Combined therapy with m-TOR-dependent and -independent autophagy inducers causes neurotoxicity in a mouse model of Machado-Joseph disease

A major pathological hallmark in several neurodegenerative disorders, like polyglutamine disorders (polyQ), including Machado-Joseph disease (MJD), is the formation of protein aggregates. MJD is caused by a CAG repeat expansion in the ATXN3 gene, resulting in an abnormal protein, which is prone to misfolding and forms cytoplasmic and nuclear aggregates within neurons, ultimately inducing neurodegeneration. Treatment of proteinopathies with drugs that up-regulate autophagy has shown promising results in models of polyQ diseases. Temsirolimus (CCI-779) inhibits the mammalian target of rapamycin (m-TOR), while lithium chloride (LiCl) acts by inhibiting inositol monophosphatase, both being able to induce autophagy. We have previously shown that chronic treatment with LiCl (10.4 mg/kg) had limited effects in a transgenic MJD mouse model. Also, others have shown that CCI-779 had mild positive effects in a different mouse model of the disease. It has been suggested that the combination of mTOR-dependent and -independent autophagy inducers could be a more effective therapeutic approach. To further explore this avenue toward therapy, we treated CMVMJD135 transgenic mice with a conjugation of CCI-779 and LiCl, both at concentrations known to induce autophagy and not to be toxic. Surprisingly, this combined treatment proved to be deleterious to both wild-type (wt) and transgenic animals, failing to rescue their neurological symptoms and actually exerting neurotoxic effects. These results highlight the possible dangers of manipulating autophagy in the nervous system and suggest that a better understanding of the potential disruption in the autophagy pathway in MJD is required before successful long-term autophagy modulating therapies can be developed.Fundação para a Ciência e Tecnologia through the projects [FEDER/FCT, POCI/SAU-MMO/60412/2004], [PTDC/SAU-GMG/64076/2006]. This work was supported by Fundação para a Ciência e Tecnologi

Nucleus accumbens microcircuit underlying D2-MSN-Driven increase in motivation

Accepted manuscriptThe nucleus accumbens (NAc) plays a central role in reinforcement and motivation. Around 95% of the NAc neurons are medium spiny neurons (MSNs), divided into those expressing dopamine receptor D1 (D1R) or dopamine receptor D2 (D2R). Optogenetic activation of D2-MSNs increased motivation, whereas inhibition of these neurons produced the opposite effect. Yet, it is still unclear how activation of D2-MSNs affects other local neurons/interneurons or input terminals and how this contributes for motivation enhancement. To answer this question, in this work we combined optogenetic modulation of D2-MSNs with in loco pharmacological delivery of specific neurotransmitter antagonists in rats. First, we showed that optogenetic activation of D2-MSNs increases motivation in a progressive ratio (PR) task. We demonstrated that this behavioral effect relies on cholinergic-dependent modulation of dopaminergic signalling of ventral tegmental area (VTA) terminals, which requires D1R and D2R signalling in the NAc. D2-MSN optogenetic activation decreased ventral pallidum (VP) activity, reducing the inhibitory tone to VTA, leading to increased dopaminergic activity. Importantly, optogenetic activation of D2-MSN terminals in the VP was sufficient to recapitulate the motivation enhancement. In summary, our data suggests that optogenetic stimulation of NAc D2-MSNs indirectly modulates VTA dopaminergic activity, contributing for increased motivation. Moreover, both types of dopamine receptors signalling in the NAc are required in order to produce the positive behavioral effects.This work was developed under the scope of the project NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). Part of the work was supported by the Janssen Neuroscience Prize (1st edition) and by a BIAL Grant (30/2016). This work has been funded by FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the project POCI-01-0145-FEDER-007038 and of project POCI-01-0145-FEDER-016428info:eu-repo/semantics/publishedVersio

Endolysosomal degradation of Tau and its role in glucocorticoid-driven hippocampal malfunction

Emerging studies implicate Tau as an essential mediator of neuronal atrophy and cognitive impairment in Alzheimer's disease (AD), yet the factors that precipitate Tau dysfunction in AD are poorly understood. Chronic environmental stress and elevated glucocorticoids (GC), the major stress hormones, are associated with increased risk of AD and have been shown to trigger intracellular Tau accumulation and downstream Tau-dependent neuronal dysfunction. However, the mechanisms through which stress and GC disrupt Tau clearance and degradation in neurons remain unclear. Here, we demonstrate that Tau undergoes degradation via endolysosomal sorting in a pathway requiring the small GTPase Rab35 and the endosomal sorting complex required for transport (ESCRT) machinery. Furthermore, we find that GC impair Tau degradation by decreasing Rab35 levels, and that AAV-mediated expression of Rab35 in the hippocampus rescues GC-induced Tau accumulation and related neurostructural deficits. These studies indicate that the Rab35/ESCRT pathway is essential for Tau clearance and part of the mechanism through which GC precipitate brain pathology.work was supported by NIH grants R01NS080967and R21MH 104803 to C.L.W., Portuguese Foundation for Science & Technology (FCT) PhD fellowships to J. Vaz-Silva and T. Meira (PD/BD/105938/2014; PD/BD/113700/2015, respectively), and the following grants to I.S.: FCT Investigator grant IF/01799/2013, the Portuguese North Regional Operational Program (ON.2) under the National Strategic Reference Framework (QREN), through the European Regional Development Fund (FEDER), the Project Estratégico co-funded by FCT (PEst-C/SAU/LA 0026/2013) and the European Regional Development Fund COMPETE (FCOMP-01 -0124-FEDER-037298) as well as the project NORTE- 01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER)info:eu-repo/semantics/publishedVersio

Valorização comercial de uma amostra de própolis do Gerês (Portugal)

O própolis e um material resinoso produzido por abelhas a partir de exsudados de plantas. Tem vindo a ser considerado um produto de excelência visto exibir inúmeras propriedades biológicas[1] . Atualmente, a dimensão do mercado global do própolis e avaliado em cerca de 2300 toneladas e estima-se atingir as 2900 toneladas em 2021, revelando-se um mercado promissor para utilizações nas indústrias farmacêutica, cosmética, alimentar e na apiterapia [2]. Porem, própolis de diferentes regiões geográficas podem apresentar diferentes composições químicas e, portanto, um perfil de propriedades biológicas distinto e/ou atividades específicas com eficiências muito distintas

Valorização e potenciais aplicações de uma amostra de própolis português da Beira Alta

O própolis é um produto elaborado pelas abelhas a partir de exsudados de plantas, usado na proteção da colmeia[1]. Tem sido muito estudado e valorizado mundialmente pelas suas propriedades biológicas, como a antioxidante e antimicrobiana, atribuídas principalmente a uma composição química rica em compostos fenólicos. A existência de vários tipos de própolis – determinados por diferentes tipos de flora e clima - salienta a necessidade da sua caracterização química e biológica[1]. A padronização do própolis é também requerida pela sua potencial utilização nas indústrias farmacêutica, cosmética ou alimentar[2] . Neste trabalho estudou-se uma amostra de própolis português para verificar o potencial benefício da sua incorporação em produtos cosméticos. Partiu-se de uma amostra recolhida num apiário da Beira Alta (Pereiro), em 2015, e procedeu-se à sua extração e reconstituição em diferentes solventes (etanol 100 % e 70 % e propilenoglicol). Os extratos (P15.EE100, P15.EE70 e P15.PGE) foram analisados quanto ao seu conteúdo de compostos fenólicos e flavonóides totais por métodos espetrofotométricos. Adicionalmente, os constituintes fenólicos individuais de P15.EE100 foram elucidados por análise de cromatografia liquida por fase reversa, associada a detetor de arrastamento de díodos e a espetrómetro de massa com ionização por eletrospray (UHPLC-DAD-ESI-MSn). Na avaliação do potencial antioxidante recorreu-se à medição da atividade scavenging dos radicais 2,2-difenil-1-picrilhidrazilo e do anião superóxido. A atividade antimicrobiana foi avaliada pelo método de diluição em agar. P15.EE100 revelou maior teor de polifenóis e flavonóides totais e também melhor capacidade antioxidante. P15.EE100 exibiu melhor atividade antibacteriana, particularmente contra bactérias Gram-positivas; P15.EE100 e P15.EE70 revelaram idêntica atividade antifúngica, com um MIC de 500 μg.mL-1 . Paralelamente à análise laboratorial estudou-se a indústria e o mercado da cosmética (em particular o segmento natural e orgânico) e o mercado do própolis. Os dados revelam que, nos últimos 20 anos, a indústria cosmética apresentou uma taxa de crescimento de aproximadamente 4,5 % por ano. O mercado global do segmento natural e orgânico tem aumentado significativamente, prevendo-se um crescimento anual de 10 %[3] . Relativamente ao mercado do própolis, prevê-se uma taxa de crescimento de 2,2 % até 2021[4]. Conjugando a análise da indústria cosmética com os resultados laboratoriais obtidos, em particular as propriedades antimicrobianas e antioxidantes reveladas pelo própolis estudado, perspetiva-se a possibilidade da sua aplicação em cosméticos

Preclinical assessment of mesenchymal-stem-cell-based therapies in spinocerebellar ataxia type 3

The low regeneration potential of the central nervous system (CNS) represents a challenge for the development of new therapeutic strategies for neurodegenerative diseases, including spinocerebellar ataxias. Spinocerebellar ataxia type 3 (SCA3)—or Machado–Joseph disease (MJD)—is the most common dominant ataxia, being mainly characterized by motor deficits; however, SCA3/MJD has a complex and heterogeneous pathophysiology, involving many CNS brain regions, contributing to the lack of effective therapies. Mesenchymal stem cells (MSCs) have been proposed as a potential therapeutic tool for CNS disorders. Beyond their differentiation potential, MSCs secrete a broad range of neuroregulatory factors that can promote relevant neuroprotective and immunomodulatory actions in different pathophysiological contexts. The objective of this work was to study the effects of (1) human MSC transplantation and (2) human MSC secretome (CM) administration on disease progression in vivo, using the CMVMJD135 mouse model of SCA3/MJD. Our results showed that a single CM administration was more beneficial than MSC transplantation—particularly in the cerebellum and basal ganglia—while no motor improvement was observed when these cell-based therapeutic approaches were applied in the spinal cord. However, the effects observed were mild and transient, suggesting that continuous or repeated administration would be needed, which should be further tested.This research was funded by the National Ataxia Foundation (NAF) and by Portuguese national funds, through the Foundation for Science and Technology (FCT)—projects UIDB/50026/2020, UIDP/50026/2020, POCI-01-0145-FEDER-029206, and through the Santa Casa Neuroscience Awards (Santa Casa da Misericórdia Lisboa)—project MC-04/17. Additionally, this project was funded by the ICVS Scientific Microscopy Platform, a member of the national infrastructure PPBI—Portuguese Platform of Bioimaging (PPBI-POCI-01-0145-FEDER-022122). S.C.S. received an individual fellowship within the project TUBITAK/0007/2014. The FCT funded individual fellowships to J.S C., A.N.-C., B.M.- P., F.G.T., R.L., S.M., N.A.S., C.S.-C., and S.D.-S. (SFRH/BD/140624/2018, SFRH/BPD/118779/2016, SFRH/BD/120124/2016, SFRH/BPD/118408/2016, PD/BDE/127836/2016, CEECIND/01902/2017, CEECIND/04794/2017, CEECIND/03887/2017, and CEECIND/00685/2020)

Treating Parkinson's Disease with Human Bone Marrow Mesenchymal Stem Cell Secretome: A Translational Investigation Using Human Brain Organoids and Different Routes of In Vivo Administration.

peer reviewedParkinson's disease (PD) is the most common movement disorder, characterized by the progressive loss of dopaminergic neurons from the nigrostriatal system. Currently, there is no treatment that retards disease progression or reverses damage prior to the time of clinical diagnosis. Mesenchymal stem cells (MSCs) are one of the most extensively studied cell sources for regenerative medicine applications, particularly due to the release of soluble factors and vesicles, known as secretome. The main goal of this work was to address the therapeutic potential of the secretome collected from bone-marrow-derived MSCs (BM-MSCs) using different models of the disease. Firstly, we took advantage of an optimized human midbrain-specific organoid system to model PD in vitro using a neurotoxin-induced model through 6-hydroxydopamine (6-OHDA) exposure. In vivo, we evaluated the effects of BM-MSC secretome comparing two different routes of secretome administration: intracerebral injections (a two-site single administration) against multiple systemic administration. The secretome of BM-MSCs was able to protect from dopaminergic neuronal loss, these effects being more evident in vivo. The BM-MSC secretome led to motor function recovery and dopaminergic loss protection; however, multiple systemic administrations resulted in larger therapeutic effects, making this result extremely relevant for potential future clinical applications

Constitutive deficiency of the neurogenic hippocampal modulator AP2γ promotes anxiety-like behavior and cumulative memory deficits in mice from juvenile to adult periods

The transcription factor activating protein two gamma (AP2γ) is an important regulator of neurogenesis both during embryonic development as well as in the postnatal brain, but its role for neurophysiology and behavior at distinct postnatal periods is still unclear. In this work, we explored the neurogenic, behavioral, and functional impact of a constitutive and heterozygous AP2γ deletion in mice from early postnatal development until adulthood. AP2γ deficiency promotes downregulation of hippocampal glutamatergic neurogenesis, altering the ontogeny of emotional and memory behaviors associated with hippocampus formation. The impairments induced by AP2γ constitutive deletion since early development leads to an anxious-like phenotype and memory impairments as early as the juvenile phase. These behavioral impairments either persist from the juvenile phase to adulthood or emerge in adult mice with deficits in behavioral flexibility and object location recognition. Collectively, we observed a progressive and cumulative impact of constitutive AP2γ deficiency on the hippocampal glutamatergic neurogenic process, as well as alterations on limbic-cortical connectivity, together with functional behavioral impairments. The results herein presented demonstrate the modulatory role exerted by the AP2γ transcription factor and the relevance of hippocampal neurogenesis in the development of emotional states and memory processes.H2020 -“la Caixa” Foundation(101003187

Effect of Levodopa on Reward and Impulsivity in a Rat Model of Parkinson's Disease

The use of dopamine replacement therapies (DRT) in the treatment of Parkinson's disease (PD) can lead to the development of dopamine dysregulation syndrome (DDS) and impulse control disorders (ICD), behavioral disturbances characterized by compulsive DRT self-medication and development of impulsive behaviors. However, the mechanisms behind these disturbances are poorly understood. In animal models of PD, the assessment of the rewarding properties of levodopa (LD), one of the most common drugs used in PD, has produced conflicting results, and its ability to promote increased impulsivity is still understudied. Moreover, it is unclear whether acute and chronic LD therapy differently affects reward and impulsivity. In this study we aimed at assessing, in an animal model of PD with bilateral mesostriatal and mesocorticolimbic degeneration, the behavioral effects of LD therapy regarding reward and impulsivity. Animals with either sham or 6-hydroxydopamine (6-OHDA)-induced bilateral lesions in the substantia nigra pars compacta (SNc) and ventral tegmental area (VTA) were exposed to acute and chronic LD treatment. We used the conditioned place preference (CPP) paradigm to evaluate the rewarding effects of LD, whereas impulsive behavior was measured with the variable delay-to-signal (VDS) task. Correlation analyses between behavioral measurements of reward or impulsivity and lesion extent in SNc/VTA were performed to pinpoint possible anatomical links of LD-induced behavioral changes. We show that LD, particularly when administered chronically, caused the development of impulsive-like behaviors in 6-OHDA-lesioned animals in the VDS. However, neither acute or chronic LD administration had rewarding effects in 6-OHDA-lesioned animals in the CPP. Our results show that in a bilateral rat model of PD, LD leads to the development of impulsive behaviors, strengthening the association between DRT and DDS/ICD in PD.Portuguese Foundation for Science and Technology: Ciência 2007 Program and IF Development Grant (IF/00111/2013) to AJS, Portuguese Foundation for Science and Technology PhD scholarships attributed to MMC (SFRH/BD/51061/2010), FLC (SFRH/BD/47311/2008) and CS-C (SFRH/BD/51992/2012), and Post-Doctoral Fellowship to HL-A (SFRH/BPD/80118/2011). Neurochemical analysis was funded from ELKE/UOA: 11650. This article has been developed under the scope of the project NORTE-01-0145-FEDER-000013 and NORTE-01-0145-FEDER-000023, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). This work has been funded by FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the project POCI-01-0145-FEDER-007038info:eu-repo/semantics/publishedVersio