Pivotal Role of Fyn Kinase in Parkinson's Disease and Levodopa-Induced Dyskinesia: a Novel Therapeutic Target?

Pre-clinical evidence for mitochondria as a therapeutic target for luteolin: A mechanistic view

Pre-clinical evidence indicates that mitochondria may be a therapeutic target for luteolin (3',4',5,7-tetrahydroxyflavone; LUT) in different conditions. LUT modulates mitochondrial physiology in in vitro, ex vivo, and in vivo experimental models. This flavone exerted mitochondria-related antioxidant and anti-apoptotic effects, stimulated mitochondrial fusion and fission, induced mitophagy, and promoted mitochondrial biogenesis in human and animal cells and tissues. Moreover, LUT modulated the activity of components of the oxidative phosphorylation (OXPHOS) system, improving the ability of mitochondria to produce adenosine triphosphate (ATP) in certain circumstances. The mechanism of action by which LUT promoted mitochondrial benefits and protection are not completely clear yet. Nonetheless, LUT is a potential candidate to be utilized in mitochondrial therapy in the future. In this work, it is explored the mechanisms of action by which LUT modulates mitochondrial physiology in different pre-clinical experimental models.

Modulation of Peripheral Mast Cell and Brain Microglia Axis via Kinase Inhibition

Background/Objectives: Kinase inhibition is a hot therapeutic strategy for several human diseases, including neurodegeneration. Tyrosine kinase c-KIT activates peripheral mast cells, while other kinases including Abelson (c-Abl) promotes autophagy and FYN mediates Tau phosphorylation. We synthesized a novel broad kinase inhibitor (BK40196) and investigated its effects on tau hyper-phosphorylation, cell loss, inflammation and behavior in transgenic rTg4510 and TgAPP (TgSwDI) mice. Methods: Drug synthesis and investigation of the pharmacokinetics and pharmacodynamics effects of BK40196 on behavior, protein levels, mast cells and microglial activity in vivo. Results: We synthesized a novel kinase inhibitor (BK40196) that exhibited high brain penetration and a potentially wide therapeutic dose. BK40196 is a dual c-KIT/c-Abl (Abelson) inhibitor but also displays binding affinity to other kinases, including fused in sarcoma (SRC) and FYN. BK40196 induces autophagy in vitro and limits the maturation of mast cells in vitro and in vivo. BK40196 significantly reduces the levels of hyper-phosphorylated tau and attenuates cell loss, while improving motor, cognitive and behavioral (anxiety) functions in models of neurodegeneration. BK40196 reduces microglial activity and the levels of brain tryptase in parallel with mast cell activation. Conclusions: BK40196 inhibits c-Kit and may play an important role in peripheral and central immunity via mast cells and microglia, respectively, and induces synergistic mechanisms through anti-inflammation and protein clearance that are mutually beneficial to alleviate neurodegenerative pathology. BK40196 is a potential candidate for the treatment of human tauopathies.

Unraveling the role of neuregulin-mediated astrocytes-OPCs axis in the pathogenesis of age-related macular degeneration and Parkinson's disease

Age-related macular degeneration (AMD) and Parkinson's disease (PD) are prevalent and debilitating conditions that lead to irreversible blindness and dyskinesia, respectively. Emerging evidences imply that retinal abnormalities may serve as early indicators for monitoring PD. This study endeavors to explore the complex interactions and focus on their shared molecular and pathological mechanisms. We employed a comprehensive approach by integrating single-cell RNA sequencing (scRNA-seq) datasets, obtained from dry AMD retinas and PD brain tissues, along with Weighted Gene Co-expression Network Analysis (WGCNA)-related computational analysis. Gene Set Enrichment Analysis (GSEA) was conducted to analyze PD-related genes within retinal ganglion cells in dry AMD. Cell-cell chat was utilized to predict intercellular communication and signaling pathways. Module eigengenes (MEs) were calculated to identify specific gene modules. Dysregulation of PALLD, FYN and ZMZ1 may lead to cell structural abnormalities, impaired mitochondrial functions, and increased susceptibility to neuroinflammation, contributing to the AMD and PD progression. Additionally, this study highlighted an astrocyte-oligodendrocyte precursor cell (OPCs) signaling axis mediated by Neuregulin (NRG), which is hypothesized to influence neuroinflammatory processes characteristic of dry AMD and PD pathogenesis. Notably, ME-salmon module associated with gene dysregulation exhibited a strong positive correlation with the ME-blue module, linked to neurodegenerative impairment, and the ME-yellow module, related to mitochondrial dysfunction. The comprehensive investigation on astrocytes-OPCs signaling axis, and the NRG signaling pathway advances our understanding of the intricate biological processes underpinning AMD and PD. This research underscores the critical importance about exploring glial-related cell interactions, providing valuable insights into potential novel therapeutic approaches for these complex diseases.

Neuroprotective thiazole sulfonamides against 6-OHDA-induced Parkinsonian model: in vitro biological and in silico pharmacokinetic assessments

The limitations of currently existing medications in delaying or halting the development of Parkinson's disease (PD) remain dramatically problematic, making it the second most prevalent neurodegenerative disorder. Moreover, it is expected that the number of PD cases will double within the next 30 years. Herein, to discover a novel neuroprotective therapeutic strategy, a series of multifunctional thiazole sulfonamides underwent preliminary assessment owing to their neuroprotective capabilities against 6-hydroxydopamine (6-OHDA)-induced damage in human neuronal SH-SY5Y cells. Pretreatment with novel synthetic hybrids, including 1, 2, and 8, significantly improved cell viability, reduced lactate dehydrogenase (LDH) leakage, prevented mitochondrial dysfunction, and mitigated intracellular oxidative stress. Insight molecular mechanisms and potential targets of these compounds were elucidated through their activation and binding interaction with sirtuin 1 (SIRT1), suggesting their influencing roles on relevant downstream cascades of PD. Furthermore, in silico pharmacokinetic analysis revealed the drug-likeness of these three hybrids, which are capable of being distributed into the central nervous system (CNS) with slight toxicity. Therefore, these novel neuroprotective thiazole sulfonamides are promising candidates for further development (i.e., in vivo and clinical trials) of effective PD therapy.

Identification of novel Kv1.3 channel-interacting proteins using proximity labelling in T-cells

Potassium channels regulate membrane potential, calcium flux, cellular activation and effector functions of adaptive and innate immune cells. The voltage-activated Kv1.3 channel is an important regulator of T cell-mediated autoimmunity and microglia-mediated neuroinflammation. Kv1.3 channels, via protein-protein interactions, are localized with key immune proteins and pathways, enabling functional coupling between K+ efflux and immune mechanisms. To gain insights into proteins and pathways that interact with Kv1.3 channels, we applied a proximity-labeling proteomics approach to characterize protein interactors of the Kv1.3 channel in activated T-cells. Biotin ligase TurboID was fused to either N or C termini of Kv1.3, stably expressed in Jurkat T cells and biotinylated proteins in proximity to Kv1.3 were enriched and quantified by mass spectrometry. We identified over 1,800 Kv1.3 interactors including known interactors (beta-integrins, Stat1) although majority were novel. We found that the N-terminus of Kv1.3 preferentially interacts with protein synthesis and protein trafficking machinery, while the C-terminus interacts with immune signaling and cell junction proteins. T-cell Kv1.3 interactors included 335 cell surface, T-cell receptor complex, mitochondrial, calcium and cytokine-mediated signaling pathway and lymphocyte migration proteins. 178 Kv1.3 interactors in T-cells also represent genetic risk factors of T cell-mediated autoimmunity, including STIM1, which was further validated using co-immunoprecipitation. Our studies reveal novel proteins and molecular pathways that interact with Kv1.3 channels in adaptive (T-cell) and innate immune (microglia), providing a foundation for how Kv1.3 channels may regulate immune mechanisms in autoimmune and neurological diseases.

Levodopa-induced dyskinesia: brain iron deposition as a new hypothesis

Parkinson's disease (PD) is a common neurodegenerative disease in the older adults. The main pathological change in PD is the degenerative death of dopamine (DA) neurons in the midbrain substantia nigra, which causes a significant decrease in the DA content of the striatum. However, the exact etiology of this pathological change remains unclear. Genetic factors, environmental factors, aging, and oxidative stress may be involved in the degenerative death of dopaminergic neurons in PD. Pharmacological treatment using levodopa (L-DOPA) remains the main treatment for PD. Most patients with PD consuming L-DOPA for a long time usually develop levodopa-induced dyskinesia (LID) after 6.5 years of use, and LID seriously affects the quality of life and increases the risk of disability. Recently, studies have revealed that cerebral iron deposition may be involved in LID development and that iron deposition has neurotoxic effects and accelerates disease onset. However, the relationship between cerebral iron deposition and LID remains unclear. Herein, we reviewed the mechanisms by which iron deposition may be associated with LID development, which are mainly related to oxidative stress, neuroinflammation, and mitochondrial and lysosomal dysfunction. Using iron as an important target, the search and development of safe and effective brain iron scavengers, and thus the alleviation and treatment of LID, has a very important scientific and clinical value, as well as a good application prospect.

Mechano-growth factor regulates periodontal ligament stem cell proliferation and differentiation through Fyn-RhoA-YAP signaling

BACKGROUND

Mechano-growth factor (MGF), which is a growth factor produced specifically in response to mechanical stimuli, with potential of tissue repair and regeneration. Our previous research has shown that MGF plays a crucial role in repair of damaged periodontal ligaments by promoting differentiation of periodontal ligament stem cells (PDLSCs). However, the molecular mechanism is not fully understood. This study aimed to investigated the regulatory effect of MGF on differentiation of PDLSCs and its molecular mechanism.

METHODS

Initially, we investigated how MGF impacts cell growth and differentiation, and the relationship with the activation of Fyn-p-YAPY357 and LATS1-p-YAPS127. Then, inhibitors were used to interfere Fyn phosphorylation to verify the role of Fyn-p-YAP Y357 signal after MGF stimulation; moreover, siRNA was used to downregulate YAP expression to clarify the function of YAP in PDLSCs proliferation and differentiation. Finally, after C3 was used to inhibit the RhoA expression, we explored the role of RhoA in the Fyn-p-YAP Y357 signaling pathway in PDLSCs proliferation and differentiation.

RESULTS

Our study revealed that MGF plays a regulatory role in promoting PDLSCs proliferation and fibrogenic differentiation by inducing Fyn-YAPY357 phosphorylation but not LATS1-YAP S127 phosphorylation. Moreover, the results indicated that Fyn could not activate YAP directly but rather activated YAP through RhoA in response to MGF stimulation.

CONCLUSION

The research findings indicated that the Fyn-RhoA-p-YAPY357 pathway is significant in facilitating the proliferation and fibrogenic differentiation of PDLSCs by MGF. Providing new ideas for the study of MGF in promoting periodontal regenerative repair.

Polybrominated diphenyl ethers isolated from the marine sponge Lendenfeldia chondrodes collected in Mayotte

CDK7 and FynB protein kinases have been recognized as relevant targets for cancer and brain diseases treatment due to their pivotal regulatory roles in cellular functions such as cell cycle and neural signal transduction. Several studies demonstrated that the inhibition of these proteins could be useful in altering the onset or progression of these diseases. Based on bioassay-guided approach, the extract of the marine sponge Lendenfeldia chondrodes (Thorectidae), which exhibited interesting kinase inhibitory activities, was fractionated. The investigation led to the isolation of five known 1-5 and one new 6 polybrominated diphenyl ethers (PBDEs). Their structure elucidation was established based on spectroscopic data (NMR and HRMS) and comparison with literature data.

The role of ACE2 in RAS axis on microglia activation in Parkinson's disease

BACKGROUND

The classic renin-angiotensin system (RAS) induces organ damage, while the ACE2/Ang-(1-7)/MasR axis opposes it. However, the role of ACE2 in the brain is unclear. We studied ACE2's role in the brain.

METHOD

We used male C57BL/6J (WT) mice, ACE2 knockout (KO) mice, and MPTP-induced mice. Behavioral tests confirmed successful modeling. We assessed the impact of ACE2 KO on the RAS axis and PD index, including ACE, ACE2, AT1, AT2, MasR, TH, α-syn, and Iba1. We investigated ACE2 and MasR's involvement in microglial activation via western blot and immunofluorescence. GSE10867 and GSE26532 datasets were used to analyze the effects of AT1 antagonists and in vitro PD models on microglia.

RESULT

Behavioral tests revealed that MPTP mice displayed motor deficits, depression, anxiety, and increased inflammatory markers in the SN and CPU, with reduced antioxidant capacity. ACE2 KO worsened these symptoms and exacerbated inflammation and oxidative stress. LPS-induced ACE2/MasR activation in BV2 cells demonstrated anti-inflammatory and neuroprotective effects by modulating microglial polarization. Antagonists inhibited microglial activation via inflammation and ROS processes.

CONCLUSION

The RAS axis regulates inflammation and oxidative stress to maintain CNS function, suggesting potential targets for neurologic disease treatment. Understanding microglial RAS activation can offer new therapeutic strategies.

Neuroinflammation and Dyskinesia: A Possible Causative Relationship?

Levodopa (L-DOPA) treatment represents the gold standard therapy for Parkinson's disease (PD) patients. L-DOPA therapy shows many side effects, among them, L-DOPA-induced dyskinesias (LIDs) remain the most problematic. Several are the mechanisms underlying these processes: abnormal corticostriatal neurotransmission, pre- and post-synaptic neuronal events, changes in gene expression, and altered plasticity. In recent years, researchers have also suggested non-neuronal mechanisms as a possible cause for LIDs. We reviewed recent clinical and pre-clinical studies on neuroinflammation contribution to LIDs. Microglia and astrocytes seem to play a strategic role in LIDs phenomenon. In particular, their inflammatory response affects neuron-glia communication, synaptic activity and neuroplasticity, contributing to LIDs development. Finally, we describe possible new therapeutic interventions for dyskinesia prevention targeting glia cells.

Unraveling the Genetic Landscape of Neurological Disorders: Insights into Pathogenesis, Techniques for Variant Identification, and Therapeutic Approaches

Genetic abnormalities play a crucial role in the development of neurodegenerative disorders (NDDs). Genetic exploration has indeed contributed to unraveling the molecular complexities responsible for the etiology and progression of various NDDs. The intricate nature of rare and common variants in NDDs contributes to a limited understanding of the genetic risk factors associated with them. Advancements in next-generation sequencing have made whole-genome sequencing and whole-exome sequencing possible, allowing the identification of rare variants with substantial effects, and improving the understanding of both Mendelian and complex neurological conditions. The resurgence of gene therapy holds the promise of targeting the etiology of diseases and ensuring a sustained correction. This approach is particularly enticing for neurodegenerative diseases, where traditional pharmacological methods have fallen short. In the context of our exploration of the genetic epidemiology of the three most prevalent NDDs-amyotrophic lateral sclerosis, Alzheimer's disease, and Parkinson's disease, our primary goal is to underscore the progress made in the development of next-generation sequencing. This progress aims to enhance our understanding of the disease mechanisms and explore gene-based therapies for NDDs. Throughout this review, we focus on genetic variations, methodologies for their identification, the associated pathophysiology, and the promising potential of gene therapy. Ultimately, our objective is to provide a comprehensive and forward-looking perspective on the emerging research arena of NDDs.

In Silico Screening and Molecular Dynamics Simulations against Tyrosine-protein Kinase Fyn Reveal Potential Novel Therapeutic Candidates for Bovine Papillomatosis

BACKGROUND

Decreased beef productivity due to papillomatosis has led to the development and identification of novel targets and molecules to treat the disease. Protein kinases are promising targets for the design of numerous chemotherapy drugs.

OBJECTIVE

This study aimed to screen and design new inhibitors of bovine Fyn, a protein kinase, using structure-based computational methods, such as molecular docking and molecular dynamics simulation (MDS).

METHODS

To carry out the molecular docking analysis, five ligands obtained through structural similarity between active compounds along with the cross-inhibition function between the ChEMBL and Drugbank databases were used. Molecular modeling was performed, and the generated models were validated using PROCHECK and Verify 3D. Molecular docking was performed using Autodock Vina. The complexes formed between Fyn and the three best ligands had their stability assessed by MDS. In these simulations, the complexes were stabilized for 100 ns in relation to a pressure of 1 atm, with an average temperature of 300 k and a potential energy of 1,145,336 kJ/m converged in 997 steps.

RESULTS

Docking analyses showed that all selected ligands had a high binding affinity with Fyn and presented hydrogen bonds at important active sites. MDS results support the docking results, as the ligand showed similar and stable interactions with amino acids present at the binding site of the protein. In all simulations, sorafenib obtained the best results of interaction with the bovine Fyn.

CONCLUSION

The results highlight the identification of possible bovine Fyn inhibitors; however, further studies are important to confirm these results experimentally.

Levodopa-induced dyskinesia: interplay between the N-methyl-D-aspartic acid receptor and neuroinflammation

Parkinson's disease (PD) is a common neurodegenerative disorder of middle-aged and elderly people, clinically characterized by resting tremor, myotonia, reduced movement, and impaired postural balance. Clinically, patients with PD are often administered levodopa (L-DOPA) to improve their symptoms. However, after years of L-DOPA treatment, most patients experience complications of varying severity, including the "on-off phenomenon", decreased efficacy, and levodopa-induced dyskinesia (LID). The development of LID can seriously affect the quality of life of patients, but its pathogenesis is unclear and effective treatments are lacking. Glutamic acid (Glu)-mediated changes in synaptic plasticity play a major role in LID. The N-methyl-D-aspartic acid receptor (NMDAR), an ionotropic glutamate receptor, is closely associated with synaptic plasticity, and neuroinflammation can modulate NMDAR activation or expression; in addition, neuroinflammation may be involved in the development of LID. However, it is not clear whether NMDA receptors are co-regulated with neuroinflammation during LID formation. Here we review how neuroinflammation mediates the development of LID through the regulation of NMDA receptors, and assess whether common anti-inflammatory drugs and NMDA receptor antagonists may be able to mitigate the development of LID through the regulation of central neuroinflammation, thereby providing a new theoretical basis for finding new therapeutic targets for LID.

Exploring the Role of ACE2 as a Connecting Link between COVID-19 and Parkinson's Disease

Coronavirus disease 2019 (COVID-19) is frequently accompanied by neurological manifestations such as headache, delirium, and epileptic seizures, whereas ageusia and anosmia may appear before respiratory symptoms. Among the various neurological COVID-19-related comorbidities, Parkinson's disease (PD) has gained increasing attention. Some cases of PD disease have been linked to COVID-19, and both motor and non-motor symptoms in Parkinson's disease patients frequently worsen following SARS-CoV-2 infection. Although it is still unclear whether PD increases the susceptibility to SARS-CoV-2 infection or whether COVID-19 increases the risk of or unmasks future cases of PD, emerging evidence sheds more light on the molecular mechanisms underlying the relationship between these two diseases. Among them, angiotensin-converting enzyme 2 (ACE2), a significant component of the renin-angiotensin system (RAS), seems to play a pivotal role. ACE2 is required for the entry of SARS-CoV-2 to the human host cells, and ACE2 dysregulation is implicated in the severity of COVID-19-related acute respiratory distress syndrome (ARDS). ACE2 imbalance is implicated in core shared pathophysiological mechanisms between PD and COVID-19, including aberrant inflammatory responses, oxidative stress, mitochondrial dysfunction, and immune dysregulation. ACE2 may also be implicated in alpha-synuclein-induced dopaminergic degeneration, gut-brain axis dysregulation, blood-brain axis disruption, autonomic dysfunction, depression, anxiety, and hyposmia, which are key features of PD.

Identification of immune signatures in Parkinson's disease based on co-expression networks

Parkinson's disease (PD) is a common neurodegenerative disease in middle-aged and elderly people, and there is less research on the relationship between immunity and PD. In this study, the protein-protein interaction networks (PPI) data, 2747 human immune-related genes (HIRGs), 2078 PD-related genes (PDRGs), and PD-related datasets (GSE49036 and GSE20292) were downloaded from the Human Protein Reference Database (HPRD), Amigo 2, DisGeNET, and Gene Expression Omnibus (GEO) databases, respectively. An immune- or PD-directed neighbor co-expressed network construction (IOPDNC) was drawn based on the GSE49036 dataset and HPRD database. Furthermore, a PD-directed neighbor co-expressed network was constructed. Modular clustering analysis was performed on the genes of the gene interaction network obtained in the first step to obtain the central core genes using the GraphWeb online website. The modules with the top 5 functional scores and the number of core genes greater than six were selected as PD-related gene modules. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of different module genes were performed. The single sample Gene Set Enrichment Analysis (ssGSEA) algorithm was used to calculate the immune cell infiltration of the PD and the normal samples. The quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) was performed to investigate the expression of module genes. An IOPDNC and PD-directed neighbor co-expressed network (PDNC network) were constructed. Furthermore, a total of 5 immune-PD modules were identified which could distinguish between PD and normal samples, and these module genes were strongly related to PD in protein interaction level or gene expression level. In addition, functional analysis indicated that module genes were involved in various neurodegenerative diseases, such as Alzheimer disease, Huntington disease, Parkinson disease, and Long-term depression. In addition, the genes of the 6 modules were significantly associated with these 4 differential immune cells (aDC cells, eosinophils, neutrophils, and Th2 cells). Finally, the result of qRT-PCR manifested that the expression of 6 module genes was significantly higher in normal samples than in PD samples. In our study, the immune-related genes were found to be strongly related to PD and might play key roles in PD.

Emerging Potential of the Phosphodiesterase (PDE) Inhibitor Ibudilast for Neurodegenerative Diseases: An Update on Preclinical and Clinical Evidence

Neurodegenerative diseases constitute a broad range of central nervous system disorders, characterized by neuronal degeneration. Alzheimer's disease, Parkinson's disease, amyolotrophic lateral sclerosis (ALS), and progressive forms of multiple sclerosis (MS) are some of the most frequent neurodegenerative diseases. Despite their diversity, these diseases share some common pathophysiological mechanisms: the abnormal aggregation of disease-related misfolded proteins, autophagosome-lysosome pathway dysregulation, impaired ubiquitin-proteasome system, oxidative damage, mitochondrial dysfunction and excessive neuroinflammation. There is still no effective drug that could halt the progression of neurodegenerative diseases, and the current treatments are mainly symptomatic. In this regard, the development of novel multi-target pharmaceutical approaches presents an attractive therapeutic strategy. Ibudilast, an anti-inflammatory drug firstly developed as an asthma treatment, is a cyclic nucleotide phosphodiesterases (PDEs) inhibitor, which mainly acts by increasing the amount of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), while downregulating the pro-inflammatory factors, such as tumor necrosis factor-α (TNF-α), macrophage migration inhibitory factor (MIF) and Toll-like receptor 4 (TLR-4). The preclinical evidence shows that ibudilast may act neuroprotectively in neurodegenerative diseases, by suppressing neuroinflammation, inhibiting apoptosis, regulating the mitochondrial function and by affecting the ubiquitin-proteasome and autophagosome-lysosome pathways, as well as by attenuating oxidative stress. The clinical trials in ALS and progressive MS also show some promising results. Herein, we aim to provide an update on the emerging preclinical and clinical evidence on the therapeutic potential of ibudilast in these disorders, discuss the potential challenges and suggest the future directions.

GSK-3β-mediated regulation of Nrf2/HO-1 signaling as a new therapeutic approach in the treatment of movement disorders

Movement disorders are neurological conditions characterized by involuntary motor movements, such as dystonia, ataxia, chorea myoclonus, tremors, Huntington's disease (HD), and Parkinson's disease (PD). It is classified into two categories: hypokinetic and hyperkinetic movements. Globally, movement disorders are a major cause of death. The pathophysiological process is initiated by excessive ROS generation, mitochondrial dysfunction, neuroinflammation, and neurotransmitters imbalance that lead to motor dysfunction in PD and HD patients. Several endogenous targets including Nrf2 maintain oxidative balance in the body. Activation of Nrf2 signaling is regulated by the enzyme glycogen synthase kinase (GSK-3β). In the cytoplasm, inhibition of GSK-3β regulates cellular proliferation, homeostasis, and apoptotic process by stimulating the nuclear factor erythroid 2 (Nrf2) pathway which is involved in the elevation of the cellular antioxidant enzymes which controls the ROS generation. The activation of Nrf2 increases the expression of antioxidant response elements (ARE), such as (Hemeoxygenase-1) HO-1, which decreases excessive cellular stress, mitochondrial dysfunction, apoptosis, and neuronal degeneration, which is the major cause of motor dysfunction. The present review explores the GSK-3β-mediated neuroprotection in various movement disorders through the Nrf2/HO-1 antioxidant pathway. This review provides a link between GSK-3β and the Nrf2/HO-1 signaling pathway in the treatment of PD and HD. In addition to that it highlights various GSK-3β inhibitors and the Nrf2/HO-1 activators, which exert robust neuroprotection against motor disorders. Therefore, the present review will help in the discovery of new therapy for PD and HD patients.

Neural stem cell secretome exerts a protective effect on damaged neuron mitochondria in Parkinson's disease model

Parkinson's disease (PD) is a common neurodegenerative disease. The main pathological changes are the loss of dopaminergic neurons and the formation of Lewy bodies. There is still no effective cure for PD, and cell replacement therapy has entered a bottleneck period due to tumorigenicity and rejection. Therefore, stem cell secretome has received widespread attention. However, the exploration of the secretome components of neural stem cells (NSCs) is still in its infancy. In this study, 6-hydroxydopamine (6-OHDA) was used to establish a PD rat model in vito and the PC12 cell-damaged model in vitro. The results indicated that the injection of neural stem cell-conditioned medium (NSC-CM) into the striatum and substantia nigra could improve the motor and non-motor deficits of PD rats and rescue the loss of dopaminergic neurons. In addition, NSC-CM alleviated 6-OHDA-induced apoptosis of PC12 cells, reduced the level of oxidative stress, and improved mitochondrial dysfunction in vitro. Parkinson disease protein 7 (Park7) was found in NSC-CM by Liquid chromatography-tandem mass spectrometry (LC-MS/MS), and it may be related to the protective effect of NSC-CM on 6-OHDA-injured neurons through Sirt1 pathway. In conclusion, NSC secretome might provide new ideas for the treatment of PD.

Transcriptome and Proteome Analysis in LUHMES Cells Overexpressing Alpha-Synuclein

LUHMES cells share many characteristics with human dopaminergic neurons in the substantia nigra, the cells, the demise of which is responsible for the motor symptoms in Parkinson's disease (PD). LUHMES cells can, therefore, be used bona fide as a model to study pathophysiological processes involved in PD. Previously, we showed that LUHMES cells degenerate after 6 days upon overexpression of wild-type alpha-synuclein. In the present study, we performed a transcriptome and proteome expression analysis in alpha-synuclein-overexpressing cells and GFP-expressing control cells in order to identify genes and proteins that are differentially regulated upon overexpression of alpha-synuclein. The analysis was performed 4 days after the initiation of alpha-synuclein or GFP overexpression, before the cells died, in order to identify processes that preceded cell death. After adjustments for multiple testing, we found 765 genes being differentially regulated (439 upregulated, 326 downregulated) and 122 proteins being differentially expressed (75 upregulated, 47 downregulated). In total, 21 genes and corresponding proteins were significantly differentially regulated in the same direction in both datasets, of these 13 were upregulated and 8 were downregulated. In total, 13 genes and 9 proteins were differentially regulated in our cell model, which had been previously associated with PD in recent genome-wide association studies (GWAS). In the gene ontology (GO) analysis of all upregulated genes, the top terms were “regulation of cell death,” “positive regulation of programmed cell death,” and “regulation of apoptotic signaling pathway,” showing a regulation of cell death-associated genes and proteins already 2 days before the cells started to die. In the GO analysis of the regulated proteins, among the strongest enriched GO terms were “vesicle,” “synapse,” and “lysosome.” In total, 33 differentially regulated proteins were associated with synapses, and 12 differentially regulated proteins were associated with the “lysosome”, suggesting that these intracellular mechanisms, which had been previously associated with PD, also play an important role in our cell model.

Therapeutic Implications of Caffeic Acid in Cancer and Neurological Diseases

Caffeic acid (CA) is found abundantly in fruits, vegetables, tea, coffee, oils, and more. CA and its derivatives have been used for many centuries due to their natural healing and medicinal properties. CA possesses various biological and pharmacological activities, including antioxidant, anti-inflammatory, anticancer, and neuroprotective effects. The potential therapeutic effects of CA are mediated via repression and inhibition of transcription and growth factors. CA possesses potential anticancer and neuroprotective effects in human cell cultures and animal models. However, the biomolecular interactions and pathways of CA have been described highlighting the target binding proteins and signaling molecules. The current review focuses on CA's chemical, physical, and pharmacological properties, including antioxidant, anti-inflammatory, anticancer, and neuroprotective effects. We further described CA's characteristics and therapeutic potential and its future directions.

Antioxidative role of Traditional Chinese Medicine in Parkinson's disease

ETHNOPHARMACOLOGICAL RELEVANCE

Neuroprotective Traditional Chinese Medicine (TCM) has been practiced in alternative medicine from early days. TCM-derived neuroprotective compounds, such as Chrysin, Cannabidiol, Toonasinoids, and β-asaron, exert significant effectiveness's towards Parkinson's disease (PD). Further, these neuroprotective TCM showed antioxidative, anti-inflammatory, anti-tumor, anti-septic, analgesic properties. Recent research showed that the reduction in the reactive oxygen species (ROS) decreased the α-synuclein (α-syn) toxicity and enhanced the dopaminergic neuron regenerations, the main hallmarks of PD. Therefore, the neuroprotective effects of novel TCM due to its antiradical activities needed deep investigations.

AIMS OF THE STUDY

This review aims to enlighten the neuroprotective TCM and its components with their antioxidative properties to the scientific community for future research.

METHOD

The relevant information on the neuroprotective TCM was gathered from scientific databases (PubMed, Web of Science, Google Scholar, ScienceDirect, SciFinder, Wiley Online Library, ACS Publications, and CNKI). Information was also gained from MS and Ph.D. thesis, books, and online databases. The literature cited in this review dates from 2001 to June 2, 0201.

RESULTS

Novel therapies for PD are accessible, mostly rely on Rivastigmine and Donepezil, offers to slow down the progression of disease at an early stage but embraces lots of disadvantages. Researchers are trying to find a potential drug against PD, which is proficient at preventing or curing the disease progress, but still needed to be further identified. Oxidative insult and mitochondrial dysfunction are thought to be the main culprit of neurodegenerations. Reactive oxygen species (ROS) are the only causative agent in all interactions, leading to PD, from mitochondrial dysfunctions, α-syn aggregative toxicity, and DA neurons degenerations. It is evident from the redox balance, which seems an imperative therapeutic approach against PD and was necessary for the significant neuronal activities.

CONCLUSION

Our study is explaining the newly discovered TCM and their neuroprotective and antioxidative properties. But also bring up the possible treatment approaches against PD for future researchers.

Challenges in Discovering Drugs That Target the Protein-Protein Interactions of Disordered Proteins

Protein–protein interactions (PPIs) outnumber proteins and are crucial to many fundamental processes; in consequence, PPIs are associated with several pathological conditions including neurodegeneration and modulating them by drugs constitutes a potentially major class of therapy. Classically, however, the discovery of small molecules for use as drugs entails targeting individual proteins rather than targeting PPIs. This is largely because discovering small molecules to modulate PPIs has been seen as extremely challenging. Here, we review the difficulties and limitations of strategies to discover drugs that target PPIs directly or indirectly, taking as examples the disordered proteins involved in neurodegenerative diseases.

Prion Protein: The Molecule of Many Forms and Faces

Cellular prion protein (PrP^C) is a glycosylphosphatidylinositol (GPI)-anchored protein most abundantly found in the outer membrane of neurons. Due to structural characteristics (a flexible tail and structured core), PrP^C interacts with a wide range of partners. Although PrP^C has been proposed to be involved in many physiological functions, only peripheral nerve myelination homeostasis has been confirmed as a bona fide function thus far. PrP^C misfolding causes prion diseases and PrP^C has been shown to mediate β-rich oligomer-induced neurotoxicity in Alzheimer’s and Parkinson’s disease as well as neuroprotection in ischemia. Upon proteolytic cleavage, PrP^C is transformed into released and attached forms of PrP that can, depending on the contained structural characteristics of PrP^C, display protective or toxic properties. In this review, we will outline prion protein and prion protein fragment properties as well as overview their involvement with interacting partners and signal pathways in myelination, neuroprotection and neurodegenerative diseases.

Differential Phospho-Signatures in Blood Cells Identify LRRK2 G2019S Carriers in Parkinson's Disease

Background

The clinicopathological phenotype of G2019S LRRK2‐associated Parkinson's disease (L2PD) is similar to idiopathic Parkinson's disease (iPD), and G2019S LRRK2 nonmanifesting carriers (L2NMCs) are at increased risk for development of PD. With various therapeutic strategies in the clinical and preclinical pipeline, there is an urgent need to identify biomarkers that can aid early diagnosis and patient enrichment for ongoing and future LRRK2‐targeted trials.

Objective

The objective of this work was to investigate differential protein and phospho‐protein changes related to G2019S mutant LRRK2 in peripheral blood mononuclear cells from G2019S L2PD patients and G2019S L2NMCs, identify specific phospho‐protein changes associated with the G2019S mutation and with disease status, and compare findings with patients with iPD.

Methods

We performed an unbiased phospho‐proteomic study by isobaric label–based mass spectrometry using peripheral blood mononuclear cell group pools from a LRRK2 cohort from Spain encompassing patients with G2019S L2PD (n = 20), G2019S L2NMCs (n = 20), healthy control subjects (n = 30), patients with iPD (n = 15), patients with R1441G L2PD (n = 5), and R1441G L2NMCs (n = 3) (total N = 93).

Results

Comparing G2019S carriers with healthy controls, we identified phospho‐protein changes associated with the G2019S mutation. Moreover, we uncovered a specific G2019S phospho‐signature that changes with disease status and can discriminate patients with G2019S L2PD, G2019S L2NMCs, and healthy controls. Although patients with iPD showed a differential phospho‐proteomic profile, biological enrichment analyses revealed similar changes in deregulated pathways across the three groups.

Conclusions

We found a differential phospho‐signature associated with LRRK2 G2019S for which, consistent with disease status, the phospho‐profile from PD at‐risk G2019S L2NMCs was more similar to healthy controls than patients with G2019S L2PD with the manifested disease. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Role of Fyn Kinase Inhibitors in Switching Neuroinflammatory Pathways

Fyn kinase is a member of the Src non-receptor tyrosine kinase family. Fyn is involved in multiple signaling pathways extending from cell proliferation and differentiation to cell adhesion and cell motility, and it has been found to be overexpressed in various types of cancers. In the central nervous system, Fyn exerts several different functions such as axon-glial signal transduction, oligodendrocyte maturation and myelination, and it is implicated in neuroinflammatory processes. Based on these premises, Fyn emerges as an attractive target in cancer and neurodegenerative disease therapy, particularly Alzheimer disease (AD), based on its activation by Aβ via cellular prion protein and its interaction with tau protein. However, Fyn is also a challenging target since the Fyn inhibitors discovered so far, due to the relevant homology of Fyn with other kinases, suffer from off-target effects. This review covers the efforts performed in the last decade to identify and optimize small molecules that effectively inhibit Fyn, both in enzymatic and in cell assays, including drug repositioning practices, as an opportunity of therapeutic intervention in neurodegeneration.

Microarray Genotyping Identifies New Loci Associated with Dementia in Parkinson's Disease

Dementia is one of the most disabling nonmotor symptoms of Parkinson’s disease (PD). However, the risk factors contributing to its development remain unclear. To investigate genetic variants associated with dementia in PD, we performed microarray genotyping based on a customized platform utilizing variants identified in previous genetic studies. Microarray genotyping was performed in 313 PD patients with dementia, 321 PD patients without dementia, and 635 healthy controls. The primary analysis was performed using a multiple logistic regression model adjusted for age and sex. SNCA single nucleotide polymorphism (SNP) rs11931074 was determined to be most significantly associated with PD (odds ratio = 0.66, 95% confidence interval = 0.56–0.78, p = 7.75 × 10⁻⁷). In the analysis performed for patients with PD only, MUL1 SNP rs3738128 (odds ratio = 2.52, 95% confidence interval = 1.68–3.79, p = 8.75 × 10⁻⁶) was found to be most significantly associated with dementia in PD. SNPs in ZHX2 and ERP29 were also associated with dementia in PD. This microarray genomic study identified new loci of MUL1 associated with dementia in PD, suggesting an essential role of mitochondrial dysfunction in the development of dementia in patients with PD.

The Non-receptor Tyrosine Kinase Pyk2 in Brain Function and Neurological and Psychiatric Diseases

Pyk2 is a non-receptor tyrosine kinase highly enriched in forebrain neurons. Pyk2 is closely related to focal adhesion kinase (FAK), which plays an important role in sensing cell contacts with extracellular matrix and other extracellular signals controlling adhesion and survival. Pyk2 shares some of FAK’s characteristics including recruitment of Src-family kinases after autophosphorylation, scaffolding by interacting with multiple partners, and activation of downstream signaling pathways. Pyk2, however, has the unique property to respond to increases in intracellular free Ca²⁺, which triggers its autophosphorylation following stimulation of various receptors including glutamate NMDA receptors. Pyk2 is dephosphorylated by the striatal-enriched phosphatase (STEP) that is highly expressed in the same neuronal populations. Pyk2 localization in neurons is dynamic, and altered following stimulation, with post-synaptic and nuclear enrichment. As a signaling protein Pyk2 is involved in multiple pathways resulting in sometimes opposing functions depending on experimental models. Thus Pyk2 has a dual role on neurites and dendritic spines. With Src family kinases Pyk2 participates in postsynaptic regulations including of NMDA receptors and is necessary for specific types of synaptic plasticity and spatial memory tasks. The diverse functions of Pyk2 are also illustrated by its role in pathology. Pyk2 is activated following epileptic seizures or ischemia-reperfusion and may contribute to the consequences of these insults whereas Pyk2 deficit may contribute to the hippocampal phenotype of Huntington’s disease. Pyk2 gene, PTK2B, is associated with the risk for late-onset Alzheimer’s disease. Studies of underlying mechanisms indicate a complex contribution with involvement in amyloid toxicity and tauopathy, combined with possible functional deficits in neurons and contribution in microglia. A role of Pyk2 has also been proposed in stress-induced depression and cocaine addiction. Pyk2 is also important for the mobility of astrocytes and glioblastoma cells. The implication of Pyk2 in various pathological conditions supports its potential interest for therapeutic interventions. This is possible through molecules inhibiting its activity or increasing it through inhibition of STEP or other means, depending on a precise evaluation of the balance between positive and negative consequences of Pyk2 actions.

GSK-3β, FYN, and DYRK1A: Master Regulators in Neurodegenerative Pathways

Protein kinases (PKs) have been recognized as central nervous system (CNS)-disease-relevant targets due to their master regulatory role in different signal transduction cascades in the neuroscience space. Among them, GSK-3β, FYN, and DYRK1A play a crucial role in the neurodegeneration context, and the deregulation of all three PKs has been linked to different CNS disorders with unmet medical needs, including Alzheimer's disease (AD), Parkinson's disease (PD), frontotemporal lobar degeneration (FTLD), and several neuromuscular disorders. The multifactorial nature of these diseases, along with the failure of many advanced CNS clinical trials, and the lengthy approval process of a novel CNS drug have strongly limited the CNS drug discovery. However, in the near-decade from 2010 to 2020, several computer-assisted drug design strategies have been combined with synthetic efforts to develop potent and selective GSK-3β, FYN, and DYRK1A inhibitors as disease-modifying agents. In this review, we described both structural and functional aspects of GSK-3β, FYN, and DYRK1A and their involvement and crosstalk in different CNS pathological signaling pathways. Moreover, we outlined attractive medicinal chemistry approaches including multi-target drug design strategies applied to overcome some limitations of known PKs inhibitors and discover improved modulators with suitable blood-brain barrier (BBB) permeability and drug-like properties.

Fyn knockdown prevents levodopa-induced dyskinesia in a mouse model of Parkinson's disease

Dopamine replacement by levodopa is the most widely used therapy for Parkinson's disease (PD), however patients often develop side effects, known as levodopa-induced dyskinesia (LID), that usually need therapeutic intervention. There are no suitable therapeutic options for LID, except for the use of the NMDA receptor antagonist amantadine, which has limited efficacy. The NMDA receptor is indeed the most plausible target to manage LID in PD and recently the kinase Fyn- one of its key regulators- became a new putative molecular target involved in LID. The aim of this work was to reduce Fyn expression to alleviate LID in a mouse model of PD. We performed intra-striatal delivery of a designed micro-RNA against Fyn (miRNA-Fyn) in 6-OHDA-lesioned mice treated with levodopa. The miRNA-Fyn was delivered either before or after levodopa exposure to assess its ability to prevent or revert dyskinesia. Pre-administration of miRNA-Fyn reduced LID with a concomitant reduction of FosB-ΔFosB protein levels -a marker of LID- as well as decreased phosphorylation of the NR2B-NMDA subunit, which is a main target of Fyn. On the other hand, post L-DOPA delivery of miRNA-Fyn was less effective to revert already established dyskinesia, suggesting that early blocking of Fyn activity might be a more efficient therapeutic approach. Together, our results provide proof of concept about Fyn as a plausible therapeutic target to manage LID, and validate RNA silencing as a potential approach to locally reduce striatal Fyn, rising new perspectives for RNA therapy interventions in PD.Significance StatementLevodopa induced dyskinesia (LID) is an incapacitant side effect of treatment in Parkinson's disease (PD). LID is a therapeutic challenge, lacking an effective pharmacological treatment, except for the use of inhibitors of the NMDA receptor, which have limited efficacy and may trigger untoward side effects. The kinase Fyn is a key regulator of NMDA function and a potential therapeutic target to control LID. Here, we show that RNA interference therapy to reduce the amount of Fyn mRNA in the adult brain is effective to prevent LID in a mouse model of PD, setting the grounds for future biomedical interventions to manage LID in PD.