Alterações em componentes inibitórios ao longo do neurodesenvolvimento : efeitos preventivos do resveratrol em modelo animal de TEA

O transtorno do espectro autista (TEA) é uma desordem multifatorial complexa cuja fisiopatologia ainda não é completamente compreendida. Entretanto, algumas características, como as alterações nos componentes inibitórios encefálicos, se evidenciam nessa desordem. Dentre os principais fatores de risco ambientais para o TEA se destaca a exposição ao ácido valproico (VPA) durante a gestação, de forma que se utilizou o modelo animal baseado nessa abordagem para a obtenção dos dados experimentais. No Capítulo I, realizou-se um compilado de dados da literatura sobre o papel de fatores de transcrição (FTs) em diferentes desordens do neurodesenvolvimento; além disso, foram feitas análises, utilizando ferramentas de bioinformática, dos principais locais de expressão, bem como dos momentos de pico de expressão e das possíveis rotas de interação entre os FTs, incluindo os possíveis prejuízos induzidos pelo VPA. Essa análise contribuiu para a identificação de diversas hipóteses que poderiam estar associadas com danos observados na vida pós-natal. Sabendo-se que o VPA possui características pró-inflamatórias e pró-oxidantes, o resveratrol (RSV), polifenol com características anti-inflamatórias, antioxidantes e neuroprotetoras, surge como uma estratégia interessante de contraposição dessas características, viabilizando um estudo importante de vias envolvidas no TEA. No Capítulo II, foi possível observar que o VPA induziu vastas alterações na composição neuronal do córtex pré-frontal medial (CPFm) e, em menor escala, no hipocampo (HC), além de reduzir a expressão de receptor GABAA e das proteínas sinápticas neuroliguina-2 e gefirina. O tratamento com RSV foi capaz de prevenir, de forma geral, as alterações em neurônios totais e interneurônios GABAérgicos (IGs) no CPFm, porém não no HC. Além disso, o RSV também teve um efeito similar ao VPA na expressão de proteínas sinápticas no CPFm. Análises de bancos de dados de modelos animais em idade embrionária ressaltam alterações na maquinaria transcricional, metabolismo de carboidratos, metabolismo mitocondrial e ciclo celular, via da WNT, via da NOTCH e outros, sugerindo, junto ao Capítulo I, hipóteses referentes às ações do VPA e do RSV. No Capítulo III, foi observada uma expansão do dano hipocampal induzida pela exposição ao VPA, com descontinuidade do giro denteado e descompactação de CA1, além de alterações disseminadas na composição neuronal em todas as sub-regiões do HC. O RSV preveniu a alteração morfológica, além de equilibrar diversos parâmetros associados a IGs e neurônios totais. A exposição ao VPA induziu alterações na expressão de PTEN, AKT e CK2, não prevenidas por RSV. A partir destes dados, conclui-se que a exposição ao VPA pode desencadear alterações em etapas iniciais do desenvolvimento embrionário, com consequentes alterações pós-natais. Em animais jovens, foram observadas alterações em IGs, sinapses e receptor GABAA. Em animais adultos, o HC se destaca como uma região fortemente alterada, indicando um provável agravamento ao longo da vida. É provável que a ação preventiva do RSV ocorra por oposição ao VPA em vias de regulação da transcrição, metabolismo e outras, conforme apontam os Capítulos I e II. Dessa forma, observa-se que uma intervenção precoce é capaz de mudar o panorama de evolução da desordem, abrindo horizontes para estudos de novas abordagens no TEA.Autism spectrum disorder (ASD) is a complex multifactorial disorder whose pathophysiology is not yet fully understood. However, some characteristics, such as changes in brain inhibitory components, emerge in this disorder. Among the main environmental risk factors for ASD, exposure to valproic acid (VPA) during pregnancy stands out, so the animal model based on this approach was used to obtain the experimental data. In Chapter I, a compilation of data from the literature on the role of transcription factors (TFs) in different neurodevelopmental disorders was carried out, in addition, analyzes were conducted, using bioinformatics tools, of the main sites of expression, as well as the moments of peak expression and possible routes of interaction among TFs, including possible damage induced by VPA. This analysis contributed to the identification of several hypotheses that could be associated with the damage observed in postnatal life. Knowing that VPA has pro-inflammatory and pro-oxidant characteristics, resveratrol (RSV), a polyphenol with anti-inflammatory, antioxidant, and neuroprotective characteristics, appears as an interesting strategy to counteract these characteristics, enabling an important study of the pathways involved in ASD. In Chapter II, it was possible to observe that VPA induced vast changes in the neuronal composition of the medial prefrontal cortex (mPFC) and, to a lesser extent, in the hippocampus (HC), in addition to reducing the expression of GABAA receptor and synaptic proteins neuroligin-2 and gephyrin. Treatment with RSV was able to generally prevent changes in total neurons and GABAergic interneurons (GIs) in mPFC, but not in the HC. Furthermore, RSV also had a similar effect to VPA on the expression of synaptic proteins in the mPFC. Database analyzes of animal models at embryonic age highlight changes in transcriptional machinery, carbohydrate metabolism, mitochondrial metabolism, cell cycle, WNT pathway, NOTCH pathway, and others, suggesting, together with Chapter I, hypotheses regarding the actions of VPA and the RSV. In Chapter III, an expansion of the hippocampal damage induced by exposure to VPA was observed, with discontinuity of the dentate gyrus and decompaction of the CA1, in addition to widespread changes in neuronal composition in all HC subregions. RSV prevented the morphological change, in addition to balancing several parameters associated with IGs and total neurons. Exposure to VPA induced changes in the expression of PTEN, AKT and CK2, not prevented by RSV. From these data, it is concluded that exposure to VPA can trigger changes in early stages of embryonic development, with consequent postnatal changes. In young animals, changes were observed in GIs, synapses, and GABAA receptor. In adult animals, the HC stands out as a strongly altered region, indicating a probable worsening throughout life. It is likely that the preventive action of RSV occurs in opposition to VPA in transcriptional, metabolic, and other regulatory pathways, as indicated in Chapters I and II. In this way, it is observed that an early intervention can change the course of the disorder, opening horizons for studies of new approaches in ASD

Resveratrol prevents cytoarchitectural and interneuronal alterations in the valproic acid rat model of autism

Autism spectrum disorder (ASD) is a prevalent neurodevelopmental disorder characterized by several alterations, including disorganized brain cytoarchitecture and excitatory/inhibitory (E/I) imbalance. We aimed to analyze aspects associated with the inhibitory components in ASD, using bioinformatics to develop notions about embryonic life and tissue analysis for postnatal life. We analyzed microarray and RNAseq datasets of embryos from different ASD models, demonstrating that regions involved in neuronal development are affected. We evaluated the effect of prenatal treatment with resveratrol (RSV) on the neuronal organization and quantity of parvalbumin-positive (PV+), somatostatin-positive (SOM+), and calbindin-positive (CB+) GABAergic interneurons, besides the levels of synaptic proteins and GABA receptors in the medial prefrontal cortex (mPFC) and hippocampus (HC) of the ASD model induced by valproic acid (VPA). VPA increased the total number of neurons in the mPFC, while it reduced the number of SOM+ neurons, as well as the proportion of SOM+, PV+, and CB+ neurons (subregion-specific manner), with preventive effects of RSV. In summary, metabolic alterations or gene expression impairments could be induced by VPA, leading to extensive damage in the late developmental stages. By contrast, due to its antioxidant, neuroprotective, and opposite action on histone properties, RSV may avoid damages induced by VPA

Resveratrol prevents cellular and behavioral sensory alterations in the animal model of autism induced by valproic acid

Autism spectrum disorder (ASD) is characterized by impairments in both social communication and interaction and repetitive or stereotyped behaviors. Although its etiology remains unknown, genetic and environmental risk factors have been associated with this disorder, including the exposure to valproic acid (VPA) during pregnancy. Resveratrol (RSV) is an anti-inflammatory and antioxidant molecule known to prevent social impairments in the VPA animal model of autism. This study aimed to analyze the effects of prenatal exposure to VPA, as well as possible preventive effects of RSV, on sensory behavior, the localization of GABAergic parvalbumin (PV+) neurons in sensory brain regions and the expression of proteins of excitatory and inhibitory synapses. Pregnant rats were treated daily with RSV (3.6 mg/kg) from E6.5 to E18.5 and injected with VPA (600 mg/kg) in the E12.5. Male pups were analyzed in nest seeking behavior and in whisker nuisance task. At P30, the tissues were removed and analyzed by immunofluorescence and western blotting. Our data showed for the first time an altered localization of PV+-neurons in primary sensory cortex and amygdala. We also showed a reduced level of gephyrin in the primary somatosensory area of VPA animals. The treatment with RSV prevented all the aforementioned alterations triggered by VPA. Our data shed light on the relevance of sensory component in ASD and highlights the interplay between RSV and VPA animal model as an important tool to investigate the pathophysiology of ASD

Effects of single-dose antipurinergic therapy on behavioral and molecular alterations in the valproic acid-induced animal model of autism

Autism spectrum disorder (ASD) is characterized by deficits in communication and social interaction, restricted interests, and stereotyped behavior. Environmental factors, such as prenatal exposure to valproic acid (VPA), may contribute to the increased risk of ASD. Since disturbed functioning of the purinergic system has been associated with the onset of ASD and used as a potential therapeutic target for ASD in both clinical and preclinical studies, we analyzed the effects of suramin, a non-selective purinergic antagonist, on behavioral, molecular and immunological in an animal model of autism induced by prenatal exposure to VPA. Treatment with suramin (20 mg/kg, intraperitoneal) restored sociability in the three-chamber apparatus and decreased anxiety measured by elevated plus maze apparatus, but had no impact on decreased reciprocal social interactions or higher nociceptive threshold in VPA rats. Suramin treatment had no impact on VPA-induced upregulation of P2X4 and P2Y2 in hippocampus, and P2X4 in medial prefrontal cortex, but normalized an increased level of interleukin 6 (IL-6). Our results suggest an important role of purinergic modulation in behavioral, molecular, and immunological aberrations described in VPA model, and suggest that purinergic system might be a potential target for pharmacotherapy in preclinical studies of ASD

ATLANTIC-PRIMATES: a dataset of communities and occurrences of primates in the Atlantic Forests of South America

Primates play an important role in ecosystem functioning and offer critical insights into human evolution, biology, behavior, and emerging infectious diseases. There are 26 primate species in the Atlantic Forests of South America, 19 of them endemic. We compiled a dataset of 5,472 georeferenced locations of 26 native and 1 introduced primate species, as hybrids in the genera Callithrix and Alouatta. The dataset includes 700 primate communities, 8,121 single species occurrences and 714 estimates of primate population sizes, covering most natural forest types of the tropical and subtropical Atlantic Forest of Brazil, Paraguay and Argentina and some other biomes. On average, primate communities of the Atlantic Forest harbor 2 ± 1 species (range = 1–6). However, about 40% of primate communities contain only one species. Alouatta guariba (N = 2,188 records) and Sapajus nigritus (N = 1,127) were the species with the most records. Callicebus barbarabrownae (N = 35), Leontopithecus caissara (N = 38), and Sapajus libidinosus (N = 41) were the species with the least records. Recorded primate densities varied from 0.004 individuals/km 2 (Alouatta guariba at Fragmento do Bugre, Paraná, Brazil) to 400 individuals/km 2 (Alouatta caraya in Santiago, Rio Grande do Sul, Brazil). Our dataset reflects disparity between the numerous primate census conducted in the Atlantic Forest, in contrast to the scarcity of estimates of population sizes and densities. With these data, researchers can develop different macroecological and regional level studies, focusing on communities, populations, species co-occurrence and distribution patterns. Moreover, the data can also be used to assess the consequences of fragmentation, defaunation, and disease outbreaks on different ecological processes, such as trophic cascades, species invasion or extinction, and community dynamics. There are no copyright restrictions. Please cite this Data Paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data. © 2018 by the The Authors. Ecology © 2018 The Ecological Society of Americ

ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ