Publications by authors named "Fabio Blandini"

101 Publications

GBA Mutations Influence the Release and Pathological Effects of Small Extracellular Vesicles from Fibroblasts of Patients with Parkinson's Disease.

Int J Mol Sci 2021 Feb 23;22(4). Epub 2021 Feb 23.

Cellular and Molecular Neurobiology Unit, IRCCS Mondino Foundation, 27100 Pavia, Italy.

Heterozygous mutations in the GBA gene, encoding the lysosomal enzyme glucocerebrosidase (GCase), are the strongest known genetic risk factor for Parkinson's disease (PD). The molecular mechanisms underlying the increased PD risk and the variable phenotypes observed in carriers of different GBA mutations are not yet fully elucidated. Extracellular vesicles (EVs) have gained increasing importance in neurodegenerative diseases since they can vehiculate pathological molecules potentially promoting disease propagation. Accumulating evidence showed that perturbations of the endosomal-lysosomal pathway can affect EV release and composition. Here, we investigate the impact of GCase deficiency on EV release and their effect in recipient cells. EVs were purified by ultracentrifugation from the supernatant of fibroblast cell lines derived from PD patients with or without GBA mutations and quantified by nanoparticle tracking analysis. SH-SY5Y cells over-expressing alpha-synuclein (α-syn) were used to assess the ability of patient-derived small EVs to affect α-syn expression. We observed that defective GCase activity promotes the release of EVs, independently of mutation severity. Moreover, small EVs released from PD fibroblasts carrying severe mutations increased the intra-cellular levels of phosphorylated α-syn. In summary, our work shows that the dysregulation of small EV trafficking and alpha-synuclein mishandling may play a role in GBA-associated PD.
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http://dx.doi.org/10.3390/ijms22042215DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7927041PMC
February 2021

Facemasks and face recognition: Potential impact on synaptic plasticity.

Neurobiol Dis 2021 06 26;153:105319. Epub 2021 Feb 26.

Department of Clinical Science and Translational Medicine, University of Rome Tor Vergata, Rome, Italy.

Visual recognition of facial expression modulates our social interactions. Compelling experimental evidence indicates that face conveys plenty of information that are fundamental for humans to interact. These are encoded at neural level in specific cortical and subcortical brain regions through activity- and experience-dependent synaptic plasticity processes. The current pandemic, due to the spread of SARS-CoV-2 infection, is causing relevant social and psychological detrimental effects. The institutional recommendations on physical distancing, namely social distancing and wearing of facemasks are effective in reducing the rate of viral spread. However, by impacting social interaction, facemasks might impair the neural responses to recognition of facial cues that are overall critical to our behaviors. In this survey, we briefly review the current knowledge on the neurobiological substrate of facial recognition and discuss how the lack of salient stimuli might impact the ability to retain and consolidate learning and memory phenomena underlying face recognition. Such an "abnormal" visual experience raises the intriguing possibility of a "reset" mechanism, a renewed ability of adult brain to undergo synaptic plasticity adaptations.
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http://dx.doi.org/10.1016/j.nbd.2021.105319DOI Listing
June 2021

Profiling the Biochemical Signature of GBA-Related Parkinson's Disease in Peripheral Blood Mononuclear Cells.

Mov Disord 2021 Feb 22. Epub 2021 Feb 22.

Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy.

Background: GBA mutations are the commonest genetic risk factor for Parkinson's disease (PD) and also impact disease progression.

Objective: The objective of this study was to define a biochemical profile that could distinguish GBA-PD from non-mutated PD.

Methods: 29 GBA-PD, 37 non-mutated PD, and 40 controls were recruited; α-synuclein levels in plasma, exosomes, and peripheral blood mononuclear cells were analyzed, GCase and main GCase-related lysosomal proteins in peripheral blood mononuclear cells were measured.

Results: Assessment of plasma and exosomal α-synuclein levels did not allow differentiation between GBA-PD and non-mutated PD; conversely, measurements in peripheral blood mononuclear cells clearly distinguished GBA-PD from non-mutated PD, with the former group showing significantly higher α-synuclein levels, lower GCase activity, higher LIMP-2, and lower Saposin C levels.

Conclusion: We propose peripheral blood mononuclear cells as an easily accessible and manageable model to provide a distinctive biochemical profile of GBA-PD, potentially useful for patient stratification or selection in clinical trials. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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http://dx.doi.org/10.1002/mds.28496DOI Listing
February 2021

Gender biased neuroprotective effect of Transferrin Receptor 2 deletion in multiple models of Parkinson's disease.

Cell Death Differ 2020 Dec 16. Epub 2020 Dec 16.

Department of Molecular Genetics, Rotterdam, the Netherlands.

Alterations in the metabolism of iron and its accumulation in the substantia nigra pars compacta accompany the pathogenesis of Parkinson's disease (PD). Changes in iron homeostasis also occur during aging, which constitutes a PD major risk factor. As such, mitigation of iron overload via chelation strategies has been considered a plausible disease modifying approach. Iron chelation, however, is imperfect because of general undesired side effects and lack of specificity; more effective approaches would rely on targeting distinctive pathways responsible for iron overload in brain regions relevant to PD and, in particular, the substantia nigra. We have previously demonstrated that the Transferrin/Transferrin Receptor 2 (TfR2) iron import mechanism functions in nigral dopaminergic neurons, is perturbed in PD models and patients, and therefore constitutes a potential therapeutic target to halt iron accumulation. To validate this hypothesis, we generated mice with targeted deletion of TfR2 in dopaminergic neurons. In these animals, we modeled PD with multiple approaches, based either on neurotoxin exposure or alpha-synuclein proteotoxic mechanisms. We found that TfR2 deletion can provide neuroprotection against dopaminergic degeneration, and against PD- and aging-related iron overload. The effects, however, were significantly more pronounced in females rather than in males. Our data indicate that the TfR2 iron import pathway represents an amenable strategy to hamper PD progression. Data also suggest, however, that therapeutic strategies targeting TfR2 should consider a potential sexual dimorphism in neuroprotective response.
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http://dx.doi.org/10.1038/s41418-020-00698-4DOI Listing
December 2020

Potential therapeutic effects of polyphenols in Parkinson's disease: and pre-clinical studies.

Neural Regen Res 2021 Feb;16(2):234-241

Laboratory of Cellular and Molecular Neurobiology, IRCCS Mondino Foundation, Pavia, Italy.

Parkinson's disease is a neurodegenerative disorder characterized by a combination of severe motor and non-motor symptoms. Over the years, several factors have been discovered to play a role in the pathogenesis of this disease, in particular, neuroinflammation and oxidative stress. To date, the pharmacological treatments used in Parkinson's disease are exclusively symptomatic. For this reason, in recent years, the research has been directed towards the discovery and study of new natural molecules to develop potential neuroprotective therapies against Parkinson's disease. In this context, natural polyphenols have raised much attention for their important anti-inflammatory and antioxidant properties, but also for their ability to modulate protein misfolding. In this review, we propose to summarize the relevant in vivo and in vitro studies concerning the potential therapeutic role of natural polyphenols in Parkinson's disease.
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http://dx.doi.org/10.4103/1673-5374.290879DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7896204PMC
February 2021

An update on the use of non-ergot dopamine agonists for the treatment of Parkinson's disease.

Expert Opin Pharmacother 2020 Dec 17;21(18):2279-2291. Epub 2020 Aug 17.

Laboratory of Cellular and Molecular Neurobiology, IRCCS Mondino Foundation , Pavia, Italy.

Introduction: Long-term treatment of Parkinson's disease (PD) with levodopa is hampered by motor complications related to the inability of residual nigrostriatal neurons to convert levodopa to dopamine (DA) and use it appropriately. This generated a tendency to postpone levodopa, favoring the initial use of DA agonists, which directly stimulate striatal dopaminergic receptors. Use of DA agonists, however, is associated with multiple side effects and their efficacy is limited by suboptimal bioavailability.

Areas Covered: This paper reviewed the latest preclinical and clinical findings on the efficacy and adverse effects of non-ergot DA agonists, discussing the present and future of this class of compounds in PD therapy.

Expert Opinion: The latest findings confirm the effectiveness of DA agonists as initial treatment or adjunctive therapy to levodopa in advanced PD, but a more conservative approach to their use is emerging, due to the complexity and repercussions of their side effects. As various factors may increase the individual risk to side effects, assessing such risk and calibrating the use of DA agonists accordingly may become extremely important in the clinical management of PD, as well as the availability of new DA agonists with better profiles of safety and efficacy.
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http://dx.doi.org/10.1080/14656566.2020.1805432DOI Listing
December 2020

In vivo modeling of prodromal stage of Parkinson's disease.

J Neurosci Methods 2020 08 5;342:108801. Epub 2020 Jun 5.

Laboratory of Cellular and Molecular Neurobiology, IRCCS Mondino Foundation, Pavia, via Mondino 2, 27100 Pavia, Italy; Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy. Electronic address:

Parkinson's disease (PD) has a long prodromal period that precedes the appearance of typical motor symptoms. This phase is extremely heterogeneous and is characterized by a wide range of non-motor alterations including REM sleep behavior disorders, constipation, olfactory and urinary dysfunctions. The increasing clinical and experimental knowledge on prodromal PD has led to the development of novel animal models recapitulating this disease stage as well as to a new use and interpretation of existing models. Prodromal animal models of PD represent an important tool for testing new therapeutic strategies and shedding light on the early pathogenic steps that set the ground for the extensive dopaminergic cell death observed in the midbrain. This review summarizes the new insights that these models have provided into the comprehension of a complex and still unexplored stage of PD.
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http://dx.doi.org/10.1016/j.jneumeth.2020.108801DOI Listing
August 2020

Glucocerebrosidase Defects as a Major Risk Factor for Parkinson's Disease.

Front Aging Neurosci 2020 21;12:97. Epub 2020 Apr 21.

Laboratory of Cellular and Molecular Neurobiology, IRCCS Mondino Foundation, Pavia, Italy.

Heterozygous mutations of the GBA1 gene, encoding for lysosomal enzyme glucocerebrosidase (GCase), occur in a considerable percentage of all patients with sporadic Parkinson's disease (PD), varying between 8% and 12% across the world. Genome wide association studies have confirmed the strong correlation between PD and GBA1 mutations, pointing to this element as a major risk factor for PD, possibly the most important one after age. The pathobiological mechanisms underlying the link between a defective function of GCase and the development of PD are still unknown and are currently the focus of intense investigation in the community of pre-clinical and clinical researchers in the PD field. A major controversy regards the fact that, despite the unequivocal correlation between the presence of GBA1 mutations and the risk of developing PD, only a minority of asymptomatic carriers with GBA1 mutations convert to PD in their lifetime. GBA1 mutations reduce the enzymatic function of GCase, impairing lysosomal efficiency and the cellular ability to dispose of pathological alpha-synuclein. Changes in the cellular lipidic content resulting from the accumulation of glycosphingolipids, triggered by lysosomal dysfunction, may contribute to the pathological modification of alpha-synuclein, due to its ability to interact with cell membrane lipids. Mutant GCase can impair mitochondrial function and cause endoplasmic reticulum stress, thereby impacting on cellular energy production and proteostasis. Importantly, reduced GCase activity is associated with clear activation of microglia, a major mediator of neuroinflammatory response within the brain parenchyma, which points to neuroinflammation as a major consequence of GCase dysfunction. In this present review article, we summarize the current knowledge on the role of GBA1 mutations in PD development and their phenotypic correlations. We also discuss the potential role of the GCase pathway in the search for PD biomarkers that may enable the development of disease modifying therapies. Answering these questions will aid clinicians in offering more appropriate counseling to the patients and their caregivers and provide future directions for PD preclinical research.
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http://dx.doi.org/10.3389/fnagi.2020.00097DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7186450PMC
April 2020

Pathological remodelling of colonic wall following dopaminergic nigrostriatal neurodegeneration.

Neurobiol Dis 2020 06 21;139:104821. Epub 2020 Feb 21.

Unit of Histology and Medical Embryology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy; Interdepartmental Research Centre "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy. Electronic address:

Background And Aim: Patients with Parkinson's disease (PD) are often characterized by functional gastrointestinal disorders. Such disturbances can occur at all stages of PD and precede the typical motor symptoms of the disease by many years. However, the morphological alterations associated with intestinal disturbances in PD are undetermined. This study examined the remodelling of colonic wall in 6-hydroxydopamine (6-OHDA)-induced PD rats.

Methods: 8 weeks after 6-OHDA injection animals were sacrificed. Inflammatory infiltrates, collagen deposition and remodelling of intestinal epithelial barrier and tunica muscularis in the colonic wall were assessed by histochemistry, immunohistochemistry, immunofluorescence and western blot analysis.

Results: 6-OHDA rats displayed significant alterations of colonic tissues as compared with controls. Signs of mild inflammation (eosinophil infiltration) and a transmural deposition of collagen fibres were observed. Superficial colonic layers were characterized by severe morphological alterations. In particular, lining epithelial cells displayed a reduced claudin-1 and transmembrane 16A/Anoctamin 1 (TMEM16A/ANO1) expression; goblet cells increased their mucin expression; colonic crypts were characterized by an increase in proliferating epithelial cells; the density of S100-positive glial cells and vimentin-positive fibroblast-like cells was increased as well. Several changes were found in the tunica muscularis: downregulation of α-smooth muscle actin/desmin expression and increased proliferation of smooth muscle cells; increased vimentin expression and proliferative phenotype in myenteric ganglia; reduction of interstitial cells of Cajal (ICCs) density.

Conclusions: A pathological remodelling occurs in the colon of 6-OHDA rats. The main changes include: enhanced fibrotic deposition; alterations of the epithelial barrier; activation of mucosal defense; reduction of ICCs. These results indicate that central nigrostriatal denervation is associated with histological changes in the large bowel at mucosal, submucosal and muscular level. These alterations might represent morphological correlates of digestive symptoms in PD.
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http://dx.doi.org/10.1016/j.nbd.2020.104821DOI Listing
June 2020

Neuroprotective effects of lignan 7-hydroxymatairesinol (HMR/lignan) in a rodent model of Parkinson's disease.

Nutrition 2020 01 25;69:110494. Epub 2019 Apr 25.

Laboratory of Cell and Molecular Neurobiology, IRCCS "Mondino Foundation", Pavia, Italy. Electronic address:

Objectives: Parkinson's disease (PD) is a neurodegenerative disease characterized by loss of dopaminergic neurons in the Substantia Nigra pars compacta (SNc). The proinflammatory response can occur early in the disease, contributing to nigrostriatal degeneration. Identification of the new molecules, which are able to slow down the degenerative process associated with PD, represents one of the main interests. Recently, natural polyphenols, especially lignans, have raised attention for their anti-inflammatory, antioxidant, and estrogenic activity at a peripheral level. The aim of this study was to evaluate the central effects of chronic treatment with lignan 7-hydroxymatairesinol (HMR/lignan) on neurodegenerative, neuroinflammatory processes and motor deficits induced by a unilateral intrastriatal injection of 6-hydroxydopamine (6-OHDA) in rats to evaluate the potential neuroprotective properties of this compound.

Methods: Sprague-Dawley male rats underwent lignan (10 mg/kg) or vehicle treatment (oral) for 4 wk starting from the day of 6-OHDA injection. The degree of nigrostriatal damage was evaluated by immunohistochemistry. Moreover, we performed a quantitative and qualitative assessment of neuroinflammatory process, including phenotypic polarization of microglia and astrocytes. The motor performance was assessed by behavioral tests.

Results: We demonstrated that chronic treatment with HMR/lignan was able to slow down the progression of degeneration of striatal dopaminergic terminals in a rat model of PD, with a consequent improvement in motor performance. Nevertheless, the anti-inflammatory effect of HMR/lignan observed in SNc was not sufficient to protect dopaminergic cells bodies.

Conclusion: These results suggest intriguing properties of HMR/lignan at neuroprotective and symptomatic levels in the context of PD.
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http://dx.doi.org/10.1016/j.nut.2019.04.006DOI Listing
January 2020

Parkinson's Disease in Women and Men: What's the Difference?

J Parkinsons Dis 2019 ;9(3):501-515

Laboratory of Cellular and Molecular Neurobiology, IRCCS Mondino Foundation, Pavia, Italy.

Increasing evidence points to biological sex as an important factor in the development and phenotypical expression of Parkinson's disease (PD). Risk of developing PD is twice as high in men than women, but women have a higher mortality rate and faster progression of the disease. Moreover, motor and nonmotor symptoms, response to treatments and disease risk factors differ between women and men. Altogether, sex-related differences in PD support the idea that disease development might involve distinct pathogenic mechanisms (or the same mechanism but in a different way) in male and female patients. This review summarizes the most recent knowledge concerning differences between women and men in PD clinical features, risk factors, response to treatments and mechanisms underlying the disease pathophysiology. Unraveling how the pathology differently affect the two sexes might allow the development of tailored interventions and the design of innovative programs that meet the distinct needs of men and women, improving patient care.
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http://dx.doi.org/10.3233/JPD-191683DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6700650PMC
June 2020

Evolution of prodromal parkinsonian features in a cohort of mutation-positive individuals: a 6-year longitudinal study.

J Neurol Neurosurg Psychiatry 2019 10 20;90(10):1091-1097. Epub 2019 Jun 20.

Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK

Objectives: mutations are a frequent risk factor for Parkinson disease (PD). The aim of this study is to evaluate clinical features in a group of mutation-positive individuals over a 6-year follow-up.

Methods: This is a longitudinal study on a cohort of -positive carriers. We enrolled 31 patients with Gaucher disease type 1 (GD), 29 heterozygous carriers (Het group) and 30 controls (HC) at baseline and followed them for 6 years. We assessed baseline motor and non-motor signs of PD in all subjects using clinical questionnaires and scales (reduced Unified Multiple System Atrophy Rating Scale (UMSARS), Montreal Cognitive assessment (MoCA), University of Pennsylvania Smell Identification Test (UPSIT), REM Sleep Behavior Disorder screening questionnaire (RBDsq), Movement Disorders Society Unified Parkinson's Disease Rating Scale motor subscale (MDS-UPDRS III) and Beck Depression Inventory (BDI). We repeated these at the 6-year follow-up alongside venous blood sampling for measurement of glucocerebrosidase enzymatic activity (GCase). We explored whether the GCase activity level was altered in leucocytes of these subjects and how it was related to development of PD.

Results: We observed a significant worsening in UMSARS, RBDsq, MDS-UPDRS III and BDI scores at the 6-year follow-up compared with baseline in both the GD and Het groups. Intergroup comparisons showed that GD subjects had significantly worse scores in UPSIT, UMSARS, MoCA and MDS-UPDRS III than HC, while Het displayed worse outcomes in UPSIT and MDS-UPDRS III compared with HC. In mutation-positive individuals (Het and GD), an UPSIT score of 23 at baseline was correlated with worse outcome at 6 years in UPSIT, MoCA, MDS-UPDRS III and BDI.

Conclusion: In this 6-year-long longitudinal study, mutation-positive subjects showed a worsening in motor and non-motor prodromal PD features.
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http://dx.doi.org/10.1136/jnnp-2019-320394DOI Listing
October 2019

Peripheral-Central Neuroimmune Crosstalk in Parkinson's Disease: What Do Patients and Animal Models Tell Us?

Front Neurol 2019 19;10:232. Epub 2019 Mar 19.

Laboratory of Cellular and Molecular Neurobiology, IRCCS Mondino Foundation, Pavia, Italy.

The brain is no longer considered an immune privileged organ and neuroinflammation has long been associated with Parkinson's disease. Accumulating evidence demonstrates that innate and adaptive responses take place in the CNS. The extent to which peripheral immune alterations impacts on the CNS, or vice and versa, is, however, still a matter of debate. Gaining a better knowledge of the molecular and cellular immune dysfunctions present in these two compartments and clarifying their mutual interactions is a fundamental step in understanding and preventing Parkinson's disease (PD) pathogenesis. This review provides an overview of the current knowledge on inflammatory processes evidenced both in PD patients and in toxin-induced animal models of the disease. It discusses differences and similarities between human and animal studies in the context of neuroinflammation and immune responses and how they have guided therapeutic strategies to slow down disease progression. Future longitudinal studies are necessary and can help gain a better understanding on peripheral-central nervous system crosstalk to improve therapeutic strategies for PD.
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http://dx.doi.org/10.3389/fneur.2019.00232DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6433876PMC
March 2019

Glucocerebrosidase mutations and synucleinopathies: Toward a model of precision medicine.

Mov Disord 2019 01 27;34(1):9-21. Epub 2018 Dec 27.

Programa de Neurociencias, Fundación para la Investigación Médica Aplicada (FIMA), Universidad de Navarra, Pamplona, Spain.

Glucocerebrosidase is a lysosomal enzyme. The characterization of a direct link between mutations in the gene coding for glucocerebrosidase (GBA1) with the development of Parkinson's disease and dementia with Lewy bodies has heightened interest in this enzyme. Although the mechanisms through which glucocerebrosidase regulates the homeostasis of α-synuclein remains poorly understood, the identification of reduced glucocerebrosidase activity in the brains of patients with PD and dementia with Lewy bodies has paved the way for the development of novel therapeutic strategies directed at enhancing glucocerebrosidase activity and reducing α-synuclein burden, thereby slowing down or even preventing neuronal death. Here we reviewed the current literature relating to the mechanisms underlying the cross talk between glucocerebrosidase and α-synuclein, the GBA1 mutation-associated clinical phenotypes, and ongoing therapeutic approaches targeting glucocerebrosidase. © 2018 International Parkinson and Movement Disorder Society.
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http://dx.doi.org/10.1002/mds.27583DOI Listing
January 2019

Development and biochemical characterization of a mouse model of Parkinson's disease bearing defective glucocerebrosidase activity.

Neurobiol Dis 2019 04 4;124:289-296. Epub 2018 Dec 4.

Laboratory of Functional Neurochemistry, IRCCS Mondino Foundation, Pavia, Italy. Electronic address:

GBA1 gene encodes for the lysosomal membrane protein glucocerebrosidase (GCase). GBA1 heterozygous mutations profoundly impair GCase activity and are currently recognized as an important risk factor for the development of Parkinson's disease (PD). Deficits in lysosomal degradation pathways may contribute to pathological α-synuclein accumulation, thereby favoring dopaminergic neuron degeneration and associated microglial activation. However, the precise mechanisms by which GCase deficiency may influence PD onset and progression remain unclear. In this work we used conduritol-β-epoxide (CBE), a potent inhibitor of GCase, to induce a partial, systemic defect of GCase activity comparable to that associated with heterozygous GBA1 mutations, in mice. Chronic (28 days) administration of CBE (50 mg/kg, i.p.) was combined with administration of a classic PD-like inducing neurotoxin, such as MPTP (30 mg/kg, i.p. for 5 days). The aim was to investigate whether a pre-existing GCase defect may influence the effects of MPTP in terms of nigrostriatal damage, microglia activation and α-synuclein accumulation. Pre-treatment with CBE had tendency to enhance MPTP-induced neurodegeneration in striatum and caused significant increase of total α-synuclein expression in substantia nigra. Microglia was remarkably activated by CBE alone, without further increases when combined with MPTP. Overall, we propose this model as an additional tool to study pathophysiological processes of PD in the presence of GCase defects.
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http://dx.doi.org/10.1016/j.nbd.2018.12.001DOI Listing
April 2019

Activation of the DNA damage response in vivo in synucleinopathy models of Parkinson's disease.

Cell Death Dis 2018 07 26;9(8):818. Epub 2018 Jul 26.

Department of Molecular Genetics, Rotterdam, The Netherlands.

The involvement of DNA damage and repair in aging processes is well established. Aging is an unequivocal risk factor for chronic neurodegenerative diseases, underscoring the relevance of investigations into the role that DNA alterations may have in the pathogenesis of these diseases. Consistently, even moderate impairment of DNA repair systems facilitates the onset of pathological features typical of PD that include derangement of the dopaminergic system, mitochondrial dysfunction, and alpha-synuclein stress. The latter establishes a connection between reduced DNA repair capacity and a cardinal feature of PD, alpha-synuclein pathology. It remains to be determined, however, whether alpha-synuclein stress activates in vivo the canonical signaling cascade associated with DNA damage, which is centered on the kinase ATM and substrates such as γH2Ax and 53BP1. Addressing these issues would shed light on age-related mechanisms impinging upon PD pathogenesis and neurodegeneration in particular. We analyzed two different synucleinopathy PD mouse models based either on intranigral delivery of AAV-expressing human alpha-synuclein, or intrastriatal injection of human alpha-synuclein pre-formed fibrils. In both cases, we detected a significant increase in γH2AX and 53BP1 foci, and in phospho-ATM immunoreactivity in dopaminergic neurons, which collectively indicate DNA damage and activation of the DNA damage response. Mechanistic experiments in cell cultures indicate that activation of the DNA damage response is caused, at least in part, by pro-oxidant species because it is prevented by exogenous or endogenous antioxidants, which also rescue mitochondrial anomalies caused by proteotoxic alpha-synuclein. These in vivo and in vitro findings reveal that the cellular stress mediated by alpha-synuclein-a pathological hallmark in PD-elicits DNA damage and activates the DNA damage response. The toxic cascade leading to DNA damage involves oxidant stress and mitochondrial dysfunction The data underscore the importance of DNA quality control for preservation of neuronal integrity and protection against neurodegenerative processes.
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http://dx.doi.org/10.1038/s41419-018-0848-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6062587PMC
July 2018

Parkinson's disease patients have a complex phenotypic and functional Th1 bias: cross-sectional studies of CD4+ Th1/Th2/T17 and Treg in drug-naïve and drug-treated patients.

J Neuroinflammation 2018 Jul 12;15(1):205. Epub 2018 Jul 12.

Center of Research in Medical Pharmacology, University of Insubria, Via Ottorino Rossi n. 9, 21100, Varese, VA, Italy.

Background: Parkinson's disease (PD) affects an estimated 7 to 10 million people worldwide, and only symptomatic treatments are presently available to relieve the consequences of brain dopaminergic neurons loss. Neuronal degeneration in PD is the consequence of neuroinflammation in turn influenced by peripheral adaptive immunity, with CD4+ T lymphocytes playing a key role. CD4+ T cells may however acquire proinflammatory phenotypes, such as T helper (Th) 1 and Th17, as well as anti-inflammatory phenotypes, such as Th2 and the T regulatory (Treg) one, and to what extent the different CD4+ T cell subsets are imbalanced and their functions dysregulated in PD remains largely an unresolved issue.

Methods: We performed two cross-sectional studies in antiparkinson drug-treated and drug-naïve PD patients, and in age- and sex-matched healthy subjects. In the first one, we examined circulating Th1, Th2, Th17, and in the second one circulating Treg. Number and frequency of CD4+ T cell subsets in peripheral blood were assessed by flow cytometry and their functions were studied in ex vivo assays. In both studies, complete clinical assessment, blood count and lineage-specific transcription factors mRNA levels in CD4+ T cells were independently assessed and thereafter compared for their consistency.

Results: PD patients have reduced circulating CD4+ T lymphocytes, due to reduced Th2, Th17, and Treg. Naïve CD4+ T cells from peripheral blood of PD patients preferentially differentiate towards the Th1 lineage. Production of interferon-γ and tumor necrosis factor-α by CD4+ T cells from PD patients is increased and maintained in the presence of homologous Treg. This Th1-biased immune signature occurs in both drug-naïve patients and in patients on dopaminergic drugs, suggesting that current antiparkinson drugs do not affect peripheral adaptive immunity.

Conclusions: The complex phenotypic and functional profile of CD4+ T cell subsets in PD patients strengthen the evidence that peripheral adaptive immunity is involved in PD, and represents a target for the preclinical and clinical assessment of novel immunomodulating therapeutics.
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http://dx.doi.org/10.1186/s12974-018-1248-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6044047PMC
July 2018

The Exosomal/Total α-Synuclein Ratio in Plasma Is Associated With Glucocerebrosidase Activity and Correlates With Measures of Disease Severity in PD Patients.

Front Cell Neurosci 2018 18;12:125. Epub 2018 May 18.

Laboratory of Functional Neurochemistry, IRCCS Mondino Foundation Pavia, Italy.

Intensive research efforts in the field of Parkinson's disease (PD) are focusing on identifying reliable biomarkers which possibly help physicians in predicting disease onset, diagnosis, and progression as well as evaluating the response to disease-modifying treatments. Given that abnormal alpha-synuclein (α-syn) accumulation is a primary component of PD pathology, this protein has attracted considerable interest as a potential biomarker for PD. Alpha-synuclein can be detected in several body fluids, including plasma, where it can be found as free form or in association with exosomes, small membranous vesicles secreted by virtually all cell types. Together with α-syn accumulation, lysosomal dysfunctions seem to play a central role in the pathogenesis of PD, given the crucial role of lysosomes in the α-syn degradation. In particular, heterozygous mutations in the GBA1 gene encoding lysosomal enzyme glucocerebrosidase (GCase) are currently considered as the most important risk factor for PD. Different studies have found that GCase deficiency leads to accumulation of α-syn; whereas at the same time, increased α-syn may inhibit GCase function, thus inducing a bidirectional pathogenic loop. In this study, we investigated whether changes in plasma total and exosome-associated α-syn could correlate with disease status and clinical parameters in PD and their relationship with GCase activity. We studied 39 PD patients (mean age: 65.2 ± 8.9; men: 25), without GBA1 mutations, and 33 age-matched controls (mean age: 61.9 ± 6.2; men: 15). Our results showed that exosomes from PD patients contain a greater amount of α-syn compared to healthy subjects (25.2 vs. 12.3 pg/mL, < 0.001) whereas no differences were found in plasma total α-syn levels (15.7 vs. 14.8 ng/mL, = 0.53). Moreover, we highlighted a significant increase of plasma exosomal α-syn/total α-syn ratio in PD patients (1.69 vs. 0.89, < 0.001), which negatively correlates with disease severity ( = 0.014). Intriguingly, a significant inverse correlation between GCase activity and this ratio in PD subjects was found ( = 0.006). Additional and large-scale studies comparing GCase activity and pathological protein levels will be clearly needed to corroborate these data and determine whether the association between key players in the lysosomal system and α-syn can be used as diagnostic or prognostic biomarkers for PD.
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http://dx.doi.org/10.3389/fncel.2018.00125DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5968118PMC
May 2018

In vivo imaging of early signs of dopaminergic neuronal death in an animal model of Parkinson's disease.

Neurobiol Dis 2018 06 24;114:74-84. Epub 2018 Feb 24.

Center of Excellence for Neurodegenerative Diseases, Department of Oncology and Hemato-Oncology, University of Milan, Via Balzaretti 9, 20133 Milan, Italy. Electronic address:

The Parkinson's disease (PD) evolves over an extended period of time with the onset occurring long before clinical signs begin to manifest. Characterization of the molecular events underlying the PD onset is instrumental for the development of diagnostic markers and preventive treatments, progress in this field is hindered by technical limitations. We applied an imaging approach to demonstrate the activation of Nrf2 transcription factor as a hallmark of neurodegeneration in neurotoxin-driven models of PD. In dopaminergic SK-N-BE neuroblastoma cells, Nrf2 activation was detected in cells committed to die as proven by time lapse microscopy; in the substantia nigra pars compacta area of the mouse brain, the Nrf2 activation preceded dopaminergic neurodegeneration as demonstrated by in vivo and ex vivo optical imaging, a finding confirmed by co-localization experiments carried out by immunohistochemistry. Collectively, our results identify the Nrf2 signaling as an early marker of neurodegeneration, anticipating dopaminergic neurodegeneration and motor deficits.
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http://dx.doi.org/10.1016/j.nbd.2018.02.005DOI Listing
June 2018

Role of Autophagy in Parkinson's Disease.

Curr Med Chem 2019 ;26(20):3702-3718

Laboratory of Cellular and Molecular Neurobiology, IRCCS Mondino Foundation, Pavia, Italy.

Autophagy is an essential catabolic mechanism that delivers misfolded proteins and damaged organelles to the lysosome for degradation. Autophagy pathways include macroautophagy, chaperone-mediated autophagy and microautophagy, each involving different mechanisms of substrate delivery to lysosome. Defects of these pathways and the resulting accumulation of protein aggregates represent a common pathobiological feature of neurodegenerative disorders such as Alzheimer, Parkinson and Huntington disease. This review provides an overview of the role of autophagy in Parkinson's disease (PD) by summarizing the most relevant genetic and experimental evidence showing how this process can contribute to disease pathogenesis. Given lysosomes take part in the final step of the autophagic process, the role of lysosomal defects in the impairment of autophagy and their impact on disease will also be discussed. A glance on the role of non-neuronal autophagy in the pathogenesis of PD will be included. Moreover, we will examine novel pharmacological targets and therapeutic strategies that, by boosting autophagy, may be theoretically beneficial for PD. Special attention will be focused on natural products, such as phenolic compounds, that are receiving increasing consideration due to their potential efficacy associated with low toxicity. Although many efforts have been made to elucidate autophagic process, the development of new therapeutic interventions requires a deeper understanding of the mechanisms that may lead to autophagy defects in PD and should take into account the multifactorial nature of the disease as well as the phenotypic heterogeneity of PD patients.
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http://dx.doi.org/10.2174/0929867325666180226094351DOI Listing
October 2019

Mitochondrial Complex I Reversible S-Nitrosation Improves Bioenergetics and Is Protective in Parkinson's Disease.

Antioxid Redox Signal 2018 Jan 21;28(1):44-61. Epub 2017 Sep 21.

1 Department of Molecular Genetics, Erasmus MC , Rotterdam, The Netherlands .

Aims: This study was designed to explore the neuroprotective potential of inorganic nitrite as a new therapeutic avenue in Parkinson's disease (PD).

Results: Administration of inorganic nitrite ameliorates neuropathology in phylogenetically distinct animal models of PD. Beneficial effects are not confined to prophylactic treatment and also occur if nitrite is administered when the pathogenic cascade is already active. Mechanistically, the effect is mediated by both complex I S-nitrosation, which under nitrite administration is favored over formation of other forms of oxidation, and down-stream activation of the antioxidant Nrf2 pathway. Nitrite also rescues respiratory reserve capacity and increases proton leakage in LRRK2 PD patients' dermal fibroblasts.

Innovation: The study proposes an unprecedented approach based on the administration of the nitrosonium donor nitrite to contrast complex I and redox anomalies in PD. Dysfunctional mitochondrial complex I propagates oxidative stress in PD, and treatments mitigating this defect may, therefore, limit disease progression. Therapeutic complex I targeting has been successfully achieved in ischemia/reperfusion by using nitrosonium donors such as nitrite to reversibly modify its subunits and protect from oxidative damage after reperfusion. This evidence led to the innovative hypothesis that nitrite could exert protective effects also in pathological conditions where complex I dysfunction occurs in normoxia, such as in PD.

Conclusions: Overall, these results demonstrate that administration of inorganic nitrite improves mitochondrial function in PD, and it, therefore, represents an amenable intervention to hamper disease progression. Antioxid. Redox Signal. 28, 44-61.
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http://dx.doi.org/10.1089/ars.2017.6992DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5749586PMC
January 2018

Activation of the CREB/ Pathway during Long-Term Synaptic Plasticity in the Cerebellum Granular Layer.

Front Cell Neurosci 2017 28;11:184. Epub 2017 Jun 28.

Neurophysiology Unit, Department of Brain and Behavioral Sciences, University of PaviaPavia, Italy.

The induction of long-term potentiation and depression (LTP and LTD) is thought to trigger gene expression and protein synthesis, leading to consolidation of synaptic and neuronal changes. However, while LTP and LTD have been proposed to play important roles for sensori-motor learning in the cerebellum granular layer, their association with these mechanisms remained unclear. Here, we have investigated phosphorylation of the cAMP-responsive element binding protein (CREB) and activation of the immediate early gene pathway following the induction of synaptic plasticity by theta-burst stimulation (TBS) in acute cerebellar slices. LTP and LTD were localized using voltage-sensitive dye imaging (VSDi). At two time points following TBS (15 min and 120 min), corresponding to the early and late phases of plasticity, slices were fixed and processed to evaluate CREB phosphorylation (P-CREB) and c-FOS protein levels, as well as and mRNA expression. High levels of P-CREB and were detected before those of c-FOS, as expected if CREB phosphorylation triggered gene expression followed by protein synthesis. No differences between control slices and slices stimulated with TBS were observed in the presence of an N-methyl-D-aspartate receptor (NMDAR) antagonist. Interestingly, activation of the CREB/ system showed a relevant degree of colocalization with long-term synaptic plasticity. These results show that NMDAR-dependent plasticity at the cerebellum input stage bears about transcriptional and post-transcriptional processes potentially contributing to cerebellar learning and memory consolidation.
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http://dx.doi.org/10.3389/fncel.2017.00184DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5487453PMC
June 2017

Influence of Estrogen Modulation on Glia Activation in a Murine Model of Parkinson's Disease.

Front Neurosci 2017 31;11:306. Epub 2017 May 31.

Laboratory of Functional Neurochemistry, Center for Research in Neurodegenerative Diseases, C. Mondino National Neurological InstitutePavia, Italy.

Epidemiological data suggest a sexual dimorphism in Parkinson disease (PD), with women showing lower risk of developing PD. Vulnerability of the nigrostriatal pathway may be influenced by exposure to estrogenic stimulation throughout fertile life. To further address this issue, we analyzed the progression of nigrostriatal damage, microglia and astrocyte activation and microglia polarization triggered by intrastriatal injection of dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA) in male, female and ovariectomized (OVX) mice, as well as in OVX mice supplemented with 17βestradiol (OVX+E). Animals were sacrificed at different time points following 6-OHDA injection and brain sections containing striatum and substantia nigra pars compacta (SNc) underwent immunohistochemistry for tyrosine hydroxylase (TH) (dopaminergic marker), immunofluorescence for IBA1 and GFAP (markers of microglia and astrocyte activation, respectively) and triple immunoflorescent to identify polarization of microglia toward the cytotoxic M1 (DAPI/IBA1/TNFα) or cytoprotective M2 (DAPI/IBA1/CD206) phenotype. SNc damage induced by 6-OHDA was significantly higher in OVX mice, as compared to all other experimental groups, at 7 and 14 days after surgery. Astrocyte activation was higher in OVX mice with respect the other experimental groups, at all time points. Microglial activation in the SNc was detected at earlier time points in male, female and OVX+E, while in OVX mice was detected at all time-points. Microglia polarization toward the M2, but not the M1, phenotype was detected in female and OVX+E mice, while the M1 phenotype was observed only in male and OVX mice. Our results support the protective effects of estrogens against nigrostriatal degeneration, suggesting that such effects may be mediated by an interaction with microglia, which tend to polarize preferentially toward an M2, cytoprotective phenotype in the presence of intense estrogenic stimulation.
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http://dx.doi.org/10.3389/fnins.2017.00306DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5449471PMC
May 2017

Endothelial nitric oxide synthase inhibition triggers inflammatory responses in the brain of male rats exposed to ischemia-reperfusion injury.

J Neurosci Res 2018 01 13;96(1):151-159. Epub 2017 Jun 13.

Laboratory of Neurophysiology of Integrative Autonomic Systems, Headache Science Centre, "C. Mondino" National Neurological Institute, Pavia, Italy.

Nitric oxide (NO) derived from endothelial NO synthase (eNOS) plays a role in preserving and maintaining the brain's microcirculation, inhibiting platelet aggregation, leukocyte adhesion, and migration. Inhibition of eNOS activity results in exacerbation of neuronal injury after ischemia by triggering diverse cellular mechanisms, including inflammatory responses. To examine the relative contribution of eNOS in stroke-induced neuroinflammation, we analyzed the effects of systemic treatment with l-N-(1-iminoethyl)ornithine (L-NIO), a relatively selective eNOS inhibitor, on the expression of MiR-155-5p, a key mediator of innate immunity regulation and endothelial dysfunction, in the cortex of male rats subjected to transient middle cerebral artery occlusion (tMCAo) followed by 24 hr of reperfusion. Inducible NO synthase (iNOS) and interleukin-10 (IL-10) mRNA expression were evaluated by real-time polymerase chain reaction in cortical homogenates and in resident and infiltrating immune cells isolated from ischemic cortex. These latter cells were also analyzed for their expression of CD40, a marker of M1 polarization of microglia/macrophages.tMCAo produced a significant elevation of miR155-5p and iNOS expression in the ischemic cortex as compared with sham surgery. eNOS inhibition by L-NIO treatment further elevated the cortical expression of these inflammatory mediators, while not affecting IL-10 mRNA levels. Interestingly, modulation of iNOS occurred in resident and infiltrating immune cells of the ischemic hemisphere. Accordingly, L-NIO induced a significant increase in the percentage of CD40 events in CD68 microglia/macrophages of the ischemic cortex as compared with vehicle-injected animals. These findings demonstrate that inflammatory responses may underlie the detrimental effects due to pharmacological inhibition of eNOS in cerebral ischemia.
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http://dx.doi.org/10.1002/jnr.24101DOI Listing
January 2018

Investigational drugs in Phase I and Phase II for Levodopa-induced dyskinesias.

Expert Opin Investig Drugs 2017 Jul 1;26(7):777-791. Epub 2017 Jun 1.

a Laboratory of Functional Neurochemistry, Center for Research in Neurodegenerative Diseases , C. Mondino National Neurological Institute , Pavia , Italy.

Introduction: Prolonged treatment of Parkinson's disease (PD) with levodopa (L-DOPA) results in motor complications, including motor fluctuations and involuntary movements known as L-DOPA induced dyskinesias (LIDs). LIDs represent an additional cause of disability for PD patients and a major challenge for the clinical neurologist. Preclinical research has provided invaluable insights into the molecular and neural substrates of LIDs, identifying a number of potential targets for new anti-dyskinetic strategies. Areas covered: This review article is centered on drugs currently in Phase I and II clinical trials for LIDs and their relative pharmacological targets, which include glutamate, acetylcholine, serotonin, adrenergic receptors and additional targets of potential therapeutic interest. Expert opinion: LIDs are sustained by complex molecular and neurobiological mechanisms that are difficult to disentangle or target, unless one or more prevalent mechanisms are identified. In this context, the role of the serotonergic system and mGluR5 glutamate receptors seem to stand out. Interesting results have been obtained, for example, with partial 5-HT1A/5-HT1B receptor agonist eltoprazine and mGluR5 negative allosteric modulator dipraglurant. Confirmation of these results through large-scale, Phase III clinical trials will be needed, to obtain new pharmacological tools that may be used to optimize the treatment of PD patients with motor complications.
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http://dx.doi.org/10.1080/13543784.2017.1333598DOI Listing
July 2017

The Involvement of Post-Translational Modifications in Alzheimer's Disease.

Curr Alzheimer Res 2018 02;15(4):313-335

Laboratory of Pharmacology of Synaptic Disease, EBRI Rita Levi-Montalcini Foundation, Rome, Italy.

Background: Alzheimer's disease (AD) is a neurodegenerative disorder recognized as the most common cause of chronic dementia among the ageing population. AD is histopathologically characterized by progressive loss of neurons and deposits of insoluble proteins, primarily composed of amyloid-β pelaques and neurofibrillary tangles (NFTs).

Methods: Several molecular processes contribute to the formation of AD cellular hallmarks. Among them, post-translational modifications (PTMs) represent an attractive mechanism underlying the formation of covalent bonds between chemical groups/peptides to target proteins, which ultimately result modified in their function. Most of the proteins related to AD undergo PTMs. Several recent studies show that AD-related proteins like APP, Aβ, tau, BACE1 undergo post-translational modifications. The effect of PTMs contributes to the normal function of cells, although aberrant protein modification, which may depend on many factors, can drive the onset or support the development of AD.

Results: Here we will discuss the effect of several PTMs on the functionality of AD-related proteins potentially contributing to the development of AD pathology.

Conclusion: We will consider the role of Ubiquitination, Phosphorylation, SUMOylation, Acetylation and Nitrosylation on specific AD-related proteins and, more interestingly, the possible interactions that may occur between such different PTMs.
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http://dx.doi.org/10.2174/1567205014666170505095109DOI Listing
February 2018

Complex Changes in the Innate and Adaptive Immunity Accompany Progressive Degeneration of the Nigrostriatal Pathway Induced by Intrastriatal Injection of 6-Hydroxydopamine in the Rat.

Neurotox Res 2017 Jul 11;32(1):71-81. Epub 2017 Mar 11.

Laboratory of Functional Neurochemistry, Center for Research in Neurodegenerative Diseases, C. Mondino National Neurological Institute, Via Mondino, 2, 27100, Pavia, Italy.

We investigated changes in innate and adaptive immunity paralleling the progressive nigrostriatal damage occurring in a neurotoxic model of Parkinson's disease (PD) based on unilateral infusion of 6-hydroxydopamine (6-OHDA) into the rat striatum. A time-course analysis was conducted to assess changes in morphology (activation) and cell density of microglia and astrocytes, microglia polarization (M1 vs. M2 phenotype), lymphocyte infiltration in the lesioned substantia nigra pars compacta (SNc), and modifications of CD8+ and subsets of CD4+ T cell in peripheral blood accompanying nigrostriatal degeneration. Confirming previous results, we observed slightly different profiles of activation for astrocytes and microglia paralleling nigral neuronal loss. For astrocytes, morphological changes and cell density increases were mostly evident at the latest time points (14 and 28 days post-surgery), while moderate microglia activation was present since the earliest time point. For the first time, in this model, we described the time-dependent profile of microglia polarization. Activated microglia clearly expressed the M2 phenotype in the earlier phase of the experiment, before cell death became manifest, gradually shifting to the M1 phenotype as SNc cell death started. In parallel, a reduction in the percentage of circulating CD4+ T regulatory (Treg) cells, starting as early as day 3 post-6-OHDA injection, was detected in 6-OHDA-injected rats. Our data show that nigrostriatal degeneration is associated with complex changes in central and peripheral immunity. Microglia activation and polarization, Treg cells, and the factors involved in their cross-talk should be further investigated as targets for the development of therapeutic strategies for disease modification in PD.
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http://dx.doi.org/10.1007/s12640-017-9712-2DOI Listing
July 2017

Modulation of cerebral RAGE expression following nitric oxide synthase inhibition in rats subjected to focal cerebral ischemia.

Eur J Pharmacol 2017 Apr 8;800:16-22. Epub 2017 Feb 8.

Laboratory of Neurophysiology of Integrative Autonomic Systems, Headache Science Centre, "C. Mondino" National Neurological Institute, Pavia, Italy; Department of Brain and Behavioural Sciences, University of Pavia, Italy.

The receptor for advanced glycation endproducts (RAGE) is a key mediator of neuroinflammation following cerebral ischemia. Nitric oxide (NO) plays a dualistic role in cerebral ischemia, depending on whether it originates from neuronal, inducible or endothelial synthase. Although a dynamic interplay between RAGE and NO pathways exists, its relevance in ischemic stroke has not been investigated. The aim of this study is to evaluate the effect of the NO synthase (NOS) inhibition on RAGE expression in rats subjected to transient middle cerebral artery occlusion (tMCAo). Full-length (fl-RAGE) gene expression was elevated in the striatum and, to a lesser extent, in the cortex of rats undergone tMCAo. The exacerbation of cortical damage caused by systemic administration of L-N-(1-iminoethyl)ornithine (L-NIO), a relatively selective inhibitor of endothelial NOS (eNOS), was associated with elevated mRNA levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α and fl-RAGE in both the cortex and the striatum. Conversely, NG-nitro-l-arginine methyl ester (L-NAME), a non-selective NOS inhibitor, decreased cortical damage, did not affect cerebral cytokine mRNA levels, while it increased fl-RAGE mRNA expression only in the striatum. Fl-RAGE striatal protein levels varied accordingly with observed mRNA changes in the striatum, while in the cortex, RAGE protein levels were reduced by tMCAo and further decreased following L-NIO treatment. Modulation of RAGE expression by different inhibitors of NOS may have opposite effects on transient cortical ischemia: the non selective inhibition of NOS activity is protective, while the selective inhibition of eNOS is harmful, probably via the activation of inflammatory pathways.
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http://dx.doi.org/10.1016/j.ejphar.2017.02.008DOI Listing
April 2017

Effects of kynurenic acid analogue 1 (KYNA-A1) in nitroglycerin-induced hyperalgesia: Targets and anti-migraine mechanisms.

Cephalalgia 2017 Nov 16;37(13):1272-1284. Epub 2016 Nov 16.

1 Laboratory of Neurophysiology of Integrative Autonomic Systems, Headache Science Center, C. Mondino National Neurological Institute, Pavia, Italy.

Background Trigeminal sensitization represents a major mechanism underlying migraine attacks and their recurrence. Nitroglycerin (NTG) administration provokes spontaneous migraine-like headaches and in rat, an increased sensitivity to the formalin test. Kynurenic acid (KYNA), an endogenous regulator of glutamate activity and its analogues attenuate NTG-induced neuronal activation in the nucleus trigeminalis caudalis (NTC). The anti-hyperalgesic effect of KYNA analogue 1 (KYNA-A1) was investigated on animal models specific for migraine pain. Aim Rats made hyperalgesic by NTG administration underwent the plantar or orofacial formalin tests. The effect of KYNA-A1 was evaluated in terms of nocifensive behavior and of neuronal nitric oxide synthase (nNOS), calcitonin gene-related peptide (CGRP) and cytokines expression in areas involved in trigeminal nociception. Results KYNA-A1 abolished NTG-induced hyperalgesia in both pain models; NTG alone or associated to formalin injection induced an increased mRNA expression of CGRP, nNOS and cytokines in the trigeminal ganglia and central areas, which was reduced by KYNA-A1. Additionally, NTG caused a significant increase in nNOS immunoreactivity in the NTC, which was prevented by KYNA-A1. Conclusion Glutamate activity is likely involved in mediating hyperalgesia in an animal model specific for migraine. Its inhibition by means of a KYNA analogue modulates nNOS, CGRP and cytokines expression at peripheral and central levels.
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http://dx.doi.org/10.1177/0333102416678000DOI Listing
November 2017

Dopaminergic Receptors on CD4+ T Naive and Memory Lymphocytes Correlate with Motor Impairment in Patients with Parkinson's Disease.

Sci Rep 2016 Sep 22;6:33738. Epub 2016 Sep 22.

Center of Research in Medical Pharmacology, University of Insubria, Varese, Italy.

Parkinson's disease (PD) is characterized by loss of dopaminergic neurons in substantia nigra pars compacta, α-synuclein (α-syn)-rich intraneuronal inclusions (Lewy bodies), and microglial activation. Emerging evidence suggests that CD4+ T lymphocytes contribute to neuroinflammation in PD. Since the mainstay of PD treatment is dopaminergic substitution therapy and dopamine is an established transmitter connecting nervous and immune systems, we examined CD4+ T naive and memory lymphocytes in PD patients and in healthy subjects (HS), with specific regard to dopaminergic receptor (DR) expression. In addition, the in vitro effects of α-syn were assessed on CD4+ T naive and memory cells. Results showed extensive association between DR expression in T lymphocytes and motor dysfunction, as assessed by UPDRS Part III score. In total and CD4+ T naive cells expression of D-like DR decrease, while in T memory cells D-like DR increase with increasing score. In vitro, α-syn increased CD4+ T memory cells, possibly to a different extent in PD patients and in HS, and affected DR expression with cell subset-specific patterns. The present results support the involvement of peripheral adaptive immunity in PD, and may contribute to develop novel immunotherapies for PD, as well as to better use of current dopaminergic antiparkinson drugs.
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http://dx.doi.org/10.1038/srep33738DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5031979PMC
September 2016