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Increasing efforts have been made to elucidate how genetic and environmental factors interact in Parkinson's disease (PD). In the present study, we assessed the development of symptoms on a genetic PD rat model that overexpresses human α-synuclein (Snca +/+ ) at a presymptomatic age, exposed to a pro-inflammatory insult by intraperitoneal injection of lipopolysaccharide (LPS), using immunohistology, high-dimensional flow cytometry, constant potential amperometry, and behavioral analyses. A single injection of LPS into WT and Snca +/+ rats triggered long-lasting increase in the activation of pro-inflammatory microglial markers, monocytes, and T lymphocytes. However, only LPS Snca +/+ rats showed dopaminergic neuronal loss in the substantia nigra pars compacta (SNpc), associated with a reduction in the release of evoked dopamine in the striatum. No significant changes were observed in the behavioral domain. We propose our double-hit animal as a reliable model to investigate the mechanisms whereby α-synuclein and inflammation interact to promote neurodegeneration in PD., (© 2024. The Author(s).)

Background: The growing diffusion of artificial intelligence, data science and digital health has highlighted the role of collection of data and biological samples, thus raising legal and ethical concerns regarding its use and dissemination. Further, the expansion of biobanking, from the basic collection of frozen specimens to the virtual biobanks of specimens and associated data that exist today, has given a revolutionary potential on healthcare systems, particularly in the field of neurological diseases, due to the inaccessibility of central nervous system and the need of non-invasive investigation approaches. Informed Consent (IC) is considered mandatory in all research studies and specimen collections, and must specifically take into account the ethical respect to the individuals to whom the used biological material and data belong., Methods: We evaluated the attitudes of patients with neurological diseases (NP) and healthy volunteers (HV) towards the donation of biological samples to a biobank for future research studies on neurological diseases, and limitations on the use of data, related to the requirements set by the General Data Protection Regulation (GDPR). The study involved a total of 1454 subjects, including 502 HVs and 952 NPs, recruited at Santa Lucia Foundation IRCCS, Rome, from 2020 to 2024., Results: We found that (i) almost all subjects agreed with the participation in biobanking (ii) and authorization to genetic studies (HV = 99.1%; NP = 98.3%); Regarding the return of results, (iii) we found a statistically significant difference between NP and HV, the latter preferring not to be informed of potential results (HV = 43%; NP = 11.3%; p < 0.0001); (iv) a small number limited the sharing inside European Union (EU) (HV = 4.6%; NP = 6.6%), whereas patients were more likely to refuse transfer outside EU (HV = 7.4%; NP = 10.7% p = 0.05); (v) nearly all patients agreed with the use of additional health data from EMR for research purposes (98.9%)., Conclusions: Consent for the donation of material for research purposes is crucial for biobanking and biomedical research studies that use biological material of human origin. Here, we have shown that choices regarding participation in a neurological biobank can be different between HVs and NPs, even if the benefit for research and scientific progress is recognized. NP have a strong interest in being informed of possible results but limit sharing of samples, highlighting a perception of greater individual or relative benefit, while HV prefer a wide dissemination and sharing of data but not to have the return of the results, favoring a possible benefit for society and knowledge. The results underline the need to carefully manage biological material and data collected in biobanks, in compliance with the GDPR and the specific requests of donors., (© 2024. The Author(s).)

Competing Interests: None

Mechanisms of tissue damage in Huntington's disease (HD) involve excitotoxicity, mitochondrial damage, and neuroinflammation, including microglia activation. CD47 is a membrane protein that interacts with the inhibitory immunoreceptor SIRPα. Engagement of SIRPα by CD47 provides a downregulatory signal that inhibits host cell phagocytosis, promoting a "don't-eat-me" signal. These proteins are involved in the immune response and are downmodulated in inflammatory diseases. The involvement of inflammation and of the inflammasome in HD has already been described. In this study, we focused on other factors that can be involved in the unregulated inflammatory response that accelerates and exacerbate the neurodegenerative process in HD. Our results show that CD47 on striatal neurons decreased in HD mice, while it increased in wild type mice with age. SIRPα, on the other hand, was present in neurons in the wild type and increases in the R6/2 mice at all stages. Recruitment of SIRPα and binding to CD47 promotes the activation through phosphorylating events of non-receptor protein tyrosine phosphatase SHP-1 and SHP-2 in neurons and microglia. SHP phosphatases are able to curb the activity of NLRP3 inflammasome thereby reducing the detrimental effect of neuroinflammation. Such activity is mediated by the inhibition (dephosphorylation) of the proteins signal transducer and activator of transcription (STAT). We found that activated SHP-1 was present in microglia and neurons of WT mice at 5 and 13 weeks, increasing with time; while in R6/2 it was not localized in neurons but only in microglia, where it decreases with time. Consequently, STAT1 was overexpressed in neurons of R6/2 mice, as an effect of lack of modulation by SHP-1. Thus, our results shed light on the pathophysiology of neuronal damage, on one hand, paving the way toward a modulation of signal transducer proteins by specific inhibitors to achieve neuroprotection in HD, on the other., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Paldino, Migliorato and Fusco.)

Background: The accumulation of α-synuclein (α-syn) fibrils in intraneuronal inclusions called Lewy bodies and Lewy neurites is a pathological signature of Parkinson's disease (PD). Although several aspects linked to α-syn-dependent pathology (concerning its spreading, aggregation, and activation of inflammatory and neurodegenerative processes) have been under intense investigation, less attention has been devoted to the real impact of α-syn overexpression on structural and functional properties of substantia nigra pars compacta (SNpc) dopamine (DA) neurons, particularly at tardive stages of α-syn buildup, despite this has obvious relevance to comprehending mechanisms beyond PD progression., Objectives: We aimed to determine the consequences of a prolonged α-syn overexpression on somatodendritic morphology and functions of SNpc DA neurons., Methods: We performed immunohistochemistry, stereological DA cell counts, analyses of dendritic arborization, ex vivo patch-clamp recordings, and in vivo DA microdialysis measurements in a 12- to 13-month-old transgenic rat model overexpressing the full-length human α-syn (Snca +/+ ) and age-matched wild-type rats., Results: Aged Snca +/+ rats have mild loss of SNpc DA neurons and decreased basal DA levels in the SN. Residual nigral DA neurons display smaller soma and compromised dendritic arborization and, in parallel, increased firing activity, switch in firing mode, and hyperexcitability associated with hypofunction of fast activating/inactivating voltage-gated K + channels and Ca 2+ - and voltage-activated large conductance K + channels. These intrinsic currents underlie the repolarization/afterhyperpolarization phase of action potentials, thus affecting neuronal excitability., Conclusions: Besides clarifying α-syn-induced pathological landmarks, such evidence reveals compensatory functional mechanisms that nigral DA neurons could adopt during PD progression to counteract neurodegeneration. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society., (© 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)

Parkinson's disease (PD) is a neurodegenerative disease characterized by the accumulation of alpha-synuclein, encoded by the SNCA gene. The main neuropathological hallmark of PD is the degeneration of dopaminergic neurons leading to striatal dopamine depletion. Trophic support by a neurotrophin called glial-derived neurotrophic factor (GDNF) is also lacking in PD. We performed immunohistochemical studies to investigate neuropathological changes in the basal ganglia of a rat transgenic model of PD overexpressing alfa-synuclein. We observed that neuronal loss also occurs in the dorsolateral part of the striatum in the advanced stages of the disease. Moreover, along with the degeneration of the medium spiny projection neurons, we found a dramatic loss of parvalbumin interneurons. A marked decrease in GDNF, which is produced by parvalbumin interneurons, was observed in the striatum and in the substantia nigra of these animals. This confirmed the involvement of the striatum in the pathophysiology of PD and the importance of GDNF in maintaining the health of the substantia nigra.

Huntington's disease (HD) is a neurodegenerative disease characterized by several symptoms encompassing movement, cognition, and behavior. The mutation of the IT15 gene encoding for the huntingtin protein is the cause of HD. Mutant huntingtin interacts with and impairs the function of several transcription factors involved in neuronal survival. Although many mechanisms determining neuronal death have been described over the years, the significant role of inflammation has gained momentum in the last decade. Drugs targeting the elements that orchestrate inflammation have been considered powerful tools to treat HD. In this review, we will describe the data supporting inflammasome and NLRP3 as a target of therapeutics to fight HD, deepening the possible mechanisms of action underlying these effects.

We aimed to investigate A2A receptors in the basal ganglia of a DYT1 mouse model of dystonia. A2A was studied in control Tor1a+/+ and Tor1a+/- knock-out mice. A2A expression was assessed by anti-A2A antibody immunofluorescence and Western blotting. The co-localization of A2A was studied in striatal cholinergic interneurons identified by anti-choline-acetyltransferase (ChAT) antibody. A2A mRNA and cyclic adenosine monophosphate (cAMP) contents were also assessed. In Tor1a+/+, Western blotting detected an A2A 45 kDa band, which was stronger in the striatum and the globus pallidus than in the entopeduncular nucleus. Moreover, in Tor1a+/+, immunofluorescence showed A2A roundish aggregates, 0.3-0.4 μm in diameter, denser in the neuropil of the striatum and the globus pallidus than in the entopeduncular nucleus. In Tor1a+/-, A2A Western blotting expression and immunofluorescence aggregates appeared either increased in the striatum and the globus pallidus, or reduced in the entopeduncular nucleus. Moreover, in Tor1a+/-, A2A aggregates appeared increased in number on ChAT positive interneurons compared to Tor1a+/+. Finally, in Tor1a+/-, an increased content of cAMP signal was detected in the striatum, while significant levels of A2A mRNA were neo-expressed in the globus pallidus. In Tor1a+/-, opposite changes of A2A receptors' expression in the striatal-pallidal complex and the entopeduncular nucleus suggest that the pathophysiology of dystonia is critically dependent on a composite functional imbalance of the indirect over the direct pathway in basal ganglia.

Pyroptosis is a type of cell death that is caspase-1 (Casp-1) dependent, which leads to a rapid cell lysis, and it is linked to the inflammasome. We recently showed that pyroptotic cell death occurs in Huntington's disease (HD). Moreover, we previously described the beneficial effects of a PARP-1 inhibitor in HD. In this study, we investigated the neuroprotective effect of Olaparib, an inhibitor of PARP-1, in the mouse model of Huntington's disease. R6/2 mice were administered Olaparib or vehicle from pre-symptomatic to late stages. Behavioral studies were performed to investigate clinical effects of the compound. Immunohistochemical and Western blotting studies were performed to evaluate neuroprotection and the impact of the compound on the pathway of neuronal death in the HD mice. Our results indicate that Olaparib administration starting from the pre-symptomatic stage of the neurodegenerative disease increased survival, ameliorated the neurological deficits, and improved clinical outcomes in neurobehavioral tests mainly by modulating the inflammasome activation. These results suggest that Olaparib, a commercially available drug already in use as an anti-neoplastic compound, exerts a neuroprotective effect and could be a useful pharmaceutical agent for Huntington's disease therapy.

Mechanisms of tissue damage in Huntington's disease involve excitotoxicity, mitochondrial damage, and neuroinflammation, including microglia activation. In the present study, we investigate the role of pyroptosis process in the striatal neurons of the R6/2 mouse model of Huntington's disease. Transgenic mice were sacrificed at 4 and 13 weeks of age. After sacrifice, histological and immunohistochemical studies were performed. We found that NLRP3 and Caspase-1 were intensely expressed in 13-week-old R6/2 mice. Moreover, NLRP3 expression levels were higher in striatal spiny projection neurons and in parvalbumin interneurons, which are prone to degenerate in HD., Competing Interests: The authors declare that they have no conflict of interest., (© The Author(s) 2020.)

Mechanisms of tissue damage in Huntington's disease involve excitotoxicity, mitochondrial damage, and inflammation, including microglia activation. Immunomodulatory and anti-protein aggregation properties of tetracyclines were demonstrated in several disease models. In the present study, the neuroprotective and anti-inflammatory effects of the tetracycline doxycycline were investigated in the mouse model of HD disease R6/2. Transgenic mice were daily treated with doxycycline 20 mg/kg, starting from 4 weeks of age. After sacrifice, histological and immunohistochemical studies were performed. We found that doxycycline-treated R6/2 mice survived longer and displayed less severe signs of neurological dysfunction than the saline-treated ones. Primary outcome measures such as striatal atrophy, neuronal intranuclear inclusions, and the negative modulation of microglial reaction revealed a neuroprotective effect of the compound. Doxycycline provided a significantly increase of activated CREB and BDNF in the striatal neurons, along with a down modulation of neuroinflammation, which, combined, might explain the beneficial effects observed in this model. Our findings show that doxycycline treatment could be considered as a valid therapeutic approach for HD.

Dystonia pathophysiology has been partly linked to downregulation and dysfunction ofdopamine D2 receptors in striatum. We aimed to investigate the possible morpho-structuralcorrelates of D2 receptor downregulation in the striatum of a DYT1 Tor1a mouse model. Adultcontrol Tor1a+/+ and mutant Tor1a+/- mice were used. The brains were perfused and free-floatingsections of basal ganglia were incubated with polyclonal anti-D2 antibody, followed by secondaryimmune-fluorescent antibody. Confocal microscopy was used to detect immune-fluorescent signals.The same primary antibody was used to evaluate D2 receptor expression by western blot. The D2receptor immune-fluorescence appeared circumscribed in small disks (0.3-0.5 μm diameter), likelyrepresenting D2 synapse aggregates, densely distributed in the striatum of Tor1a+/+ mice. In theTor1a+/- mice the D2 aggregates were significantly smaller (μm2 2.4 ± SE 0.16, compared to μm2 6.73± SE 3.41 in Tor1a+/+) and sparse, with ~30% less number per microscopic field, value correspondentto the amount of reduced D2 expression in western blotting analysis. In DYT1 mutant mice thesparse and small D2 synapses in the striatum may be insufficient to "gate" the amount ofpresynaptic dopamine release diffusing in peri-synaptic space, and this consequently may result ina timing and spatially larger nonselective sphere of influence of dopamine action., Competing Interests: The authors declare no conflict of interest.

Background: Along with conventional therapy, novel tools are being developed in balance training for the rehabilitation of persons with stroke sequelae. The efficacy of Computerized Balance Training thus far been the object of studies only in persons with chronic stroke., Objective: To investigate the effects of an early Computerized Balance Training on balance, walking endurance and independence in activities of daily living, in persons with mild hemiparesis in subacute phase., Methods: Thirty-two persons with a recent hemiparesis (within 4 weeks from stroke onset), able to maintain a standing position for at least 30 seconds, were randomly assigned to an experimental or control group. The control group (CG) were administered conventional physiotherapy of 40 minutes twice a day, 5 times a week for 4 weeks, while the experimental group (EG) underwent conventional physiotherapy 40 minutes once a day and Computerized Balance Training once a day, 5 times a week for 4 weeks. Outcomes were evaluated by means of Berg Balance Scale (BBS), Tinetti Balance Scale (TBS), Two Minutes Walk Test (2MWT), Barthel Index (BI) and stabilometric tests., Results: Twelve participants for each group completed the training. Each group experienced 8 dropouts. The mean age (years) was 58.1±20.4 for EG and 59.7±14,7 for CG; the days from stroke were respectively 27.9±15.5 and 20±11.7. The difference between the two groups was statistically significant in experimental group for BBS (p = 0.003), for TBS (p = 0.028), for Sensory Integration and Balance tests performed with closed eyes on steady (p = 0.009) or instable surface (p = 0.023). and for 2MWT (p = 0.008)., Conclusions: Computerized Balance Training is an effective therapeutic tool for balance and gait endurance improvement in persons with stroke in subacute phase.

Among the new rehabilitation strategies aimed at improving independent walking after stroke, the body weight-support training allows an early and controlled ambulatory training. To date, most available studies are based on treadmill body weight-support (BWS) training and involve patients with chronic stroke sequelae. In contrast, the effects of a BWS training performed on the ground in patients with subacute hemiparesis (stroke within 4 weeks), with significant gait deficiencies, is unknown. The primary aim of this study was to evaluate the efficacy of a rehabilitative program that combines conventional approach with an early overground body weight-support training, in terms of recovery of independent walking focussing on patients with subacute stroke. The secondary aim was to evaluate the impact of body weight-support also on functional mobility, overall disability, and gait endurance. A total of 37 participants were enrolled and randomized to experimental group or control group for the baseline evaluations. In the experimental group, body weight-supported overground walking was added to conventional physiotherapy for 4 weeks. The outcome measurements used were: Functional Ambulation Classification (FAC), Rivermead Mobility Index, Barthel Index, and the 6-minute Walk Test. At the evaluation 1 week after the end of the intervention period, experimental group reached a statistically significant increase of independent walking as detected by FAC (experimental group: 3 vs. control group: 2, P < 0.01). No differences were observed by the other evaluation outcome measures. We conclude that BWS training may be more effective than conventional therapy alone in improving walking autonomy in persons with subacute stroke.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disease due to an expansion of a trinucleotide repeats in IT15 gene encoding for the protein huntingtin. Motor dysfunction, cognitive decline, and psychiatric disorder are typical clinical signs of HD. In HD, mutated huntingtin causes a major loss of brain derived neurotrophic factor (BDNF), causing striatal atrophy. Moreover, a key involvement of BDNF was observed in the synaptic plasticity that controls the acquisition and/or consolidation of certain forms of memory. We studied changes in hippocampal BDNF and in CREB in the R6/2 mouse model of HD. Moreover, we investigated if the beneficial effects of systemically administered recombinant BDNF observed in the striatum and cortex had an effect also on the hippocampus. Osmotic minipumps that chronically released recombinant BDNF or saline solution from 4 weeks of age until euthanasia were implanted into R6/2 and wild type mice. Our data show that BDNF is severely decreased in the hippocampus of R6/2 mice, while BDNF treatment restored its physiological levels. Moreover, the chronic administration of recombinant BDNF promoted the increment of phosphorylated CREB protein. Our study demonstrates the involvement of hippocampus in the pathology of R6/2 model of HD and correlates the beneficial effects of BDNF administration with increased hippocampal levels of BDNF and pCREB.

Inflammation significantly impacts the progression of Huntington's disease (HD) and the mutant HTT protein determines a pro-inflammatory activation of microglia. Mesenchymal stem/stromal cells (MSC) from the amniotic membrane (hAMSC), and their conditioned medium (CM-hAMSC), have been shown to possess protective effects in vitro and in vivo in animal models of immune-based disorders and of traumatic brain injury, which have been shown to be mediated by their immunomodulatory properties. In this study, in the R6/2 mouse model for HD we demonstrate that mice treated with CM-hAMSC display less severe signs of neurological dysfunction than saline-treated ones. CM-hAMSC treatment significantly delayed the development of the hind paw clasping response during tail suspension, reduced deficits in rotarod performance, and decreased locomotor activity in an open field test. The effects of CM-hAMSC on neurological function were reflected in a significant amelioration in brain pathology, including reduction in striatal atrophy and the formation of striatal neuronal intranuclear inclusions. In addition, while no significant increase was found in the expression of BDNF levels after CM-hAMSC treatment, a significant decrease of microglia activation and inducible nitric oxide synthase levels were observed. These results support the concept that CM-hAMSC could act by modulating inflammatory cells, and more specifically microglia., (© 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Corticobasal degeneration (CBD) is a neurodegenerative disorder characterized by a combination of cortical and basal ganglia signs. We reported two cases treated with a bilateral upper limb rehabilitation tool with videogame based feedback for 3 time per week for 8 weeks. Both patients showed an improvement of pinch and grasp forces and motor function. However, both of them reported an increased upper limb pain. Bilateral upper limb mechanical device with exergame feedback was effective also in the two patients suffering of CBD for limiting the effects of apraxia by performing intensive purposeful task training.

Huntington's disease (HD) is a fatal neurodegenerative condition, due to a mutation in the IT15 gene encoding for huntingtin. Currently, disease-modifying therapy is not available for HD, and only symptomatic drugs are administered for the management of symptoms. In the last few years, preclinical and clinical studies have indicated that pharmacological strategies aimed at inhibiting cyclic nucleotide phosphodiesterase (PDEs) may develop into a novel therapeutic approach in neurodegenerative disorders. PDEs are a family of enzymes that hydrolyze cyclic nucleotides into monophosphate isoforms. Cyclic nucleotides are second messengers that transduce the signal of hormones and neurotransmitters in many physiological processes, such as protein kinase cascades and synaptic transmission. An alteration in their balance results in the dysregulation of different biological mechanisms (transcriptional dysregulation, immune cell activation, inflammatory mechanisms, and regeneration) that are involved in neurological diseases. In this review, we discuss the action of phosphodiesterase inhibitors and their role as therapeutic agents in HD., (© 2018 John Wiley & Sons Ltd.)

Neuroglobin (Ngb) is expressed in the central and peripheral nervous system, cerebrospinal fluid, retina, and endocrine tissues where it is involved in binding O 2 and other gasotransmitters. Several studies have highlighted its endogenous neuroprotective function. Huntington's disease (HD), a dominant hereditary disease, is characterized by the gradual loss of neurons in discrete areas of the central nervous system. We analyzed the expression of Ngb in the brain tissue of a mouse model of HD, in order to define the role of Ngb with respect to individual cell type vulnerability in HD and to gender and age of mice. Our results showed different expressions of Ngb among neurons of a specific region and between different brain regions. We evidenced a decreased intensity of Ngb at 13 weeks of age, compared to 7 weeks of age. The double immunofluorescence and fluorescence resonance energy transfer (FRET) experiments showed that the co-localization between Ngb and huntingtin at the subcellular level was not close enough to account for a direct interaction. We also observed a different expression of Ngb in the striatum, depending on the sex and age of animals. These findings provide the first experimental evidence for an adaptive response of Ngb in HD, suggesting that Ngb may exert neuroprotective effects in HD beyond its role in reducing sensitivity to oxidative stress.

Among several mechanisms underlying the well-known trophic and protective effects of 17β-estradiol (E2) in the brain, we recently reported that E2 induces the up-regulation of two anti-apoptotic and neuroprotectant proteins: huntingtin (HTT) and neuroglobin (NGB). Here, we investigate the role of this up-regulation. The obtained results indicate that E2 promotes NGB-HTT association, induces the localization of the complex at the mitochondria, and protects SK-N-BE neuroblastoma cells and murine striatal cells, which express wild-type HTT (i.e., polyQ 7 ), against H 2 O 2 -induced apoptosis. All E2 effects were completely abolished in HTT-knocked out SK-N-BE cells and in striatal neurons expressing the mutated form of HTT (mHTT; i.e., polyQ 111 ) typical of Huntington's disease (HD). As a whole, these data provide a new function of wild-type HTT which drives E2-induced NGB in mitochondria modulating NGB anti-apoptotic activity. This new function is lost by HTT polyQ pathological expansion. These data evidence the existence of a novel E2/HTT/NGB neuroprotective axis that may play a relevant role in the development of HD therapeutics.

Poly (ADP-ribose) polymerases (PARPs) are enzymes that catalyze ADP-ribose units transfer from NAD to their substrate proteins. It has been observed that PARP-1 is able to increase both post-ischemic and excitotoxic neuronal death. In fact, we have previously shown that, INO-1001, a PARP-1 inhibitor, displays a neuroprotective effect in the R6/2 model of Huntington's disease (HD). In this study, we investigated the effects of PARP-1-inhibition on modulation of phosphorylated c-AMP response element binding protein (pCREB) and CREB-binding protein (CBP) localization in the different striatal neuronal subsets. Moreover, we studied the neurodegeneration of those interneurons that are particularly vulnerable to HD such as parvalbuminergic and calretininergic, and of other subclasses of interneurons that are known to be resistant, such as cholinergic and somatostatinergic interneurons. Transgenic mice were treated with INO-1001 (10 mg/Kg daily) starting from 4 weeks of age. Double-label immunofluorescence was performed to value the distribution of CBP in ubiquitinated Neuronal intranuclear inclusions (NIIs) in the striatum. INO-1001-treated and saline-treated brain sections were incubated with: goat anti-choline acetyl transferase; goat anti-nitric oxide synthase; mouse anti-parvalbumin and mouse anti-calretinin. Morphometric evaluation and cell counts were performed. Our study showed that the PARP inhibitor has a positive effect in sparing parvalbumin and calretinin-containing interneurons of the striatum, where CREB was upregulated. Moreover, INO-1001 promoted CBP localization into the nuclei of the R6/2 mouse. The sum of our data corroborates the previous observations indicating PARP inhibition as a possible therapeutic tool to fight HD.

We report that changes of phosphodiesterase-10A (PDE10A) can map widespread functional imbalance of basal ganglia circuits in a mouse model of DYT1 dystonia overexpressing mutant torsinA. PDE10A is a key enzyme in the catabolism of second messenger cAMP and cGMP, whose synthesis is stimulated by D1 receptors and inhibited by D2 receptors preferentially expressed in striatoentopeducuncular/substantia nigra or striatopallidal pathways, respectively. PDE10A was studied in control mice (NT) and in mice carrying human wild-type torsinA (hWT) or mutant torsinA (hMT). Quantitative analysis of PDE10A expression was assessed in different brain areas by rabbit anti-PDE10A antibody immunohistochemistry and Western blotting. PDE10A-dependent cAMP hydrolyzing activity and PDE10A mRNA were also assessed. Striatopallidal neurons were identified by rabbit anti-enkephalin antibody.In NT mice, PDE10A is equally expressed in medium spiny striatal neurons and in their projections to entopeduncular nucleus/substantia nigra and to external globus pallidus. In hMT mice, PDE10A content selectively increases in enkephalin-positive striatal neuronal bodies; moreover, PDE10A expression and activity in hMT mice, compared with NT mice, significantly increase in globus pallidus but decrease in entopeduncular nucleus/substantia nigra. Similar changes of PDE10A occur in hWT mice, but such changes are not always significant. However, PDE10A mRNA expression appears comparable among NT, hWT, and hMT mice.In DYT1 transgenic mice, the inverse changes of PDE10A in striatoentopeduncular and striatopallidal projections might result over time in an imbalance between direct and indirect pathways for properly focusing movement. The decrease of PDE10A in the striatoentopeduncular/nigral projections might lead to increased intensity and duration of D1-stimulated cAMP/cGMP signaling; conversely, the increase of PDE10A in the striatopallidal projections might lead to increased intensity and duration of D2-inhibited cAMP/cGMP signaling. SIGNIFICANCE STATEMENT In DYT1 transgenic mouse model of dystonia, PDE10A, a key enzyme in cAMP and cGMP catabolism, is downregulated in striatal projections to entopeduncular nucleus/substantia nigra, preferentially expressing D1 receptors that stimulate cAMP/cGMP synthesis. Conversely, in DYT1 mice, PDE10A is upregulated in striatal projections to globus pallidus, preferentially expressing D2 receptors that inhibit cAMP/cGMP synthesis. The inverse changes to PDE10A in striatoentopeduncular/substantia nigra and striatopallidal pathways might tightly interact downstream to dopamine receptors, likely resulting over time to increased intensity and duration respectively of D1-stimulated and D2-inhibited cAMP/cGMP signals. Therefore, PDE10A changes in the DYT1 model of dystonia can upset the functional balance of basal ganglia circuits, affecting direct and indirect pathways simultaneously., (Copyright © 2017 the authors 0270-6474/17/372113-13$15.00/0.)

Huntington's disease (HD) is an autosomal-dominant rare inherited neurodegenerative disease characterized by a wide variety of symptoms encompassing movement, cognition and behaviour. The cause of the disease is a genetic mutation in the huntingtin protein. The mutation leads to an unstable CAG expansion, translated into a polyglutamine domain within the disease protein. Indeed, huntingtin has a CAG/polyglutamine expansion in the range of 6-39 units in normal individuals, whereas it reaches 39-180 units in HD patients. Mutant huntingtin interacts with and impairs the function of a number of transcription factors. Indeed, the expression and function of cAMP response element-binding protein (CREB) and the brain-derived neurotrophic factor (BDNF) are severely affected in HD. Drugs targeting CREB loss of function and BDNF decrease have been considered as powerful tools to treat HD. Recently, cyclic nucleotide phosphodiesterase (PDE) inhibitors have been shown to reduce striatal and cortical degeneration in transgenic mouse model of HD. The neuroprotective effect is due to the competency of PDE4, 5 and 10 inhibitors to positively modulate CREB and BDNF protein levels, both in striatum and cortex in HD models. In this chapter, we will summarize the data supporting the use of PDE inhibitors as a therapeutic approach to fight HD, deepening the possible mechanisms of action underlying these effects.