial quality control by inducing mitophagy to remove damaged mitochondria, therapeutic approaches to activate PINK1/Parkin-mediated mitophagy have the potential in the treatment of PD. Here, we have identified a new small molecule, BL-918, as an inducer of mitophagy via activating the PINK1/Parkin pathway. BL-918 triggers PINK1 accumulation and Parkin mitochondrial translocation to initiate PINK1/Parkin-mediated mitophagy. We found that mitochondrial membrane potential and mitochondrial permeability transition (mPT) pore were involved in BL-918-induced PINK1/Parkin pathway activation. Moreover, we showed that BL-918 mitigated PD progression in MPTP-induced PD mice in a PINK1-dependent manner. Our results unravel a new activator of the PINK1/Parkin signaling pathway and provide a potential strategy for the treatment of PD and other diseases with dysfunctional mitochondria.

Rev-erbα regulate neurogenesis through suppression of Sox2 in neuronal cells to regenerate dopaminergic neurons and abates MPP+ induced neuroinflammation

Parkinson's disease is a progressive neurodegenerative disease that affects the motor and non-motor circuits of the brain. Currently, there are no promising therapeutic measures for Parkinson's disease, and most strategies designed to alleviate the Parkinson's disease are palliative. The dearth of therapeutic interventions in Parkinson's disease has driven attention in the search for targets that may augment dopamine secretion, promote differentiation towards dopaminergic neuronal lineage, or aid in neuroprotection from neuronal stress and inflammation, and prevent Parkinson's disease associated motor impairment and behavioural chaos.The study first reports that Rev-erbα plays an important role in regulating the differentiation of undifferentiated neuronal cells towards dopaminergic neurons through abating Sox2 expression in human SH-SY5Y cells. Rev-erbα directly binds to the human Sox2 promoter region and represses their expression to promote differentiation towards dopaminergic neurons. We have reported a novel mechanism of Rev-erbα which effectively abrogates 1-methyl-4-phenylpyridinium induced cytotoxicity, inflammation, and oxidative stress, exerted a beneficial effect on transmembrane potential, and suppressed apoptosis in the neuronal in vitro model of Parkinson's disease.Rev-erbα ligand SR9011 was observed to ease the disease severity in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine induced mouse model of Parkinson's disease. Rev-erbα alleviates the locomotor behavioural impairment, prevents cognitive decline and promotes motor coordination in mice. Administration of Rev-erbα ligand also helps in replenishing the dopaminergic neurons and abrogating the neurotoxin mediated toxicity in an in vitro and in vivo Parkinson's disease model.We conclude that Rev-erbα emerges as a moonlighting nuclear receptor that could be targeted in the treatment and alleviation of Parkinson disease.

Neuroprotective efficacy of the glucocorticoid receptor modulator PT150 in the rotenone mouse model of Parkinson’s disease

Parkinson's disease (PD) is the most common neurodegenerative movement disorder worldwide. Current treatments for PD largely center around dopamine replacement therapies and fail to prevent the progression of pathology, underscoring the need for neuroprotective interventions. Approaches that target neuroinflammation, which occurs prior to dopaminergic neuron (DAn) loss in the substantia nigra (SN), represent a promising therapeutic strategy. The glucocorticoid receptor (GR) has been implicated in the neuropathology of PD and modulates numerous neuroinflammatory signaling pathways in the brain. Therefore, we investigated the neuroprotective effects of the novel GR modulator, PT150, in the rotenone mouse model of PD, postulating that inhibition of glial inflammation would protect DAn and reduce accumulation of neurotoxic misfolded ⍺-synuclein protein. C57Bl/6 mice were exposed to 2.5 mg/kg/day rotenone by intraperitoneal injection for 14 days. Upon completion of rotenone dosing, mice were orally treated at day 15 with 30 mg/kg/day or 100 mg/kg/day PT150 in the 14-day post-lesioning incubation period, during which the majority of DAn loss and α-synuclein (α-syn) accumulation occurs. Our results indicate that treatment with PT150 reduced both loss of DAn and microgliosis in the nigrostriatal pathway. Although morphologic features of astrogliosis were not attenuated, PT150 treatment promoted potentially neuroprotective activity in these cells, including increased phagocytosis of hyperphosphorylated α-syn. Ultimately, PT150 treatment reduced the loss of DAn cell bodies in the SN, but not the striatum, and prohibited intra-neuronal accumulation of α-syn. Together, these data indicate that PT150 effectively reduced SN pathology in the rotenone mouse model of PD.

Oxidative Stress and Dopaminergic Metabolism: A Major PD Pathogenic Mechanism and Basis of Potential Antioxidant Therapies

Reactive oxygen species (ROS)-induced oxidative stress triggers the vicious cycle leading to the degeneration of dopaminergic neurons in the nigra pars compacta. ROS produced during the metabolism of dopamine is immediately neutralized by the endogenous antioxidant defense system (EADS) under physiological conditions. Aging decreases the vigilance of EADS and makes the dopaminergic neurons more vulnerable to oxidative stress. As a result, ROS left over by EADS oxidize the dopamine-derived catechols and produces a number of reactive dopamine quinones, which are precursors to endogenous neurotoxins. In addition, ROS causes lipid peroxidation, uncoupling of the electron transport chain, and DNA damage, which lead to mitochondrial dysfunction, lysosomal dysfunction, and synaptic dysfunction. The mutations in genes such as DNAJC6, SYNJ1, SH3GL2, LRRK2, PRKN, and VPS35 caused by ROS have been associated with synaptic dysfunction and the pathogenesis of Parkinson’s disease (PD). The available drugs that are used against PD can only delay the progression of the disease, but they produce various side effects. Through their antioxidant activity, flavonoids can substantiate the EADS of dopaminergic neurons and disrupt the vicious cycle incepted by oxidative stress. In this review, we show how the oxidative metabolism of dopamine generates ROS and dopamine-quinones, which then exert unrestrained OS, causing mutations in several genes involved in the proper functioning of mitochondrion, synapse, and lysosome. Besides, we also present some examples of approved drugs used for the treatment of PD, therapies in the clinical trial phase, and an update on the flavonoids that have been tested to boost the EADS of dopaminergic neurons.

The involvement of Slc7a11/xCT related iron accumulation on acupuncture intervention in 6-OHDA-induced Parkinson rat

BackgroundAcupuncture plays a critical role for the treatment of patients with Parkinson's disease (PD), which is characterized by ferroptosis of dopaminergic neurons. It has been found that acupuncture can reduce iron accumulation. However, the mechanism of acupuncture therapy against PD by inhibiting ferroptosis remains unclear. ObjectivesTo investigate the potential mechanism of acupuncture on alleviating ferroptosis in 6-OHDA-induced PD rats. MethodsMale Sprague-Dawley rats were randomly divided into sham group, acupuncture group, and PD model group, with the PD model induced by 6-OHDA. The motor function of the rats was tested by the rotation test and suspension test, respectively. Immunohistochemistry and iron staining were performed to analyze nerve damage, and the effect of acupuncture on the accumulation of iron in the substantia nigra (SN). RNA-seq analysis in the SN of rats were performed to discover ferroptosis-related genes. Differentially expressed genes (DEGs) resulted from the acupuncture treatment were identified and were used for Gene Ontology (GO) function, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. A protein–protein interaction (PPI) network was constructed, and alternative splicing (AS) analysis of the transcriptome was performed. Western blot was used to detect the protein level change of Slc7a11/xCT. ResultsRotation test and suspension test indicated a positive effect of acupuncture on body weight gain and limb function. Perl's iron staining and ELISA test detected 6-OHDA induced iron accumulation in the SN and nerve damage, which was mitigated by acupuncture treatment. Acupuncture treatment brought about the differential expression of a total of 1088 genes in the SN of rats. GO and KEGG enrichment revealed that such DEGs were mainly associated with several key biological process (BP), cellular component (CC) and molecular function (MF) terms. These terms included collagen fibril organization, extracellular matrix organization, collagen trimer, extracellular matrix components, chemokine receptor binding and cargo receptor activity, etc. Additionally, the DEGs were found to be involved in pathways such as complement and coagulation. The PPI network of DEGs suggested a critical role of Slc7a11, which was further supported by an up-regulated Slc7a11/xCT protein level in the substantia nigra (SN) tissue of rats treated with acupuncture compared to their PD model counterparts (P = 0.045). ConclusionAcupuncture may prevent ferroptosis through Slc7a11/xCT as one of the targets in 6-OHDA-induced PD model and thereby could be promising for PD treatment.