Exercício físico materno como estratégia neuroprotetora na Doença de Alzheimer

O período perinatal de desenvolvimento de um organismo é conhecido como janela crítica de susceptibilidade ou oportunidade, onde o fenótipo é estabelecido sob a influência do ambiente intrauterino ou da lactação. Dessa forma, o ambiente oferecido pelo estilo de vida materno influencia o desenvolvimento ao programar o metabolismo fetal. O exercício físico promove adaptações metabólicas, mesmo durante o período de gravidez, promovendo benefícios para o feto e contribuindo para a prevenção de doenças crônicas na vida adulta. Nesse sentido, o exercício materno afeta positivamente o metabolismo cerebral da prole, conferindo resistência às condições adversas no período pós-natal. No entanto, os mecanismos adaptativos envolvidos na determinação fenotípica do metabolismo da prole em resposta ao exercício materno ainda precisam ser determinados. A doença de Alzheimer é a principal doença neurodegenerativa associada com o envelhecimento, caracterizada por demência e declínio cognitivo. Bioquimicamente, o peptídeo β-amiloide tem papel relevante na neurotoxicidade característica da doença de Alzheimer. Em adição, o estresse oxidativo e a disfunção mitocondrial são algumas das características patofisiológicas dessa doença neurodegenerativa. A investigação de mecanismos envolvidos nesse processo é essencial para elucidar a origem e a evolução da doença, considerando o desafio do diagnóstico pré-clínico e o desenvolvimento de novas estratégias de tratamento. Na presente tese, foi investigado o papel neuroprotetor do exercício materno antes e durante a gestação contra as modificações neuroquímicas e comportamentais na prole adulta submetida à injeção intracerebroventricular de oligômeros de peptídeo β-amiloide, em um modelo animal da doença de Alzheimer. Inicialmente, avaliamos e descrevemos o comportamento materno, qualitativo e quantitativo, das ratas exercitadas (30 min/dia, 5 vezes/semana), bem como parâmetros de aparecimento das características físicas, dos reflexos motores e do desenvolvimento locomotor da prole. Além disso, investigamos algumas vias de sinalização associadas aos efeitos adaptativos do exercício materno no cérebro da prole aos 7 dias de vida pós-natal. Por fim, avaliamos o potencial do exercício materno em prevenir as alterações comportamentais, relacionadas às tarefas de aprendizado e memória, e neuroquímicas, relacionadas ao estado redox, função mitocondrial e função sináptica, induzidas pela neurotoxicidade de oligômeros de peptídeos β-amiloide 1-42 no córtex pré-frontal, hipocampo e cerebelo da prole adulta. Na presente tese, foi demonstrado que o exercício físico materno antes e durante a gestação não altera o comportamento materno, porém aumenta a frequência do comportamento exploratório da prole. A via da Akt-GSK-3β e as sirtuínas 1 e 3 são moduladas positivamente pelo exercício materno no cerebelo da prole. Interessantemente, o exercício materno preveniu diversas alterações neuroquímicas provocadas pela infusão de peptídeo β-amiloide1-42 oligomérico, como a redução de sinaptofisina e o aumento de Drp1 no hipocampo, o aumento dos níveis de espécies reativas, o aumento do imunoconteúdo da enzima óxido nítrico sintase e da proteína tau fosforilada no cerebelo da prole. Por fim, nossos resultados evidenciam o potencial efeito protetor do exercício físico materno contra prejuízos na memória induzidos pela infusão de peptídeo β-amiloide1-42 oligomérico na prole adulta ao modular positivamente a função mitocondrial. Os resultados apresentados ressaltam o potencial efeito neuroprotetor do exercício materno em um modelo animal, e essa abordagem baseada na mudança do estilo de vida pode ser extrapolada para a área clínica oferecendo a vantagem de prevenir o desenvolvimento de doenças crônicas na vida adulta.The perinatal period of development is known as a critical window of susceptibility or opportunity, in which the phenotype is stablished under the influence of intrauterine or lactational environment. Maternal lifestyle influences the development through programming the fetal metabolism. Physical exercise promotes metabolic adaptations, even during pregnancy, promoting benefits to the fetus and preventing chronic diseases in adulthood. In this way, maternal exercise positively affects offspring’s cerebral metabolism, conferring resistance to adverse conditions during postnatal life. However, the adaptive mechanisms involved in the phenotypical establishment of the offspring’s metabolism in response to maternal exercise remain to be elucidated. Alzheimer’s disease is the main aging-associated neurodegenerative disorder, psychologically characterized by dementia and cognitive decline. In this context, the amyloid-β peptide plays a significant role in the neurotoxicity of Alzheimer’s disease. In addition, the oxidative stress and mitochondrial dysfunction are also pathological features present in the disease. Investigating the underlying mechanisms is crucial to unveil the disease origin and progression, considering the challenging preclinical diagnosis and novel therapeutic strategies development. In this thesis, it was investigated the neuroprotective role of maternal exercise before and during pregnancy against neurochemical and behavioral alterations in the offspring injected with amyloid-β oligomers, in an Alzheimer’s disease-like model. Initially, we assessed and described the maternal behavior of exercised dams (30 min/day, 5 days/week); as well as the appearance of physical landmarks, motoric reflexes and ontogeny of locomotor behavior of female and male offspring. Furthermore, we assessed some signaling pathways related to adaptive effects of maternal exercise in the brain of 7-days-old pups. Finally, we assessed the potential effect of maternal exercise in preventing behavioral alterations, related to learning and memory tasks; as well as neurochemical changes, related to redox state, mitochondrial function and synaptic function, induced by neurotoxic infusion of oligomeric amyloid-β peptide 1-42 in the adult offspring’s prefrontal cortex, hippocampus and cerebellum. Herein, we demonstrated that maternal exercise before and during pregnancy does not alter maternal behavior but increases offspring’s exploratory behavior. The Akt-GSK-3β and sirtuin 1 and 3 pathways were positively modulated by maternal exercise in the offspring’s cerebellum. Strikingly, maternal exercise prevented several neurochemical alterations elicited by the infusion of oligomeric amyloid-β peptide, such as the reduction of synaptophysin immunocontent and the increase of Drp1 in the offspring’s hippocampus, the rise of reactive species, the immunocontent of the inducible nitric oxide synthase enzyme and tau phosphorylated in the offspring’s cerebellum. Our findings also evidence the protective effect of maternal exercise against memory impairment induced by amyloid-β peptide infusion in the adult offspring, by modulating mitochondrial function. The results presented here highlight the potential neuroprotective effect of maternal exercise in an animal model, and this approach based on the lifestyle change can be extrapolated to the clinical area by offering the advantageous to prevent the development of chronic diseases in adulthood

Obtenção de plasma rico em plaquetas: avaliação do efeito da centrifugação sobre a concentração de plaquetas através da comparação entre protocolos

The most different areas of health sciences seek to find new biotechnologies, in order to use them in tissue bioengineering. In this context, is inserted the platelet-rich plasma, who consists in high platelet concentration in a small volume of plasma, which is a potential method to provide a complex of growth factors that leads to repair of different tissues in medicine regenerative. The aim of this study was to assess the centrifugation effect (spin x time) on the platelet concentration, through comparison of three different protocols for producing platelet-rich plasma. Whole blood was drawn into tubes containing acid citrate dextrose as anticoagulant from ten healthy volunteers. The blood was divided into four aliquots for producing platelet-rich plasma by three different protocols and baseline platelet counts. All the protocols used were effective to concentrate platelets at least three times more than baseline values, however there was no statistically significant difference in the results of platelet concentration between the protocols for analysis of variance (p < 0,445). Regression analysis performed was able to predict the relationships between variables with significant positive correlation between the increases in the number of platelets. Protocols that used longer centrifugation time had a positive correlation between the number of baseline platelets count and the increases in platelets count after obtaining PRP.Diferentes áreas das ciências da saúde buscam encontrar novas biotecnologias, a fim de empregá-las na bioengenharia tecidual. Nesse contexto, está inserido o plasma rico em plaquetas, que consiste em um pequeno volume de plasma contendo alta concentração de plaquetas, e se trata de um método potencial para fornecer um complexo de fatores de crescimento que favorecem o reparo de diferentes tecidos no âmbito da medicina regenerativa. O objetivo do estudo foi avaliar o efeito da centrifugação (velocidade x tempo) sobre a concentração de plaquetas, através da comparação de três diferentes protocolos de obtenção de plasma rico em plaquetas. Foi coletado sangue total em tubos contendo o anticoagulante ácido citrato dextrose (ACD) de dez indivíduos voluntários. O sangue foi separado em quatro alíquotas, destinadas ao processamento do plasma rico em plaquetas por três diferentes protocolos e à contagem basal de plaquetas. Todos os protocolos testados foram eficazes para concentrar as plaquetas em pelo menos três vezes mais do que os valores basais, porém não houve diferença estatisticamente significante entre os resultados de concentração de plaquetas entre os protocolos por análise de variância (p < 0,445). A análise de regressão realizada foi capaz de predizer as relações entre as variáveis com correlação positiva significativa entre o aumento do número de plaquetas. Os protocolos que utilizaram maior tempo de centrifugação obtiveram correlação positiva entre o número basal de plaquetas e o aumento do número de plaquetas após a obtenção do PRP.

Modelo experimental em ratos no reparo ósseo do fêmur utilizando células mononucleares no plasma rico em plaquetas

As células mononucleares da medula óssea têm sido utilizadas em diversas afecções na tentativa de regeneração tecidual. (O objetivo deste estudo foi o de avaliar a adesão das células mononucleares sobre defeito crítico, com a adição do plasma rico em plaquetas (PRP) e / ou TGF-β1 (Fator de crescimento transformador Beta 1), e, por fim, verificar o reparo ósseo dos sítios defeituosos dos fêmures dos ratos. Foi criado um defeito bilateral critico nos fêmures de 33 Wistar-Kyoto ratos. Células mononucleares de medula óssea, TGF-β e PRP foram adicionadas no lado tratado da lesão e soro fisiológico no lado contralateral. Determinou-se a adesão de células mononucleares sobre o defeito crítico e reparo ósseo. A presença e consequente adesão das células mononucleares administradas nos animais tratados não foi evidenciada através da técnica de PCR. As análises radiológicas evidenciam fechamento da lesão, porém, nós não podemos afirmar que foi pelos tratamentos administrados ou pela própria regeneração óssea, quando analisadas em seis e 10 semanas pós-operatórias, haja visto não apresentarem diferenças significantes entre os grupos. Conclusões: a) As células mononucleares não aderiram ao defeito crítico criado no fêmur do rato; b) Não foi possível avaliar a eficiência dos tratamentos propostos para o reparo ósseo, por não apresentarem diferenças significativas entre os grupos.Mononuclear cells from bone marrow have been used in various treatments of diseases in an attempt to regenerate tissues. The objective of this study was to evaluate the accession and proliferation of mononuclear cells in a critical defect, with the addition of platelet-rich plasma (PRP) and / or TGF-β1 (transforming growth factor beta 1), and then to evaluate bone repair at defective sites on the femurs of rats. We created a critical defect on the bilateral femurs of 33 Wistar-Kyoto rats. Mononuclear bone marrow cells, TGF-β and PRP were added to the lesion on the treated side and saline on the contralateral side. We determined the adhesion of mononuclear cells at the critical defect and bone repair. The presence and consequent adhesion of the mononuclear cells administered to the treated animals was not demonstrated by PCR. Radiographic analysis showed closure of the lesion, but we could not affirm that this resulted from the treatments administered or by normal bone regeneration itself, when the lesion was evaluated at 6 and 10 weeks postoperative, seeing that there were no significant differences between the groups. Conclusions: a)Bone marrow mononuclear cells did not adhere at the critical defect created in the rat femur; b) It was not possible to determine the efficiency of the bone repair treatments studied, as the results did not show significant differences between the groups

Naringin supplementation during pregnancy induces sex and region-specific alterations in the offspring’s brain redox status

Research has shown the beneficial effects of naringin supplementation to adult rodents, which can ameliorate oxidative stress in disease models. However, evidence has demonstrated that polyphenol supplementation induced detrimental effects when consumed during sensitive periods of development, such as pregnancy. Therefore, we investigated the effect of maternal naringin supplementation during pregnancy on the offspring’s cerebral redox status. Pregnant Wistar rats were divided into control and naringin groups and supplemented from gestational day 15 to gestational day 21. On postnatal days 1, 7, and 21, offspring were euthanized, and the prefrontal cortex, hippocampus, striatum, and cerebellum dissected. On postnatal day 1, maternal naringin supplementation positively modulated the pups’ brain redox status. On postnatal day 7, a pro-oxidative milieu was observed in the offspring’s striatum and cerebellum in a sex-dependent manner, even though the prefrontal cortex and hippocampus were not negatively affected. Besides, the alterations observed on postnatal day 7 did not persist up to weaning. Our findings demonstrated that the effect induced by naringin supplementation in the brain redox status differed according to the period of development in which naringin was consumed since the beneficial effects usually found in the adult rodents became detrimental when the supplementation was applied during pregnancy

Supplementation with green tea and oregano extracts on productive characteristics, blood metabolites, and antioxidant status of Jersey cows during the transition period

Plant extracts have been recognized as beneficial to human health and have been evaluated as feed additive for domestic and companion animals. This study evaluated oregano and green tea extracts fed to Jersey cows from approximately 21 d before calving to 21 d after calving on milk production, milk composition, and blood metabolites as well as investigated immunological and antioxidant attributes. Twenty-four Jersey cows with 441±27 kg of BW, 3.5±0.3 of body condition score (BCS), and 2.7±1.8 lactations were selected at approximately 28d before the expected parturition date and were randomly assigned to three treatments with eight cows each: without plant extracts in diet (control – CON), addition of 10g per day of oregano extract (OR), and addition of 5g per day of green tea extract (GT). Feed intake, BW, BCS, blood metabolites, hemogram as well as oxidative stress biomarkers were evaluated from approximately 3 weeks prepartum to 3 weeks postpartum (transition period) while milk production and composition were evaluated during the first 3 weeks of lactation. Plant extracts did not change BW, BCS, and DM intake (DMI) throughout the transition period, but OR increased in approximately 20% total digestive nutrients and metabolizable energy intake on days 15 and 16 postpartum compared with CON. In the prepartum, OR increased in 48% platelets count compared to the CON, while GT augmented in 142% eosinophils compared with CON. Oregano extract reduced the levels of reactive species in the erythrocytes in 40% during prepartum and postpartum compared with CON, while GT reduced its levels in 24 and 29% during prepartum and postpartum, respectively, when compared with CON. In the postpartum period, OR increased in 60% the carbonylated protein content compared with CON, while GT reduced in 45% the levels of reactive species in plasma compared with CON. During the postpartum, both extracts increased in 33% the concentration of reduced glutathione when compared with CON. Moreover, GT tended to decrease feed efficiency in 11% when compared with CON; OE reduced milk pH and somatic cell count when compared with CON. In conclusion, OE and GT did not expressively affect immunological attributes in blood but reduce some oxidative stress biomarkers without compromising productive traits of Jersey cows during the transition period

Physical Exercise During Pregnancy Prevents Cognitive Impairment Induced by Amyloid-ß in Adult Offspring Rats

Alzheimer’s disease (AD) is the main aging-associated neurodegenerative disorder and is characterized by mitochondrial dysfunction, oxidative stress, synaptic failure, and cognitive decline. It has been a challenge to find disease course-modifying treatments. However, several studies demonstrated that regular physical activity and exercise are capable of promoting brain health by improving the cognitive function. Maternal lifestyle, including regular exercise during pregnancy, has also been shown to influence fetal development and disease susceptibility in adulthood through fetal metabolism programming. Here, we investigated the potential neuroprotective role of regular maternal swimming, before and during pregnancy, against amyloid-β neurotoxicity in the adult offspring. Behavioral and neurochemical analyses were performed 14 days after male offspring received a single, bilateral, intracerebroventricular (icv) injection of amyloid-β oligomers (AβOs). AβOs-injected rats of the sedentary maternal group exhibited learning and memory deficits, along with reduced synaptophysin, brain-derived neurotrophic factor (BDNF) levels, and alterations of mitochondrial function. Strikingly, the offspring of the sedentary maternal group had AβOs-induced behavioral alterations that were prevented by maternal exercise. This effect was accompanied by preventing the alteration of synaptophysin levels in the offspring of exercised dams. Additionally, offspring of the maternal exercise group exhibited an augmentation of functional mitochondria, as indicated by increases in mitochondrial mass and membrane potential, α-ketoglutarate dehydrogenase, and cytochrome c oxidase enzymes activities. Moreover, maternal exercise during pregnancy induced long-lasting modulation of fusion and fission proteins, Mfn1 and Drp1, respectively. Overall, our data demonstrates a potential protective effect of exercise during pregnancy against AβOs-induced neurotoxicity in the adult offspring brain, by mitigating the neurodegenerative process triggered by Alzheimer-associated AβOs through programming the brain metabolism.This study was supported by the Pró-Reitoria de Pesquisa/Universidade Federal do Rio Grande do Sul (PROPESQ/UFRGS). CPK is a PhD Postgraduate student in Biological Sciences – Biochemistry receiving grants from the Brazilian agency Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). CM received grants from CNPq (Universal 442406/2014-2 and INCT 465671/2014-4)

Plant extracts supplied to pre-weaned dairy calves influence their redox status

This study aimed to evaluate the effects of the separate provision of green and oregano tea extracts on the biomarkers of the redox state and health condition in pre-weaned Jersey calves from birth to 60 days of life. Two experiments following the complete randomized design with measures repeated in time were carried out using 38 Jersey calves (17 and 21 calves in experiments 1 and 2, respectively). Calves were distributed according to date of birth into one of three groups: control (CON) - with no addition of extracts; oregano extract (OE) - addition of 70 mg of oregano extract/kg of body weight (BW) and green tea extract (GT) - addition of 35 mg of green tea extract/kg of BW. Eight biomarkers of the redox state were evaluated on days 1, 30, and 60 after birth, and variables measured on day 1 were used as covariates. Body temperature and occurrence of diarrhea were evaluated every two days. Regarding the main results, the supply of oregano extract reduced the concentration of oxidizing biomarkers, such as DCFP (oxidation of dichlorofluorescein in plasma) and carbonyl, and increased the activity of antioxidant enzymes, such as GPx and catalase. Green tea extract only reduced DCFP and tended to improve catalase activity. Calves remained healthy (no fever and only a few days with diarrhea), and plant extracts did not improve their health condition. The addition of green tea and oregano extracts into the diet has a positive effect on redox status in pre-weaned Jersey calves

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Atividade de mediadores lip?dicos derivados de ?cidos graxos poli-insaturados sobre altera??es comportamentais e bioqu?micas em um modelo de fibromialgia em camundongos

Made available in DSpace on 2015-04-14T14:51:31Z (GMT). No. of bitstreams: 1 457610.pdf: 991749 bytes, checksum: d91843d27688e0357561bae1a127e7a1 (MD5) Previous issue date: 2014-02-28This study investigated whether the spinal or systemic treatment with the lipid resolution mediators resolvin D1 (RvD1), aspirin-triggered resolvin D1 (AT-RvD1) and resolvin D2 (RvD2) might interfere with behavioral and neurochemical changes in the mouse fibromyalgia-like model induced by reserpine. Acute administration of AT-RvD1 and RvD2 produced a significant inhibition of mechanical allodynia and thermal sensitization in reserpine-treated mice, whereas RvD1 was devoid of effects. A similar antinociceptive effect was obtained by acutely treating animals with the reference drug pregabalin. Noteworthy, the repeated administration of AT-RvD1 and RvD2 also prevented the depressive-like behavior in reserpine-treated animals, according to assessment of immobility time, although the chronic administration of pregabalin failed to affect this parameter. The induction of fibromyalgia by reserpine triggered a marked decrease of dopamine and serotonin (5-HT) levels, as examined in total brain, spinal cord, cortex and thalamus. Reserpine also elicited a reduction of glutamate levels in total brain, and a significant increase in the spinal cord and thalamus. Chronic treatment with RvD2 prevented 5-HT reduction in total brain, and reversed the glutamate increases in total brain and spinal cord. Otherwise, AT-RvD1 led to a recovery of dopamine levels in cortex, and 5-HT in thalamus, whilst it diminished brain glutamate contents. Concerning pregabalin, this drug prevented dopamine reduction in total brain, and inhibited glutamate increase in brain and spinal cord of reserpine-treated animals. Our data provide novel evidence, showing the ability of D-series resolvins AT-RvD1, and mainly RvD2, in reducing painful and depressive symptoms allied to fibromyalgia in mice.O presente estudo investigou o poss?vel efeito do tratamento central ou sist?mico com os mediadores lip?dicos de resolu??o da inflama??o, Resolvina D1 (RvD1), RvD1 ativada pela aspirina (AT-RvD1) e Resolvina D2 (RvD2) sobre mudan?as comportamentais e neuroqu?micas em um model de fibromialgia induzido por reserpina em camundongos. A administra??o aguda de AT-RvD1 e RvD2 produziu um efeito inibit?rio significativo sobre a alod?nia mec?nica e a hipersensibiliza??o t?rmica nos animais tratados com reserpina, sendo que nenhum efeito foi observado quando os animais foram tratados com RvD1. A administra??o aguda de pregabalina, f?rmaco de refer?ncia para o tratamento da fibromialgia, apresentou um efeito antinociceptivo similar ?quele observado para AT-RvD1 e RvD2. Interessante, a administra??o repetida e sist?mica de AT-RvD1 e RvD2 tamb?m preveniu o comportamento depressivo nos animais que receberam reserpina, de acordo com a avalia??o do tempo de imobilidade, enquanto que a administra??o cr?nica de pregabalina n?o apresentou efeito sobre esse par?metro. A indu??o de fibromialgia pela reserpina produziu uma redu??o marcante dos n?veis de dopamina e serotonina (5-HT), quando avaliados no c?rebro total, medula espinhal, c?rtex e t?lamo. A reserpina tamb?m promoveu uma redu??o nos n?veis de glutamato no c?rebro total e, um aumento significativo na medula espinhal e no t?lamo. O tratamento cr?nico com RvD2 preveniu a redu??o de 5-HT no c?rebro total e, reverteu o aumento do glutamato no c?rebro total e medula espinhal. Por outro lado, AT-RvD1 restaurou os n?veis de dopamina no c?rtex e de 5-HT no t?lamo, ao mesmo tempo em que, reduziu os n?veis de glutamato no c?rebro. Em rela??o ? pregabalina, ela preveniu a redu??o de dopamina no c?rebro total e inibiu o aumento do glutamato no c?rebro e na medula espinhal dos animais tratados com reserpina. Nossos resultados fornecem novas evid?ncias quanto aos efeitos da AT-RvD1 e, principalmente RvD2 na redu??o da dor e, ainda, da depress?o, no modelo de fibromialgia induzida por em camundongos