The potential role of neuroinflammation and transcription factors in Parkinson disease

Screening of Parkinson's Differential MicroRNA Based on GEO Database and Its Clinical Verification

Objective

This study is set out to explore the potential difference of miR in PD through GEO data and provide diagnostic indicators for clinical practice.

Methods

In this study, differential miR was screened through the Gene Expression Omnibus (GEO) database, 68 PD patients treated in our hospital from May 2017 to March 2018 were collected as the research group (RG), and 50 normal subjects who underwent physical examination in our hospital during the same period were collected as the control group (CG). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression and diagnostic value of miR-374a-5p in serum of patients. The potential target genes of miR-374a-5p were predicted, and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and Gene Ontology Consortium (GO) were carried out.

Results

GEO2R analysis revealed that 193 miRs are expressed differentially, of which 78 were highly expressed and 115 were poorly expressed. The miR-374a-5p expression in the serum of the RG was reduced markedly and had a diagnostic value. Targetscan and miRDB online websites were used to predict their target genes, with 415 common target genes. miR-374a-5p may participate in 27 functional pathways and 8 signal pathways.

Conclusion

miR-335-5p has low expression in PD and is expected to be a potential diagnostic indicator.

Expression Analysis of NF-κB-Related lncRNAs in Parkinson's Disease

Parkinson’s disease (PD) has been shown to affect approximately 1% of the persons aged more than 65 years. This multifactorial disorder has been associated with abnormal function of NF-κB signals. In this research, we have evaluated expressions of NF-κB-related long non-coding RNAs in the circulation of PD patients compared with healthy controls. Expression of PACER was lower in total PD patients compared with healthy persons (Ratio of mean expressions (RME)=0.32, P value<0.001). This pattern was also evident among males (RME=0.25, P value<0.001). Expression of DILC was higher in total PD patients (RME=4.07, P value<0.001), and in both sex-based subgroups (RME=3.77, P value=0.01 and RME=4.25, P value<0.001, for females and males, respectively). Similarly, CEBPA was significantly over-expressed in total PD patients (RME=14.76, P value<0.001), and in both sex-based subgroups (RME=12.42, P value<0.001 and RME=15.80, P value<0.001, for females and males, respectively). ATG5 had a similar expression pattern (RME=2.6, P value=1E-08, RME=1.73, P value=0.03 and RME=3.09, P value=1E-07, for total cases, females and males, respectively). H19 was up-regulated in total cases and male cases compared with corresponding controls (RME=2.19, P value<0.001, RME=2.68, P value=0.01, respectively). Finally, HNFA1-AS was down-regulated in all comparisons (RME=0.10, P value=2E-06, RME=0.08, P value<0.001 and RME=0.12, P value<0.001, for total cases, females and males, respectively). Among PD patients, expressions of NKILA and ADINR were robustly correlated with each other (r=0.75, P value=2.40E-10). In addition, expression levels of DICER1-AS were significantly correlated with those of ADINR, PACER and H19 in these patients (r=0.73, P value=1.76E-9; r=0.72, P value=5.15E-09 and r=0.72, P value=3.09E-09, respectively). Correlation analyses among healthy controls revealed robust correlations between CHAST and CEBPA (r=0.84, P value=3.09E-09), NKILA and ADINR (r=0.80, P value=4.24E-12) as well as between DILC and CHAST (r=0.76, P value=1.70E-10). CEBPA had the best parameters among all assessed genes (AUC=0.96, Sensitivity=0.90 and specificity=0.97). DILC and ATG5 were the most appropriate markers after CEBPA with AUC values of 0.82 and 0.80, respectively. Most notably, combination of all genes improved AUC, sensitivity and specificity parameters to 1, 0.97 and 0.99, respectively. Cumulatively, the current study provides evidence for participation of NF-κB-related lncRNAs in the pathoetiology of PD.

Mitochondrial dysfunction-induced H3K27 hyperacetylation perturbs enhancers in Parkinson's disease

Mitochondrial dysfunction is a major pathophysiological contributor to the progression of Parkinson’s disease (PD); however, whether it contributes to epigenetic dysregulation remains unknown. Here, we show that both chemically and genetically driven mitochondrial dysfunctions share a common mechanism of epigenetic dysregulation. Under both scenarios, lysine 27 acetylation of likely variant H3.3 (H3.3K27ac) increased in dopaminergic neuronal models of PD, thereby opening that region to active enhancer activity via H3K27ac. These vulnerable epigenomic loci represent potential transcription factor motifs for PD pathogenesis. We further confirmed that mitochondrial dysfunction induces H3K27ac in ex vivo and in vivo (MitoPark) neurodegenerative models of PD. Notably, the significantly increased H3K27ac in postmortem PD brains highlights the clinical relevance to the human PD population. Our results reveal an exciting mitochondrial dysfunction-metabolism-H3K27ac-transcriptome axis for PD pathogenesis. Collectively, the mechanistic insights link mitochondrial dysfunction to epigenetic dysregulation in dopaminergic degeneration and offer potential new epigenetic intervention strategies for PD.

Evaluation of serum galectin-3 levels at Alzheimer patients by stages: a preliminary report

BACKGROUND AND AIMS

Neuroinflammation has a critic role in the pathophysiology of neurological diseases. The activation of microglia is the main actor in this process. The aim of this study to collect data on the role of microglial activation in the etiology, and the possible continuum at the stage of disease through the evaluation of serum galectin-3 levels in patients with Alzheimer's disease (AD).

METHODS

This was a prospective and cross-sectional study conducted on patients who were diagnosed as having AD using the criteria of the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) and stages determined with the scales of Clinical Dementia Rating (CDR) and Mini-Mental State Examination (MMSE) with healthy controls.

RESULTS

In our study, we studied 118 people, 57 with AD and 61 healthy people as a control group. In the AD patient group, serum galectin-3 levels were higher compared with the control group (p = 0.003). There were no significant differences in either group in other collected parameters (p > 0.05). It was observed that in all patients with AD, parallel to the stage of the disease, serum galectin-3 levels, patience's age, and duration of disease were statically and significantly increased (p < 0.05).

CONCLUSION

In conclusion, serum galactin-3 levels may be associated with AD and maybe a potential biomarker for the identification of disease in the early stages. In future years, serum galectin-3 levels may become an important biomarker and therapeutic agent for chronic neurodegenerative diseases such as AD.

Baicalein Exerts Anti-Neuroinflammatory Effects by Inhibiting the TLR4-ROS /NF-κB-NLRP3 Inflammasome

Emerging evidence indicates that NOD-like receptor protein 3 (NLRP3) inflammasome-induced inflammation plays a critical role in the pathogenesis of Parkinson’s disease (PD). Baicalein has been considered as a possible option for PD treatment based on its anti-neuroinflammatory effects. However, no studies have elucidated the precise mechanisms underlying the anti-neuroinflammatory activity of baicalein, particularly inflammasome-mediated effects. In this present study, rotenone-induced PD mice and BV2 microglia were used to investigate the anti-neuroinflammatory effects of baicalein and explore its underlying mechanism in vivo and in vitro. The results demonstrated that baicalein alleviated motor impairments and attenuated several inflammatory responses in rotenone-induced PD mice. Also, baicalein inhibited the expression of NLRP3 and activated caspase-1 in brain tissues. Correspondingly, baicalein prominently suppressed the inflammatory response in BV2 microglia induced by rotenone. Furthermore, in vitro data showed that baicalein suppressed the expression of NLRP3 and activated caspase-1 by abrogating the upregulation of ROS, as well as by inhibiting the TLR4/NF-κB signaling cascade. Overall, the results of the present study indicated that baicalein exerted anti-neuroinflammatory effects partly by inhibiting activation of the NLRP3 inflammasome, and targeting NLRP3 inflammasome signaling offers a novel therapeutic strategy for PD treatment.

Targeting β-Arrestins in the Treatment of Psychiatric and Neurological Disorders

Therapies for psychiatric and neurological disorders have been in the development and refinement process for the past 5 decades. Yet, most of these therapies lack optimal therapeutic efficacy and have multiple debilitating side effects. Recent advances in understanding the pathophysiological processes of psychiatric and neurological disorders have revealed an important role for β-arrestins, which are important regulators of G-protein-coupled receptor (GPCR) function, including desensitization and intracellular signaling. These findings have pushed β-arrestins to the forefront as potential therapeutic targets. Here, we highlight current knowledge on β-arrestin functions in certain psychiatric and neurological disorders (schizophrenia, Parkinson's disease, and substance abuse disorders), and how this has been leveraged to develop new therapeutic strategies. Furthermore, we discuss the obstacles impacting the field of β-arrestin-based therapeutic development and future approaches that might help advance strategies to develop optimal β-arrestin-based therapies.

Glutaminase in microglia: A novel regulator of neuroinflammation

Neuroinflammation is the inflammatory responses that are involved in the pathogenesis of most neurological disorders. Glutaminase (GLS) is the enzyme that catalyzes the hydrolysis of glutamine to produce glutamate. Besides its well-known role in cellular metabolism and excitatory neurotransmission, GLS has recently been increasingly noticed to be up-regulated in activated microglia under pathological conditions. Furthermore, GLS overexpression induces microglial activation, extracellular vesicle secretion, and neuroinflammatory microenvironment formation, which, are compromised by GLS inhibitors in vitro and in vivo. These results indicate that GLS has more complicated implications in brain disease etiology than what are previously known. In this review, we introduce GLS isoforms, expression patterns in the body and the brain, and expression/activities regulation. Next, we discuss the metabolic and neurotransmission functions of GLS. Afterwards, we summarize recent findings of GLS-mediated microglial activation and pro-inflammatory extracellular vesicle secretion, which, in turns, induces neuroinflammation. Lastly, we provide a comprehensive discussion for the involvement of microglial GLS in the pathogenesis of various neurological disorders, indicating microglial GLS as a promising target to treat these diseases.

Recent developments on PET radiotracers for TSPO and their applications in neuroimaging

The 18 kDa translocator protein (TSPO), previously known as the peripheral benzodiazepine receptor, is predominately localized to the outer mitochondrial membrane in steroidogenic cells. Brain TSPO expression is relatively low under physiological conditions, but is upregulated in response to glial cell activation. As the primary index of neuroinflammation, TSPO is implicated in the pathogenesis and progression of numerous neuropsychiatric disorders and neurodegenerative diseases, including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), multiple sclerosis (MS), major depressive disorder (MDD) and obsessive compulsive disorder (OCD). In this context, numerous TSPO-targeted positron emission tomography (PET) tracers have been developed. Among them, several radioligands have advanced to clinical research studies. In this review, we will overview the recent development of TSPO PET tracers, focusing on the radioligand design, radioisotope labeling, pharmacokinetics, and PET imaging evaluation. Additionally, we will consider current limitations, as well as translational potential for future application of TSPO radiopharmaceuticals. This review aims to not only present the challenges in current TSPO PET imaging, but to also provide a new perspective on TSPO targeted PET tracer discovery efforts. Addressing these challenges will facilitate the translation of TSPO in clinical studies of neuroinflammation associated with central nervous system diseases.

Subthalamic nucleus deep brain stimulation suppresses neuroinflammation by Fractalkine pathway in Parkinson's disease rat model

Subthalamic nucleus deep brain stimulation (STN-DBS) is widely used to treat patients with Parkinson's disease (PD), and recent studies have shown that it is more beneficial for early stages, suggesting a potential neuroprotective effect. And the neuroinflammation plays an indispensable role in progress of PD. However, the underlying mechanisms are not well understood. The aim of this study was to investigate the effect of STN-DBS on neuroinflammation and the potential pathway. To address this question, we established a rat PD model by unilateral 6-hydroxydopamine injection into the left striatum and implanted stimulation leads into the ipsilateral STN to deliver electrical stimulation for a week. The neuroprotective effects of STN-DBS were examined by molecular biology techniques, including western blotting, immunohistochemistry and so on. We found that motor deficits were alleviated by STN-DBS, with increased survival of dopaminergic neurons in the substantia nigra (SN). Furthermore, STN-DBS decreased Fractalkine (CX3CL1) and its receptor (CX3CR1) expression. Meanwhile, the suppressed microglia activation and nuclear factor-κB expression, decrease in the levels of pro-inflammatory cytokine interleukin (IL)-1β and IL-6 and increase in anti-inflammatory cytokine IL-4, downregulated IL-1 receptor, extracellular signal-regulated kinase (ERK) and cleaved-caspase3 were also observed in SN of PD models received STN-DBS. In conclusion, we observed a significant association between the suppressed neuroinflammation and STN-DBS, which may be attributed to CX3CL1/CX3CR1 signaling. These results provide novel insight into the mechanistic basis of STN-DBS therapy for PD.

The role of pharmacogenomics in the personalization of Parkinson's disease treatment

Parkinson's disease (PD)-related phenotypes can vary among patients substantially, including response to dopaminergic treatment in terms of efficacy and occurrence of adverse events. Many pharmacogenetic studies have already been conducted to find genetic markers of response to dopaminergic treatment. Integration of genetic and clinical data has already resulted in construction of clinical pharmacogenetic models for prediction of adverse events. However, the results of pharmacogenetic studies are inconsistent. More comprehensive genome-wide approaches are needed to find genetic biomarkers of PD-related phenotypes to better explain the variability in response to treatment. These genetic markers should be integrated with clinical, environmental, imaging, and other omics data to build clinically useful algorithms for personalization of PD management.

Astrocyte-specific deletion of the transcription factor Yin Yang 1 in murine substantia nigra mitigates manganese-induced dopaminergic neurotoxicity

Manganese (Mn)-induced neurotoxicity resembles Parkinson's disease (PD), but the mechanisms underpinning its effects remain unknown. Mn dysregulates astrocytic glutamate transporters, GLT-1 and GLAST, and dopaminergic function, including tyrosine hydroxylase (TH). Our previous in vitro studies have shown that Mn repressed GLAST and GLT-1 via activation of transcription factor Yin Yang 1 (YY1). Here, we investigated if in vivo astrocytic YY1 deletion mitigates Mn-induced dopaminergic neurotoxicity, attenuating Mn-induced reduction in GLAST/GLT-1 expression in murine substantia nigra (SN). AAV5-GFAP-Cre-GFP particles were infused into the SN of 8-week-old YY1 ^flox/flox mice to generate a region-specific astrocytic YY1 conditional knockout (cKO) mouse model. 3 weeks after adeno-associated viral (AAV) infusion, mice were exposed to 330 μg of Mn (MnCl₂ 30 mg/kg, intranasal instillation, daily) for 3 weeks. After Mn exposure, motor functions were determined in open-field and rotarod tests, followed by Western blotting, quantitative PCR, and immunohistochemistry to assess YY1, TH, GLAST, and GLT-1 levels. Infusion of AAV5-GFAP-Cre-GFP vectors into the SN resulted in region-specific astrocytic YY1 deletion and attenuation of Mn-induced impairment of motor functions, reduction of TH-expressing cells in SN, and TH mRNA/protein levels in midbrain/striatum. Astrocytic YY1 deletion also attenuated the Mn-induced decrease in GLAST/GLT-1 mRNA/protein levels in midbrain. Moreover, YY1 deletion abrogated its interaction with histone deacetylases in astrocytes. These results indicate that astrocytic YY1 plays a critical role in Mn-induced neurotoxicity in vivo, at least in part, by reducing astrocytic GLAST/GLT-1. Thus, YY1 might be a potential target for treatment of Mn toxicity and other neurological disorders associated with dysregulation of GLAST/GLT-1.

Neuroprotective Properties of Green Tea (Camellia sinensis) in Parkinson's Disease: A Review

Neurodegenerative disease is a collective term given for the clinical condition, which results in progressive degeneration of neurons and the loss of functions associated with the affected brain region. Apart from the increase in age, neurodegenerative diseases are also partly affected by diet and lifestyle practices. Parkinson's disease (PD) is a slow onset neurodegenerative disorder and the second most common neurodegenerative disease, which affects the motor system. Although there is no prescribed treatment method to prevent and cure PD, clinical procedures help manage the disease symptoms. Green tea polyphenols are known for several health benefits, including antioxidant, anti-inflammatory, and neuroprotective activity. The current manuscript summarizes the possible mechanisms of neuroprotective potential of green tea with a special focus on PD. Studies have suggested that the consumption of green tea protects against free-radicals, inflammation, and neuro-damages. Several in vivo studies aid in understanding the overall mechanism of green tea. However, the same dose may not be sufficient in humans to elicit similar effects due to complex physiological, social, and cultural development. Future research focused on more clinical trials could identify an optimum dose that could impart maximum health benefits to impart neuroprotection in PD.

Updates on Versatile Role of Putative Gasotransmitter Nitric Oxide: Culprit in Neurodegenerative Disease Pathology

Nitric oxide (NO) is a versatile gasotransmitter that contributes in a range of physiological and pathological mechanims depending on its cellular levels. An appropriate concentration of NO is essentially required for cellular physiology; however, its increased level triggers pathological mechanisms like altered cellular redox regulation, functional impairment of mitochondrion, and modifications in cellular proteins and DNA. Its increased levels also exhibit post-translational modifications in protein through S-nitrosylation of their thiol amino acids, which critically affect the cellular physiology. Along with such modifications, NO could also nitrosylate the endoplasmic reticulum (ER)-membrane located sensors of ER stress, which subsequently affect the cellular protein degradation capacity and lead to aggregation of misfolded/unfolded proteins. Since protein aggregation is one of the pathological hallmarks of neurodegenerative disease, NO should be taken into account during development of disease therapies. In this Review, we shed light on the diverse role of NO in both cellular physiology and pathology and discussed its involvement in various pathological events in the context of neurodegenerative diseases.

Nanomaterial based drug delivery systems for the treatment of neurodegenerative diseases

With an aging population that has been increasing in recent years, the need for the development of therapeutic approaches for treatment of neurodegenerative disorders (ND) has increased. ND, which are characterized by the progressive loss of the structure or function of neurons, are often associated with neuronal death. In spite of screening numerous drugs, currently there is no specific treatment that can cure these diseases or slow down their progression. Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), frontotemporal dementia, Huntington's disease, and prion diseases belong to ND which affect enormous numbers of people globally. There are some main possible reasons for failure in the treatment of neurodegenerative diseases such as limitations introduced by the Blood-Brain Barrier (BBB), the Blood-Cerebrospinal Fluid Barrier (BCFB) and P-glycoproteins. Current advances in nanotechnology present opportunities to overcome the mentioned limitations by using nanotechnology and designing nanomaterials improving the delivery of active drug candidates. Some of the basic and developing strategies to overcome drug delivery impediments are the local delivery of drugs, receptor-mediated transcytosis, physicochemical disruption of the BBB, cell-penetrating peptides and magnetic disruption. Recently, the application of nanoparticles has been developed to improve the efficiency of drug delivery. Nanoengineered particles as nanodrugs possess the capacity to cross the BBB and also show decreased invasiveness. Examples include inorganic, magnetic, polymeric and carbonic nanoparticles that have been developed to improve drug delivery efficiency. Despite numerous papers published in this filed, there are some unsolved issues that need to be addressed for successful treatment of neurodegenerative diseases. These are discussed herein.

The therapeutic role of cannabinoid receptors and its agonists or antagonists in Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disease and its characteristic is the progressive degeneration of dopaminergic neurons within the substantia nigra (SN) of the midbrain. There is hardly any clinically proven efficient therapeutics for its cure in several recent preclinical advances proposed to treat PD. Recent studies have found that the endocannabinoid signaling system in particular the comprised two receptors, CB1 and CB2 receptors, has a significant regulatory function in basal ganglia and is involved in the pathogenesis of PD. Therefore, adding new insights into the biochemical interactions between cannabinoids and other signaling pathways may help develop new pharmacological strategies. Factors of the endocannabinoid system (ECS) are abundantly expressed in the neural circuits of basal ganglia, where they interact interactively with glutamatergic, γ-aminobutyric acid-ergic (GABAergic), and dopaminergic signaling systems. Although preclinical studies on PD are promising, the use of cannabinoids at the clinical level has not been thoroughly studied. In this review, we evaluated the available evidence and reviewed the involvement of ECS in etiologies, symptoms and treatments related to PD. Since CB1 and CB2 receptors are the two main receptors of endocannabinoids, we primarily put the focus on the therapeutic role of CB1 and CB2 receptors in PD. We will try to determine future research clues that will help understand the potential therapeutic benefits of the ECS in the treatment of PD, aiming to open up new strategies and ideas for the treatment of PD.

Baicalein attenuates the neuroinflammation in LPS-activated BV-2 microglial cells through suppression of pro-inflammatory cytokines, COX2/NF-κB expressions and regulation of metabolic abnormality

Baicalein (5,6,7-trihydroxyflavone), isolated from the root of traditional Chinese herb Scutellaria baicalensis Georgi, has anti-inflammatory and anti-oxidative activities. This study explored the protective and modulatory mechanisms of baicalein on neuroinflammation, oxidative stress and metabolic abnormality in lipopolysaccharide (LPS)-activated BV-2 cells. Our results demonstrated that treatment with baicalein remarkably restrained the production of pro-inflammatory factors including nitric oxide (NO), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in LPS-activated BV-2 cells. Moreover, baicalein significantly inhibited reactive oxygen species (ROS) production, decreased cyclooxygenase-2 (COX-2) and nuclear factor-b (NF-κB)/p65 expression. ¹H NMR metabolomics analysis revealed that 12 differential metabolites were regulated by baicalein, implicated in alanine, aspartate and glutamate metabolism, glutathione metabolism, arginine and proline metabolism, D-glutamine and D-glutamate metabolism. In conclusion, these results indicated that baicalein has protective and modulatory effects on neuroinflammation and oxidative stress in LPS-activated BV-2 cells.

The role of astrocytic glutamate transporters GLT-1 and GLAST in neurological disorders: Potential targets for neurotherapeutics

Glutamate is the primary excitatory neurotransmitter in the central nervous system (CNS) which initiates rapid signal transmission in the synapse before its re-uptake into the surrounding glia, specifically astrocytes. The astrocytic glutamate transporters glutamate-aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1) and their human homologs excitatory amino acid transporter 1 (EAAT1) and 2 (EAAT2), respectively, are the major transporters which take up synaptic glutamate to maintain optimal extracellular glutamic levels, thus preventing accumulation in the synaptic cleft and ensuing excitotoxicity. Growing evidence has shown that excitotoxicity is associated with various neurological disorders, including amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), Parkinson's disease (PD), manganism, ischemia, schizophrenia, epilepsy, and autism. While the mechanisms of neurological disorders are not well understood, the dysregulation of GLAST/GLT-1 may play a significant role in excitotoxicity and associated neuropathogenesis. The expression and function of GLAST/GLT-1 may be dysregulated at the genetic, epigenetic, transcriptional or translational levels, leading to high levels of extracellular glutamate and excitotoxicity. Consequently, understanding the regulatory mechanisms of GLAST/GLT-1 has been an area of interest in developing therapeutics for the treatment of neurological disorders. Pharmacological agents including β-lactam antibiotics, estrogen/selective estrogen receptor modulators (SERMs), growth factors, histone deacetylase inhibitors (HDACi), and translational activators have shown significant efficacy in enhancing the expression and function of GLAST/GLT-1 and glutamate uptake both in vitro and in vivo. This comprehensive review will discuss the regulatory mechanisms of GLAST/GLT-1, their association with neurological disorders, and the pharmacological agents which mediate their expression and function. This article is part of the issue entitled 'Special Issue on Neurotransmitter Transporters'.

Downregulated lncRNA-SNHG1 enhances autophagy and prevents cell death through the miR-221/222 /p27/mTOR pathway in Parkinson's disease

Autophagy has been shown to be critically associated with the central mechanisms underlying Parkinson's disease (PD), while the mechanisms contributing to the imbalance of autophagy remain unclear. Small nucleolar RNA host gene 1 (SNHG1), a well-studied long noncoding RNA, has been reported to be significantly increased in PD. The potential biological functions of SNHG1 in the regulation of neuronal autophagy and cell death in PD, however, have not yet been completely elucidated. In this study, we examined the existence of regulatory networks involving SNHG1, the miR-221/222 cluster and the cyclin-dependent kinase inhibitor 1B (CDKN1B/p27)/mammalian target of rapamycin (mTOR) signaling pathway in PD. We observed that SNHG1 expression was gradually upregulated in PD cellular and animal models. Furthermore, silencing SNHG1 promoted autophagy and prevented MPP⁺-induced cell death, similar to the overexpression of the miR-221/222 cluster. Mechanistically, SNHG1 competitively binds to the miR-221/222 cluster and indirectly regulates the expression of p27/mTOR. In conclusion, these results demonstrated that downregulation of SNHG1 attenuated MPP⁺-induced decreases in LC3-II (an autophagic marker) levels and cytotoxicity through the miR-221/222/p27/mTOR pathway, suggesting that SNHG1 may be a therapeutic target for neuroprotection and disease treatment in PD.

Gene Regulatory Networks in Peripheral Mononuclear Cells Reveals Critical Regulatory Modules and Regulators of Multiple Sclerosis

Multiple sclerosis (MS) is a complex, demyelinating disease with the involvement of autoimmunity and neurodegeneration. Increasing efforts have been made towards identifying the diagnostic markers to differentiate the classes of MS from other similar neurological conditions. Using a systems biology approach, we constructed four types of gene regulatory networks (GRNs) involved in peripheral blood mononuclear cells (PBMCs). The regulatory strength of each GRN across primary progressive MS (PPMS), relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), and control were evaluated by an integrity algorithm. Among the constructed GRNs (referred as TF_gene_miRNA), POU3F2_CDK6_hsa-miR-590-3p, MEIS1_CASC3_hsa-miR-1261, STAT3_OGG1_hsa-miR-298, and TCF4_FMR1_hsa-miR-301b were top-ranked and differentially regulated in all classes of MS compared to control. These GRNs showed potential involvement in regulating various molecular pathways such as interleukin, integrin, glypican, sphingosine phosphate, androgen, and Wnt signaling pathways. For validation, the qPCR analysis of the GRN components (TFs, gene, and miRNAs) in PBMCs of healthy controls (n = 30), RRMS (n = 14), PPMS (n = 13) and SPMS (n = 12) were carried out. Real-time expression analysis of GRNs showed a similar regulatory pattern as derived from our systems biology approach. Also, our study provided several novel GRNs that regulate unique and common molecular mechanisms between MS conditions. Hence, these regulatory components of GRNs will help to understand the disease mechanism across MS classes and further insight may though light towards diagnosis.

A preliminary data: Evaluation of serum Galectin-3 levels in patients with Idiopathic Parkinson's Disease

AIM

In our study, we aimed to collect data for the hypothesis that Galectin-3 might be used as a new prognostic and therapeutic biomarker in Idiopathic Parkinson's Disease (IPD).

METHOD

In this prospective and cross-sectional study, the Unified Parkinson's Disease Rating Scale (UPDRS) and Modified Hoehn and Yahr (H&Y) scales were applied to each patient diagnosed as IPD according to the UK Brain Bank diagnostic criteria. The control group consisted of healthy individuals with the same age, gender, and body mass index characteristics as the patients meeting the exclusion criteria.

RESULTS

A total of 111 cases were included in the study, 48 were IPD, and 63 were healthy controls. There were no statistically significant differences between the IPD and control groups in terms of demographic, anthropometric, and blood parameters (p > 0.05). Serum galectin-3 levels were significantly higher in IPD than the control group (p < 0.001). Serum galectin-3 levels, UPDRS scores, and duration of disease were significantly higher in patients with IPD in parallel with the progression of the disease (p < 0.001; 0.001; 0.009). No significant relationship was detected between the stage of the disease and other parameters (p < 0.05).

CONCLUSION

Our study supports the hypothesis that serum galectin-3 level might be associated with IPD. Our data suggest that serum galectin-3 levels might be an accessible biomarker for the detection and prevention of chronic, progressive diseases such as IPH.

Association Between MTHFR Genetic Polymorphism and Parkinson's Disease Susceptibility: A Meta-analysis

Folate metabolism plays quite a critical role in Parkinson’s disease (PD). Previous published research works have studied the link existing between the folate metabolism genetic polymorphisms and PD susceptibility; nevertheless, the results continue having controversies and inconclusiveness. Accordingly, we carried out the present meta-analysis for the assessment of the potential link between the folate metabolism genetic polymorphisms and the susceptibility to PD. In addition we carried out a literature search in the PubMed, EMBASE, Cochrane Library, and WanFang databases till November 10, 2018. The odds ratios (ORs) with corresponding 95% credible interval (95%CI) were put to use for evaluating the strength of the association of three folate metabolism genetic polymorphism ( C677T, A1298C, and A2756G) with the susceptibility to PD. Each statistical analysis was carried out with the use of STATA 15.0. An aggregate of twenty-one case-control investigations were retrieved, which involved 3,944 PD patients and 4,412 controls. We discovered the existence of no substantial link between the C677T and A1298C polymorphism and PD risk in any genetic framework comparisons. With regard to A2756G polymorphism, we discovered that there was an association between the A2756G genetic polymorphism and an augmented threat of PD in the co-dominant genetic framework (GG vs. AA: OR=1.86, 95%CI=1.02-3.37, P=0.042) and the recessive genetic model (GG vs. GA+AA: OR=1.90, 95%CI=1.06-3.41, P=0.031). To summarize, our research work indicates that the A2756G polymorphism of the folate metabolism gene had an association with an augmented threat of PD. Also, A1298C polymorphisms is unlikely to significantly contribute towards the susceptibility to PD. Further large-scale case-control studies are still required.

NLRP3 inflammasome pathway is involved in olfactory bulb pathological alteration induced by MPTP

Olfactory bulb, as one of sensory organs opening to the outside, is susceptible to toxic environment and easy to deteriorate. Recent studies in Parkinson's disease (PD) patients and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkeys have shown that abnormal α-synuclein is accumulated in the olfactory glomeruli, suggesting that the lesions of PD are not only confined to the substantia nigra (SN) but also located in the olfactory bulb. Thus, olfactory bulb might be the region of onset in PD pathogenesis and a targeted region for diagnosis and treatment of PD. However, the relationship between olfactory bulb and pathogenesis of PD remains unclear. In the present study, we investigated the inflammatory pathological alterations in olfactory bulb and the underlying mechanisms in chronic MPTP mice. Mice were treated with MPTP/P, i.e., MPTP (25 mg/kg, s.c.) plus probenecid (250 mg/kg, i.p.) every 4 days, for ten times. The mice displayed typical parkinsonian syndrome. Then we examined their olfactory function and the pathologic changes in olfactory bulb. The mice showed obvious olfactory dysfunction in a buried pellet test. Immunohistochemical studies revealed that tyrosine hydroxylase (TH) protein levels were significantly decreased, whereas abnormal α-synuclein was significantly increased in the olfactory bulbs. Furthermore, the olfactory bulbs in MPTP/P-treated mice showed significantly increased levels of interleukin-1β (IL-1β), caspase-1, glial fibrillary acidic protein (GFAP), Toll receptor 4 (TLR4), phosphorylation of p65, as well as activated molecules of NOD-like receptor protein 3 (NLRP3) that were associated with neuroinflammation. Our results demonstrate that MPTP/P-caused olfactory bulb damage might be related to NLRP3-mediated inflammation.

Farrerol protects dopaminergic neurons in a rat model of lipopolysaccharide-induced Parkinson's disease by suppressing the activation of the AKT and NF-κB signaling pathways

Neuroinflammation, characterized by the activation of microglia, is one of the major pathologic processes of Parkinson's disease (PD). Overactivated microglia can release many pro-inflammatory cytokines, which cause an excessive inflammatory response and eventually damage dopaminergic neurons. Therefore, the inhibition of neuroinflammation that results from the overactivation of microglia may be an method for the treatment of PD. Farrerol is a 2,3-dihydro-flavonoid obtained from Rhododendron, and it possesses various biological functions, including anti-inflammatory, antibacterial and antioxidant activities. However, the effect of farrerol on neuroinflammation has not been investigated. The present study uncovered a neuroprotective role for farrerol. In vitro, farrerol markedly decreased the production of inflammatory mediators, including interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), cyclooxygenase 2 (COX-2) and induced nitric oxide synthase (iNOS), induced by lipopolysaccharide (LPS) in BV-2 cells. This anti-inflammatory effect was regulated via inhibiting NF-κB p65 and AKT phosphorylation. Furthermore, we found that farrerol alleviated microglial activation and dopaminergic neuronal death in rats with LPS-induced PD. Pretreatment with farrerol markedly improved motor deficits in rats with LPS-induced PD. Taken together, our results indicate that the neuroprotective effect of the farrerol, which prevents microglial overactivation in rats with LPS-induced PD, may provide a potential therapy for patients suffering from PD.

Hesperetin inhibits neuroinflammation on microglia by suppressing inflammatory cytokines and MAPK pathways

Neuroinflammation is a specific or nonspecific immunological reaction in the central nervous system that is induced by microglia activation. Appropriate regulation of activated microglial cells is therefore important for inhibiting neuroinflammation. Hesperetin is a natural flavanone and an aglycone of hesperidin that is found in citrus fruits. Hesperetin reportedly possesses anti-inflammatory, anti-cancer, and antioxidant effects. However, the anti-neuroinflammatory effects of hesperetin on microglia are still unknown. Here, we investigated the anti-neuroinflammatory effects of hesperetin on lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. We found that hesperetin strongly inhibited nitric oxide production and expression of inducible nitric oxide synthase in LPS-stimulated BV-2 microglial cells. Hesperetin also significantly reduced secretion of inflammatory cytokines including interleukin (IL)-1β and IL-6. Furthermore, hesperetin down-regulated the phosphorylation of extracellular signal-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinase, exerting anti-inflammatory effects. Hesperetin suppressed astrocyte and microglia activation in the LPS-challenged mouse brain. Collectively, our findings indicate that hesperetin inhibits microglia-mediated neuroinflammation and could be a prophylactic treatment for neurodegenerative diseases.

Diosgenin Attenuates Lipopolysaccharide-Induced Parkinson's Disease by Inhibiting the TLR/NF-κB Pathway

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disease characterized by loss of dopaminergic neurons in the substantia nigra. Diosgenin is a natural steroid saponin which was shown to play a beneficial role in Alzheimer's disease.

OBJECTIVE

This study sought to investigate the potential effect of diosgenin on a rat model of PD.

METHODS

Sprague Dawley rats were subjected to intra-striatal injection of lipopolysaccharide (LPS) and treated with diosgenin. Stepping, Whisker, and Cylinder tests were carried out to determine the motor function, and the expression of tyrosine hydroxylase was detected by immunohistochemistry. The levels of multiple proinflammatory cytokines, oxidative stress related factors and proteins involved in Toll-like receptor (TLR)/nuclear factor kappa B (NF-κB) pathway were measured. The synergistic effect of environment enrichment on diosgenin was also investigated.

RESULTS

Intra-striatal injection of LPS caused motor deficits in rats, induced inflammatory response and oxidative stress response, and activated the TLR/NF-κB pathway both in vivo and in vitro. Diosgenin could attenuate the LPS-induced alterations. Enriched environment enhanced the effect of diosgenin to ameliorate the LPS-induced motor deficits in rats and decreased the protein levels of TLR2, TLR4, and nuclear NF-κB in diosgenin treated PD rats.

CONCLUSION

Diosgenin had a beneficial effect in LPS-induced rat PD models, by suppressing the TLR/NF-κB signaling pathway. Environmental enrichment could play a synergistic effect with diosgenin, by enhancing the inhibitory effect of diosgenin on the TLR/ NF-κB signaling pathway.

Inflammatory process in Parkinson disease: neuroprotection by neuropeptide Y

Parkinson's disease (PD) is characterized by the degeneration of dopaminergic neurons in the nigro-striatal pathway. Interestingly, it has already been shown that an intracerebral administration of neuropeptide Y (NPY) decreases the neurodegeneration induced by 6-hydroxydopamine (6-OHDA) in rodents and prevents loss of dopamine (DA) and DA transporter density. The etiology of idiopathic PD now suggest that chronic production of inflammatory mediators by activated microglial cells mediates the majority of DA-neuronal tissue destruction. In an animal experimental model of PD, the present study shows that NPY inhibited the activation of microglia evaluated by the binding of the translocator protein (TSPO) ligand [3H]PK11195 in striatum and substantia nigra of 6-OHDA rats. These results suggest a potential role for inflammation in the pathophysiology of the disease and a potential treatment by NPY in PD.

Tremor-Dominant in Parkinson Disease: The Relevance to Iron Metabolism and Inflammation

Background: Tremor is one of the most predominant symptoms of patients with Parkinson disease (PD), but the underlying mechanisms for tremor relating to iron and its metabolism-related proteins and the inflammatory factors in cerebrospinal fluid (CSF) and serum have not been fully elucidated. Methods: A total of 135 PD patients were divided into a tremor-dominant (PD-TD) group (N = 74) and a postural instability and gait difficulty-dominant (PD-PIGD) group (N = 39) based on the ratio of mean tremor score to the mean bradykinesia/rigid score of the Unified Parkinson's Disease Rating Scale (UPDRS) III. Age and sex-matched healthy controls were recruited (N = 35). Demographic variables were evaluated; iron and its metabolism-related proteins and the inflammatory mediators in both CSF and serum were measured in these groups. The relevance of iron metabolism, inflammation and PD-TD were analyzed. Results: (1) The PD-TD group had significantly decreased L-ferritin, increased iron levels in CSF and increased ferritin levels in the serum compared with the PD-PIGD and control groups (P < 0.05). (2) The PD-TD group had significantly enhanced IL-6 levels in both CSF and serum compared with the PD-PIGD and control groups (P < 0.05). (3) In CSF, the IL-6 level was increased as the iron level was elevated in the PD-TD group (r = 0.308, P = 0.022). In serum, the IL-6 level was increased as the ferritin level was elevated in the PD-TD group (r = 0.410, P = 0.004). Conclusion: The interplay between disturbed iron metabolism and relevant inflammation might modulate clinical phenotypes of PD.

Dl-3-n-Butylphthalide Exerts Dopaminergic Neuroprotection Through Inhibition of Neuroinflammation

Microglia-mediated neuroinflammation contributes to multiple neurodegenerative disorders, including PD. Therefore, the regulation of microglial activation probably has the therapeutic potential. This study is aimed to determine whether NBP could suppress microglial activation and protect dopaminergic neurons from excessive neuroinflammation. In the present study, MPTP-induced PD model was established to explore the neuroprotective and anti-inflammatory effect of NBP. We assessed motor deficits, dopaminergic neurodegeneration and microglial activation in PD mice. In vitro, the anti-inflammatory activity of NBP was confirmed by cell viability assay of SH-SY5Y cells after being treated with conditioned medium from LPS-stimulated BV-2 cells and from 1-Methyl-4-phenylpyridinium iodide (MPP⁺)-stimulated BV-2 cells. The expression of pro-inflammatory molecules was determined by RT-PCR, Western Blot and ELISA assay. The generation of NO and ROS were also assessed. The involvement of signaling pathways such as MAPK, NF-κB, and PI3k/Akt were further investigated by Western Blot and immunofluorescence assay. The neuroprotective effect of NBP was demonstrated in vivo as shown by the improvement of dopaminergic neurodegeneration, motor deficits and microglial activation in MPTP-induced mouse model of PD. The expression of pro-inflammatory mediators was also reduced by NBP administration. In vitro, NBP also protected dopaminergic neurons from neurotoxicity induced by activated microglia. NBP pretreatment not only reduced pro-inflammatory molecules, but also suppressed NO release and ROS generation in BV-2 cells. Further mechanism research suggested that the inactivation of MAPK, NF-κB and PI3K/Akt may involve in anti-neuroinflammation role of NBP. In conclusion, our results revealed that NBP exerted dopaminergic neuroprotection through inhibition of microglia-mediated neuroinflammation, suggesting the promising therapeutic effect of NBP for PD.

Gene Dysfunction Mediates Immune Response to Dopaminergic Degeneration in Parkinson's Disease

Many publications reported that genetic dysfunction mediates abnormal immune responses in the brain, which is important for the development of neurodegenerative diseases, especially for Parkinson's disease (PD). This immune disorder results in subsequent inflammatory reaction, which stimulates microglia or other immune cells to secrete cytokines and chemokines and disturbs the proportion of peripheral blood lymphocyte subsets contributing to dopaminergic (DA) neuron apoptosis. Furthermore, the abnormal immune related signal pathways caused by genetic variants promote chronic inflammation destroying the blood-brain barrier, which allows infiltration of different molecules and blood cells into the central nervous system (CNS) exerting toxicity on DA neurons. As a result, the inflammatory reaction in the CNS accelerates the progression of Parkinson's disease and promotes α-synuclein aggregation and diffusion among DA neurons in the procession of Parkinson's disease. Thus, for disease evaluation, the genetic mediated abnormal immune response in PD may be assessed based on the multiple immune molecules and inflammatory factors, as well as the ratio of lymphocyte subsets from PD patient's peripheral blood as potential biomarkers.

Cytokine Research in Depression: Principles, Challenges, and Open Questions

Cytokines have been implicated in the pathology of depression. Currently, the evidence is based on cross-sectional studies and meta-analytic research comparing blood concentrations of T helper type 1 (TH1), T helper type 2 (TH2), pro-inflammatory or anti-inflammatory cytokines of patients with a depressive disorder to those of healthy controls. Additionally, multiple longitudinal studies have investigated cytokine levels during antidepressant treatment. According to the current literature, it seems that peripheral levels of interleukin (IL)-6, IL-10, IL-12, IL-13, and tumor necrosis factor (TNF)-α are elevated and that interferon (IFN)-γ levels are lower in patients with depression compared to healthy controls. However, the overlap of cytokine values between acutely depressed patients, remitted and recovered patients and healthy controls is considerable. Thus, the discriminative power of cytokine concentrations between depressed and non-depressed people is likely weak. Treatment with certain antidepressants appears to decrease peripheral levels of IL-6, IL-10, and TNF-α. However, weight gain-inducing psychopharmacological substances, such as the antidepressant mirtazapine, have been reported to potentially increase the production of pro-inflammatory cytokines. Even though cytokines are often discussed as biomarkers for depression, they have also been shown to be altered in other psychiatric disorders. Moreover, many environmental, social, psychological, biological, and medical factors are also associated with cytokine changes. Thus, cytokine alterations seem extremely unspecific. The interpretation of the results of these studies remains a challenge because it is unknown which type of cells are most responsible for cytokine changes measured in the blood nor have the main target cells or target tissues been identified. The same cytokine can be produced by multiple cell types, and the same cell can produce various cytokines. Additionally, redundancy, synergy, antagonism, and signaling cascades of cytokine signaling must be considered. Cytokines might not be associated with the diagnosis of depression according to the currently used diagnostic manuals, but rather with specific subtypes of depression, or with depressive symptoms across different psychiatric diagnoses. Therefore, the currently available diagnostic systems may not be the ideal starting point for psychiatric cytokine research.

NRF2 and NF-қB interplay in cerebrovascular and neurodegenerative disorders: Molecular mechanisms and possible therapeutic approaches

Electrophiles and reactive oxygen species (ROS) play a major role in modulating cellular defense mechanisms as well as physiological functions, and intracellular signaling. However, excessive ROS generation (endogenous and exogenous) can create a state of redox imbalance leading to cellular and tissue damage (Ma and He, 2012) [1]. A growing body of research data strongly suggests that imbalanced ROS and electrophile overproduction are among the major prodromal factors in the onset and progression of several cerebrovascular and neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS), stroke, Alzheimer's disease (AD), Parkinson's disease (PD), and aging (Ma and He, 2012; Ramsey et al., 2017; Salminen et al., 2012; Sandberg et al., 2014; Sarlette et al., 2008; Tanji et al., 2013) [1-6]. Cells offset oxidative stress by the action of housekeeping antioxidative enzymes (such as superoxide dismutase, catalase, glutathione peroxidase) as well direct and indirect antioxidants (Dinkova-Kostova and Talalay, 2010) [7]. The DNA sequence responsible for modulating the antioxidative and cytoprotective responses of the cells has been identified as the antioxidant response element (ARE), while the nuclear factor erythroid 2-related factor (NRF2) is the major regulator of the xenobiotic-activated receptor (XAR) responsible for activating the ARE-pathway, thus defined as the NRF2-ARE system (Ma and He, 2012) [1]. In addition, the interplay between the NRF2-ARE system and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB, a protein complex that controls cytokine production and cell survival), has been further investigated in relation to neurodegenerative and neuroinflammatory disorders. On these premises, we provide a review analysis of current understanding of the NRF2-NF-ĸB interplay, their specific role in major CNS disorders, and consequent therapeutic implication for the treatment of neurodegenerative and cerebrovascular diseases.

Gastrointestinal Dysfunctions Are Associated with IL-10 Variants in Parkinson's Disease

Inflammation has been demonstrated to be involved in Parkinson's disease (PD) pathogenesis. There were evidences that the disturbance of the protective function of IL-10 gene contributed to PD. In our study, haplotype analyses were conducted of IL-10 rs1800871 and rs1800872 on 371 PD patients. Because the two SNPs exposed significant linkage disequilibrium demonstrated by Haploview software, we included 177 carriers of both rs1800871 and rs1800872 and 190 noncarriers in clinical phenotype analyses. As to nonmotor symptoms, the score of the gastrointestinal dysfunction domain in Nonmotor Symptom Scale (NMSS) was lower in the carrier group of both SNPs than in the noncarrier group in PD patients (SC: -0.198, p : 023). Other nonmotor symptoms reflected by relevant rating scales showed negative results. As to comorbidity, no significant statistical significance was observed between the two SNPs and Charlson Comorbidity Index (CCI). In conclusion, we found less severe gastrointestinal dysfunctions of both IL-10 rs1800871 and rs1800872 carriers than noncarriers in PD.

Lactoferrin ameliorates dopaminergic neurodegeneration and motor deficits in MPTP-treated mice

Brain iron accumulation is common in patients with Parkinson's disease (PD). Iron chelators have been investigated for their ability to prevent neurodegenerative diseases with features of iron overload. Given the non-trivial side effects of classical iron chelators, lactoferrin (Lf), a multifunctional iron-binding globular glycoprotein, was screened to identify novel neuroprotective pathways against dopaminergic neuronal impairment. We found that Lf substantially ameliorated PD-like motor dysfunction in the subacute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD. We further showed that Lf could alleviate MPTP-triggered apoptosis of DA neurons, neuroinflammation, and histological alterations. As expected, we also found that Lf suppressed MPTP-induced excessive iron accumulation and the upregulation of divalent metal transporter (DMT1) and transferrin receptor (TFR), which is the main intracellular iron regulation protein, and subsequently improved the activity of several antioxidant enzymes. We probed further and determined that the neuroprotection provided by Lf was involved in the upregulated levels of brain-derived neurotrophic factor (BDNF), hypoxia-inducible factor 1α (HIF-1α) and its downstream protein, accompanied by the activation of extracellular regulated protein kinases (ERK) and cAMP response element binding protein (CREB), as well as decreased phosphorylation of c-Jun N-terminal kinase (JNK) and mitogen activated protein kinase (MAPK)/P38 kinase in vitro and in vivo. Our findings suggest that Lf may be an alternative safe drug in ameliorating MPTP-induced brain abnormalities and movement disorder.

Unexpected Exacerbation of Neuroinflammatory Response After a Combined Therapy in Old Parkinsonian Mice

The design of therapeutic strategies that focus on the repositioning of anti-inflammatory and antioxidant drugs are a great bet to slow down the progression of neurodegenerative disorders. Despite the fact that Parkinson’s disease (PD) is an age-related pathology, almost all experimental studies are carried out in young animals. Here, we evaluated the possible neuroprotective effect of the combination of the antioxidant N-acetylcysteine (NAC) and the anti-inflammatory HA-1077 in aged 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice (C57BL/6 mice, 20 months old), whose individual treatment has been shown to have neuroprotective effects in this Parkinsonism model. Interestingly, NAC+HA-1077-based treatment produced a significant increase in dopaminergic neuronal death accompanied by an increase in microglial and astroglial activation in the Substantia Nigra pars compacta (SNpc) and striatum of old-Parkinsonian mice compared to their control group. The astroglial response was also explored by co-immunostaining for GFAP and S100b together with p-JNK and it was found to be particularly exacerbated in the MPTP+NAC+HA-1077 group. The unexpected toxic effects found in the combined use of NAC and HA-1077 in old-Parkinsonian mice highlight the importance of taking into account that in elderly Parkinsonian patients the combination of some drugs (most of them used for other different age-related alterations) can have side effects that may result in the exacerbation of the neurodegenerative process.

Novel Factors of Viral Origin Inhibit TOR Pathway Gene Expression

Polydnaviruses (PDVs) are obligate symbionts of endoparasitoid wasps, which exclusively attack the larval stages of their lepidopteran hosts. The Polydnavirus is injected by the parasitoid female during oviposition to selectively infect host tissues by the expression of viral genes without undergoing replication. Toxoneuron nigriceps bracovirus (TnBV) is associated with Toxoneuron nigriceps (Hymenoptera: Braconidae) wasp, an endoparasitoid of the tobacco budworm larval stages, Heliothis virescens (Lepidoptera: Noctuidae). Previous studies showed that TnBV is responsible for alterations in host physiology. The arrest of ecdysteroidogenesis is the main alteration which occurs in last (fifth) instar larvae and, as a consequence, prevents pupation. TnBV induces the functional inactivation of H. virescens prothoracic glands (PGs), resulting in decreased protein synthesis and phosphorylation. Previous work showed the involvement of the PI3K/Akt/TOR pathway in H. virescens PG ecdysteroidogenesis. Here, we demonstrate that this cellular signaling is one of the targets of TnBV infection. Western blot analysis and enzyme immunoassay (EIA) showed that parasitism inhibits ecdysteroidogenesis and the phosphorylation of the two targets of TOR (4E-BP and S6K), despite the stimulation of PTTH contained in the brain extract. Using a transcriptomic approach, we identified viral genes selectively expressed in last instar H. virescens PGs, 48 h after parasitization, and evaluated expression levels of PI3K/Akt/TOR pathway genes in these tissues. The relative expression of selected genes belonging to the TOR pathway (tor, 4e-bp, and s6k) in PGs of parasitized larvae was further confirmed by qRT-PCR. The down-regulation of these genes in PGs of parasitized larvae supports the hypothesis of TnBV involvement in blocking ecdysteroidogenesis, through alterations of the PI3K/Akt/TOR pathway at the transcriptional level.

P38 Mitogen-activated Protein Kinase and Parkinson's Disease

Parkinson's disease, the second major neurodegenerative disease, has created a great impact on the elder people. Although the mechanisms underlying Parkinson's disease are not fully understood, considerable evidence suggests that neuro-inflammation, oxidative stress, mitochondrial dysfunction, cell proliferation, differentiation and apoptosis are involved in the disease. p38MAPK, an important member of the mitogen-activated protein family, controls several important functions in the cell, suggesting a potential pathogenic role in PD. This review provides a brief description of the role and mechanism of p38MAPK in Parkinson's disease.

Peripheral Inflammation Enhances Microglia Response and Nigral Dopaminergic Cell Death in an in vivo MPTP Model of Parkinson's Disease

The impact of systemic inflammation in nigral dopaminergic cell loss remains unclear. Here, we have investigated the role of peripheral inflammation induced by systemic lipopolysaccharide (LPS) administration in the MPTP-based model of Parkinson’s disease. Brain inflammation, microglia and astroglia activation, disruption of the blood–brain barrier (BBB) and integrity of the nigrostriatal dopaminergic system were evaluated in response to i.p. injection of LPS, MPTP or the combination of both. Our results showed that combinative treatment exacerbates microglia activation and enhances (i) the appearance of galectin-3-positive microglia, recently identified as microglial disease-associated phenotypic marker, (ii) the up-regulation of pro-inflammatory cytokines, (iii) the occurrence of A1 neurotoxic astrocytes, (iv) the breakdown of the BBB, and (v) the loss of dopaminergic neurons in the substantia nigra. Microglia activation was triggered earlier than other degenerative events, suggesting that over-activation of microglia (including different polarization states) may induce dopaminergic neuron loss by itself, initiating the endless cycle of inflammation/degeneration. Our study revitalizes the importance of peripheral inflammation as a potential risk factor for Parkinson’s disease and raises the possibility of using new anti-inflammatory therapies to improve the course of neurodegenerative diseases, including those directly aimed at modulating the deleterious activity of disease-associated microglia.

A Novel Synthetic Derivative of Phloroglucinol Inhibits Neuroinflammatory Responses Through Attenuating Kalirin Signaling Pathway in Murine BV2 Microglial Cells

Neuroinflammation has been implicated as an important factor in the neurodegenerative diseases, and multiple candidates with anti-inflammatory effects have been shown to be beneficial for the treatment of neurodegenerative diseases. Our previous study demonstrated that a novel synthetic phloroglucinol derivative from Lysidice rhodostegia roots (code name: Compound 21) exerted neuroprotective effect through suppressing neuroinflammation. The aim of this study was to reveal the underlying molecular mechanism. The results indicated that the anti-inflammatory effects of Compound 21 were mediated through suppression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation and the production of reactive oxygen species (ROS). Further study showed that this suppression on NADPH oxidase was mediated by inhibiting the translocation and activity of its subunit Rac1. It is well established that Rac1 activation is regulated by a variety of guanine nucleotide exchange factors (GEFs), so we tried to find out whether GEFs were involved in the anti-inflammatory effects of Compound 21. The results showed that Compound 21 treatment down-regulated the expression and activity of GEF Kalirin, thus modulating the activity of Rac1 GTPase. Altogether, our data suggested that Compound 21 exerted the anti-neuroinflammatory effect through suppressing Kalirin signaling pathways, decreasing Rac1-NADPH oxidase activation and the subsequent pro-inflammatory cytokine production. The present study provided solid evidence to support Compound 21 as a potential candidate of neuroinflammatory inhibitor. Moreover, our findings have shed new light on the role of Rac1 and GEF Kalirin in neuroinflammation, which provides potential targets for neuroinflammation-related diseases, such as neurodegenerative diseases.

In vivo neutralization of the protagonist role of macrophages during the chronic inflammatory stage of Huntington's disease

Neurodegenerative diseases, characterised by the progressive and selective neuronal death in the central nervous system, are frequently accompanied by an activated immune system. In Huntington’s disease (HD), clinical and animal studies show evidence of immune activity, along with hyper-reactive monocyte/macrophage responses, while application of immunosuppressive regimens have imparted beneficial effects to HD mice. These findings suggest a contributory role of the immune system in HD pathology, with immune-based interventions offering a potential therapeutic strategy. Herein, we show that peripheral and CNS immune system activity increased with disease progression in HD mouse models and defined the phenotype of the immune response. Additionally, the depletion of monocytes and macrophages in vivo, via clodronate liposome treatment, revealed a major contributory role of these innate immune cells to the chronic inflammatory milieu observed during the course of the disease. This suggests that peripheral immunomodulatory strategies targeting monocytes and macrophages could be relevant for HD.

Alzheimer´s Disease in the Perspective of Neuroimmunology

Background

Alzheimer's Disease (AD) is a severe neurodegenerative disorder that includes the occurrence of behavioral disorders as well as memory and cognitive impairment as major symptoms. AD affects around 12% of the aged population in the world. Considerable research efforts have pointed to the role of innate immunity as the main culprit in the pathogenesis of AD. In this context, and according to with our neuroimmunomodulation theory, microglial activation modifies the cross-talks between microglia and neurons. We postulated that glial activation triggered by "damage signals" activates a pathological molecular cascade that finally leads to hyperphosphorylation and oligomerization of the tau protein. Interestingly, these modifications correlate with the gradual cognitive impairment of patients with the AD. Microglial activation is determined by the nature and strength of the stimulus. In the AD, a continuous activation state of microglia appears to generate neuronal injury and neurodegeneration, producing the outflow of pathological tau from the inner of neurons to the extraneuronal space. Released tau, together with the contribution of ApoE4 protein, would then produce reactivation of microglia, thus inducing a positive feedback that stimulates the vicious cycle in neurodegeneration.

Conclusion

Nevertheless, from the pathophysiological perspective AD is significantly more than a loss of memory. In the initial stages of AD pathogenesis, variations in the dopaminergic pathway along with serotonin diminution play an important role. This may explain why depression is associated with the onset of AD. All these pathophysiological events take place together with immunomodulatory changes that trigger tau oligomerization in the course of neurofibrillary tangles formation. Interestingly, mood disorders appear to be followed by neuroinflammatory processes and structural/functional alterations that lead to cognitive impairment in the context of AD.

Targeting Transcription Factors for Cancer Treatment

Transcription factors are involved in a large number of human diseases such as cancers for which they account for about 20% of all oncogenes identified so far. For long time, with the exception of ligand-inducible nuclear receptors, transcription factors were considered as “undruggable” targets. Advances knowledge of these transcription factors, in terms of structure, function (expression, degradation, interaction with co-factors and other proteins) and the dynamics of their mode of binding to DNA has changed this postulate and paved the way for new therapies targeted against transcription factors. Here, we discuss various ways to target transcription factors in cancer models: by modulating their expression or degradation, by blocking protein/protein interactions, by targeting the transcription factor itself to prevent its DNA binding either through a binding pocket or at the DNA-interacting site, some of these inhibitors being currently used or evaluated for cancer treatment. Such different targeting of transcription factors by small molecules is facilitated by modern chemistry developing a wide variety of original molecules designed to specifically abort transcription factor and by an increased knowledge of their pathological implication through the use of new technologies in order to make it possible to improve therapeutic control of transcription factor oncogenic functions.