75 research outputs found

    Living in Promiscuity: The Multiple Partners of Alpha-Synuclein at the Synapse in Physiology and Pathology.

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    Alpha-synuclein (α-syn) is a small protein that, in neurons, localizes predominantly to presynaptic terminals. Due to elevated conformational plasticity, which can be affected by environmental factors, in addition to undergoing disorder-to-order transition upon interaction with different interactants, α-syn is counted among the intrinsically disordered proteins (IDPs) family. As with many other IDPs, α-syn is considered a hub protein. This function is particularly relevant at synaptic sites, where α-syn is abundant and interacts with many partners, such as monoamine transporters, cytoskeletal components, lipid membranes, chaperones and synaptic vesicles (SV)-associated proteins. These protein⁻protein and protein⁻lipid membrane interactions are crucial for synaptic functional homeostasis, and alterations in α-syn can cause disruption of this complex network, and thus a failure of the synaptic machinery. Alterations of the synaptic environment or post-translational modification of α-syn can induce its misfolding, resulting in the formation of oligomers or fibrillary aggregates. These α-syn species are thought to play a pathological role in neurodegenerative disorders with α-syn deposits such as Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA), which are referred to as synucleinopathies. Here, we aim at revising the complex and promiscuous role of α-syn at synaptic terminals in order to decipher whether α-syn molecular interactants may influence its conformational state, contributing to its aggregation, or whether they are just affected by it

    Changes in α-Synuclein Posttranslational Modifications in an AAV-Based Mouse Model of Parkinson's Disease

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    Parkinson's disease (PD) pathology is characterized by the loss of dopaminergic neurons of the nigrostriatal system and accumulation of Lewy bodies (LB) and Lewy neurites (LN), inclusions mainly composed of alpha-synuclein (alpha-Syn) fibrils. Studies linking the occurrence of mutations and multiplications of the alpha-Syn gene (SNCA) to the onset of PD support that alpha-Syn deposition may play a causal role in the disease, in line with the hypothesis that disease progression may correlate with the spreading of LB pathology in the brain. Interestingly, LB accumulate posttranslationally modified forms of alpha-Syn, suggesting that alpha-Syn posttranslational modifications impinge on alpha-Syn aggregation and/or toxicity. Here, we aimed at investigating changes in alpha-Syn phosphorylation, nitration and acetylation in mice subjected to nigral stereotaxic injections of adeno-associated viral vectors inducing overexpression of human alpha-Syn (AAV-h alpha-Syn), that model genetic PD with SNCA multiplications. We detected a mild increase of serine (Ser) 129 phosphorylated alpha-Syn in the substantia nigra (SN) of AAV-h alpha-Syn-injected mice in spite of the previously described marked accumulation of this PTM in the striatum. Following AAV-h alpha-Syn injection, tyrosine (Tyr) 125/136 nitrated alpha-Syn accumulation in the absence of general 3-nitrotirosine (3NT) or nitrated-Tyr39 alpha-Syn changes and augmented protein acetylation abundantly overlapping with alpha-Syn immunopositivity were also detected

    The Contribution of -Synuclein Spreading to Parkinson’s Disease Synaptopathy

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    Synaptopathies are diseases with synapse defects as shared pathogenic features, encompassing neurodegenerative disorders such as Parkinson’s disease (PD). In sporadic PD, the most common age-related neurodegenerative movement disorder, nigrostriatal dopaminergic deficits are responsible for the onset of motor symptoms that have been related to -synuclein deposition at synaptic sites. Indeed, -synuclein accumulation can impair synaptic dopamine release and induces the death of nigrostriatal neurons. While in physiological conditions the protein can interact with and modulate synaptic vesicle proteins and membranes, numerous experimental evidences have confirmed that its pathological aggregation can compromise correct neuronal functioning. In addition, recent findings indicate that -synuclein pathology spreads into the brain and can affect the peripheral autonomic and somatic nervous system. Indeed, monomeric, oligomeric, and fibrillary -synuclein can move from cell to cell and can trigger the aggregation of the endogenous protein in recipient neurons. This novel “prion-like” behavior could further contribute to synaptic failure in PD and other synucleinopathies. This review describes the major findings supporting the occurrence of -synuclein pathology propagation in PD and discusses how this phenomenon could induce or contribute to synaptic injury and degeneration

    Blood baseline values in female alpine and nera di verzasca goats reared in italy.

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    The Italian goat autochthonous breeds are appreciated for their milk and characteristics, especially for the rusticity, frugality, fertility and longevity. For these reasons the local goat breeds play an important role in the livestock sector, and it is important to guarantee sanitary strategies control, prevention or treatment of diseases. It is well known that the hematological parameters in goats undergo changes in relation with many factors like breed, age (Piccione et al. 2014), physiological/reproductive status environmental factors and stress (Waziri M.A. et al. 2010).  Based on these differences it is necessary to establish appropriate physiological baseline values for every single breed which could be used in the realistic evaluation physiological or pathological status of the animal (Arfuso et al. 2016). The aim of this work was to evaluate the differences between a local goat breed (Verzasca) and a cosmopolite one (Alpine) from the hematological point of view, and to establish hematological reference values. A total number of 71 female goats, of Alpine (n=37), and Verzasca (n=34) were enrolled for this study, for a total of 716 blood samples. Data were processed by a mixed model-repeated measures ANCOVA in order to evaluate the effects of breed, parity, and season, while baseline values for each breed have been calculated by evaluating the 2.5-97.5th  percentile of variables distribution.The results showed that the breeds differ in a significant manner (Table 1). Verzasca goat shows significantly higher values in the erythroid parameters, whereas the Alpine goat shows higher mean values of leucocyte count and absolute neutrophil count. A further interesting result is the neutrophil lymphocyte ratio which is 0.96  in the Alpine and 0,57 in the Verzasca.The results here presented can add some knowledge to the definition of the health status of the two breeds, evidencing some environmental and physiological variation mechanisms.

    PTPN22 1858C>T Polymorphism Distribution in Europe and Association with Rheumatoid Arthritis: Case-Control Study and Meta-Analysis

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    The PTPN22 rs2476601 polymorphism is associated with rheumatoid arthritis (RA); nonetheless, the association is weaker or absent in some southern European populations. The aim of the study was to evaluate the association between the PTPN22 rs2476601 polymorphism and RA in Italian subjects and to compare our results with those of other European countries, carrying out a meta-analysis of European data

    Alpha-synuclein/synapsin III pathological interplay boosts the motor response to methylphenidate

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    : Loss of dopaminergic nigrostriatal neurons and fibrillary α-synuclein (α-syn) aggregation in Lewy bodies (LB) characterize Parkinson's disease (PD). We recently found that Synapsin III (Syn III), a phosphoprotein regulating dopamine (DA) release with α-syn, is another key component of LB fibrils in the brain of PD patients and acts as a crucial mediator of α-syn aggregation and toxicity. Methylphenidate (MPH), a monoamine reuptake inhibitor (MRI) efficiently counteracting freezing of gait in advanced PD patients, can bind α-syn and controls α-syn-mediated DA overflow and presynaptic compartmentalization. Interestingly, MPH results also efficient for the treatment of attention deficits and hyperactivity disorder (ADHD), a neurodevelopmental psychiatric syndrome associated with Syn III and α-syn polymorphisms and constituting a risk factor for the development of LB disorders. Here, we studied α-syn/Syn III co-deposition and longitudinal changes of α-syn, Syn III and DA transporter (DAT) striatal levels in nigrostriatal neurons of a PD model, the human C-terminally truncated (1-120) α-syn transgenic (SYN120 tg) mouse, in comparison with C57BL/6J wild type (wt) and C57BL/6JOlaHsd α-syn null littermates. Then, we analyzed the locomotor response of these animals to an acute administration of MPH (d-threo) and other MRIs: cocaine, that we previously found to stimulate Syn III-reliant DA release in the absence of α-syn, or the selective DAT blocker GBR-12935, along aging. Finally, we assessed whether these drugs modulate α-syn/Syn III interaction by fluorescence resonance energy transfer (FRET) and performed in silico studies engendering a heuristic model of the α-syn conformations stabilized upon MPH binding. We found that only MPH was able to over-stimulate a Syn III-dependent/DAT-independent locomotor activity in the aged SYN120 tg mice showing α-syn/Syn III co-aggregates. MPH enhanced full length (fl) α-syn/Syn III and even more (1-120) α-syn/Syn III interaction in cells exhibiting α-syn/Syn III inclusions. Moreover, in silico studies confirmed that MPH may reduce α-syn fibrillation by stabilizing a protein conformation with increased lipid binding predisposition. Our observations indicate that the motor-stimulating effect of MPH can be positively fostered in the presence of α-syn/Syn III co-aggregation. This evidence holds significant implications for PD and ADHD therapeutic management

    DOPAL initiates αSynuclein-dependent impaired proteostasis and degeneration of neuronal projections in Parkinson’s disease

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    Dopamine dyshomeostasis has been acknowledged among the determinants of nigrostriatal neuron degeneration in Parkinson’s disease (PD). Several studies in experimental models and postmortem PD patients underlined increasing levels of the dopamine metabolite 3,4-dihydroxyphenylacetaldehyde (DOPAL), which is highly reactive towards proteins. DOPAL has been shown to covalently modify the presynaptic protein αSynuclein (αSyn), whose misfolding and aggregation represent a major trait of PD pathology, triggering αSyn oligomerization in dopaminergic neurons. Here, we demonstrated that DOPAL elicits αSyn accumulation and hampers αSyn clearance in primary neurons. DOPAL-induced αSyn buildup lessens neuronal resilience, compromises synaptic integrity, and overwhelms protein quality control pathways in neurites. The progressive decline of neuronal homeostasis further leads to dopaminergic neuron loss and motor impairment, as showed in in vivo models. Finally, we developed a specific antibody which detected increased DOPAL-modified αSyn in human striatal tissues from idiopathic PD patients, corroborating the translational relevance of αSyn-DOPAL interplay in PD neurodegeneration

    Wilder than intense: higher frequency, variability, and viral flows of porcine circovirus 3 in wild boars and rural farms compared to intensive ones in northern Italy

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    IntroductionPorcine circovirus 3 (PCV-3) was firstly reported in 2017. Although evidence of its pathogenic role has been provided, its clinical relevance seems lower than Porcine circovirus 2 (PCV-2), as well as its evolutionary rate. Different studies have reported a high PCV-3 prevalence in wild boars, sometimes higher than the one observed in commercial pigs. Nevertheless, to date, few studies have objectively investigated the relationships between these populations when inhabiting the same area. Moreover, the role of small-scale, backyard pig production in PCV-3 epidemiology is still obscure.MethodsThe present study investigated PCV-3 occurrence in 216 samples collected from the same area of Northern Italy from commercial and rural pigs, and wild boars. PCV-3 presence was tested by qPCR and complete genome or ORF2 sequences were obtained when possible and analysed using a combination of statistical, phylogenetic and phylodynamic approaches.ResultsA higher infection risk in wild boars and rural pigs compared to the commercial ones was demonstrated. The phylodynamic analysis confirmed a larger viral population size in wild and rural populations and estimated a preferential viral flow from these populations to commercial pigs. A significant flow from wild to rural animals was also proven. The analysis of the Italian sequences and the comparison with a broader international reference dataset highlighted the circulation of a highly divergent clade in Italian rural pigs and wild boars only.DiscussionOverall, the present study results demonstrate the role of non-commercial pig populations in PCV-3 maintenance, epidemiology and evolution, which could represent a threat to intensive farming

    Acromegaly is associated with increased cancer risk: A survey in Italy

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    It is debated if acromegalic patients have an increased risk to develop malignancies. The aim of the present study was to assess the standardized incidence ratios (SIRs) of different types of cancer in acromegaly on a large series of acromegalic patients managed in the somatostatin analogs era. It was evaluated the incidence of cancer in an Italian nationwide multicenter cohort study of 1512 acromegalic patients, 624 men and 888 women, mean age at diagnosis 45 \uc2\ub1 13 years, followed up for a mean of 10 years (12573 person-years) in respect to the general Italian population. Cancer was diagnosed in 124 patients, 72 women and 52 men. The SIRs for all cancers was significantly increased compared to the general Italian population (expected: 88, SIR 1.41; 95% CI, 1.18-1.68, P < 0.001). In the whole series, we found a significantly increased incidence of colorectal cancer (SIR 1.67; 95% CI, 1.07-2.58, P = 0.022), kidney cancer (SIR 2.87; 95% CI, 1.55-5.34, P < 0.001) and thyroid cancer (SIR 3.99; 95% CI, 2.32-6.87, P < 0.001). The exclusion of 11 cancers occurring before diagnosis of acromegaly (all in women) did not change remarkably the study outcome. In multivariate analysis, the factors significantly associated with an increased risk of malignancy were age and family history of cancer, with a non-significant trend for the estimated duration of acromegaly before diagnosis. In conclusion, we found evidence that acromegaly in Italy is associated with a moderate increase in cancer risk
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