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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Vliv inhibice SIRT1 na morfologii a chování Dánia pruhovaného / The impact of SIRT1 inhibition on zebrafish morphology and behavior

Faustová, Zuzana January 2013 (has links)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Zuzana Faustová Supervisor: Prof. Doutor Jorge Miguel de Ascenção Oliveira PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: The impact of SIRT1 inhibition on zebrafish morphology and behavior After discovery of connection between yeast Silent Information Regulator 2 (Sir2) and its ability to alter lifespan, Sir2 and its seven mammalian orthologs became very attractive therapeutic target. These so called sirtuins are members of a histone deacetylase family. They possess unique catalytic activity having nicotinamide adenine dinucleotide as a cofactor and their function can be influenced by environmental factors. The aim of this diploma thesis was to extend knowledge of Sirtuin 1 (SIRT1), which is from all mammalian sirtuins considered to have the closest relation to yeast Sir2. At first we tested the impact of SIRT1 inhibition on early developmental stages of zebrafish (Danio rerio) embryos and larvae, finding out that SIRT1 is important for normal development and SIRT1 inhibition or malfunction result in cardiovascular defects, delayed development, and death. Additionally, we tried to learn more about SIRT1 and its connection with Parkinson's disease by combining nontoxic doses...
32

Exploring the Relationship of the Expression of Phenotypic Plasticity of Organ Mass and Activity and Resource Allocation in Diploptera punctata

Reagan, Elizabeth M. January 2021 (has links)
No description available.
33

Mechanisms for the recovery of type 2 diabetes mellitus following bariatric surgery

Gamby, Danielle Nicole 12 March 2016 (has links)
Studies have shown that following bariatric surgery, there is an almost immediate reversal of type 2 diabetes. However, there still remains questions as to why this occurs and what possible explanations there may be. This paper aims to focus on several studies that have found a reversal of diabetes in obese patients who have undergone bariatric surgery. Furthermore, it explores several possibilities for the reasons behind this reversal including the role of AMP-activated protein kinase, the incretins gastric inhibitory peptide and glucagon-like peptide-1, and also looks at genetics. Bariatric surgery and a description of certain mechanisms are first described for an understanding. Following is a literature review of published studies on bariatric surgery, the reversal of diabetes following the procedure, and roles of AMPK and incretins. Because of the possibility that reduced caloric intake may not be the major factor in the diabetic reversal, it is suggested that further research be done on obese and normal weight patients and observe the levels of the mentioned mechanisms and also various genes to see if they offer a more thorough explanation.
34

Novel cambinol analogues as potential anticancer agents : an improved understanding of sirtuin isoform selectivity

Medda, Federico January 2011 (has links)
SIRT1 and SIRT2 are two NAD⁺-dependent deacetylases which negatively modulate the activity of p53, a protein which is involved in cell cycle arrest, senescence and apoptosis following genotoxic stress. Part I of the thesis describes the exploration of the chemical space around a reported unselective and modest inhibitor of SIRT1 and SIRT2 with the aim of improving the selectivity and potency of the inhibitor against the two isoforms. Particular emphasis is placed upon understanding the mode of binding of the novel analogues within the active site of the enzymes. Chapter 1 reviews the physiological roles of class III NAD⁺-dependent deacetylases, also known as sirtuins. In particular, the application of SIRT1 and SIRT2 inhibitors as potential anticancer agents is described. Amongst these, only cambinol and the tenovins showed in vivo activity in a mouse xenograft model. Previously only one analogue of cambinol had been reported in the literature. Chapter 2 describes the development of a small collection of novel cambinol analogues (First Generation Studies). The role played by different substituents at the phenyl group and at the N-1 of the thiouracil core is discussed. Along with the synthesis and structure activity relationship (SAR) associated with the core structure, in-cell experiments intended to confirm the activity of the most active compounds are reported. Chapter 3 provides a rationalisation for the SAR discussed in Chapter 2. Based on computational molecular modelling studies (GOLD), the activity of the most potent and selective SIRT2 inhibitors is explained. Two series of novel cambinol analogues were designed (Second and Third Generation Analogues) in order to assess further the proposed binding mode. Chapter 4 focuses on the development of the “Second Generation” analogues, characterised by the presence of lipophilic substituents at the sulfur atom and at the N-3 position of the thiouracil core. The synthesis, biological evaluation and SAR are discussed in detail. Chapter 5 reports the development of the “Third Generation” analogues, characterised by either a benzyl group or para-alkoxy-substituted benzyl group at the N-1 position of cambinol. Once again, the synthesis, biological evaluation and SAR data are presented. An improved understanding of the mode of binding of the novel compounds is proposed based on molecular dynamics (MD) studies. Indole-based alkaloids, such as Vincristine and Vinblastine, are well known for their anticancer activity. Recently, the anticancer activity of members of the calycanthaceous family of alkaloids has been discovered. Part II of the thesis focuses on model studies aimed at developing the total synthesis of one of these compounds, perophoramidine. Chapter 7 provides an overview of the calycanthaceous alkaloid family of natural products, including their biological properties. The structural features of perophoramidine, along with the previously reported synthetic studies are outlined. Chapter 8 describes the synthesis of an advanced intermediate in the total synthesis of dehaloperophoramidine, a structural analogue of perophoramidine Problems encountered, optimisation studies and the synthesis of a re-designed intermediate are also reported in this chapter.
35

Influência do tratamento da doença periodontal na sirtuína 1 e na lectina ligadora de manose em indivíduos com doença arterial coronária / Influence of treatment of periodontal disease on the sirtuin 1 system and mannose-binding lectin in individuals with coronary artery disease

Caribé, Pérola Michelle de Vasconcelos 24 January 2019 (has links)
INTRODUÇÃO: A premissa da relação entre o processo aterosclerótico da doença arterial coronária e a doença periodontal é o processo imunoinflamatório, que provoca aumento significativo da concentração sérica de lectina ligadora de manose. Essa proteína é parte da imunidade inata e possui a capacidade de ligar-se aos resíduos de manose comuns a vários patógenos. Estudos em animais também mostraram que o aumento da concentração sérica de sirtuína-1 associou-se com redução da inflamação. Evidências indicam que a sirtuína-1 desempenha um importante papel na proteção vascular e está associada ao envelhecimento. OBJETIVOS: Esse estudo analisou a influência do tratamento não cirúrgico da doença periodontal na concentração sérica de lectina ligadora de manose e de sirtuína-1 em pacientes com doença periodontal e doença arterial coronária. MÉTODOS: Foram avaliados 78 pacientes, 38 mulheres e 40 homens, média de idade de 58 ± 8 anos, distribuídos em 4 grupos: 20 indivíduos saudáveis (grupo 1), 18 pacientes com doença aterosclerótica e isentos da doença periodontal (grupo 2), 20 pacientes com doença periodontal e isentos de doença arterial coronária (grupo 3) e 20 pacientes com doença aterosclerótica e doença periodontal (grupo 4). Foi realizada coleta de sangue periférico no início e no final do tratamento da doença periodontal. RESULTADOS: Observou-se uma correlação negativa entre a variação de concentração de lectina ligadora de manose e a concentração de sirtuína-1 (r = -0,30; p = 0,006). Os pacientes que receberam tratamento para a doença periodontal tiveram aumento da concentração sérica de sirtuína-1 (1,06 ± 1,03 vs. 1,66 ± 1,64 ng/mL; p < 0,001) e redução da concentração sérica da lectina ligadora de manose (1099,35 ± 916,59 vs. 861,42 ± 724,82 ng/mL; p < 0,001) quando comparamos os momentos inicial e final do estudo. Observou-se redução na concentração sérica da lectina ligadora de manose e aumento da sirtuína-1 nos grupos 3 e 4. A lectina ligadora de manose reduziu no grupo 3 de 886,27 ± 906,72 ng/mL para 689,94 ± 808,36 ng/mL (p = 0,003) e no grupo 4 de 1.312,43 ± 898,21 ng/mL para 1.032,90 ± 602,52 ng/mL (p = 0,010). A sirtuína-1 aumentou no grupo 3 de 0,80 ± 1,01 ng/mL para 1,49 ± 1,55 ng/mL (p = 0,005) e no grupo 4 de 1,32 ± 1,00 ng/mL para 1,82 ± 1,75 ng/mL (p = 0,044). CONCLUSÃO: O tratamento periodontal, além da redução de processos infecciosos locais, promove a redução da concentração sérica de lectina ligadora de manose e aumento da concentração sérica da sirtuína-1. Porém, estudos prospectivos serão necessários para avaliar o impacto das alterações séricas dessas proteínas como biomarcadores na incidência e no prognóstigo da doença arterial coronária / BACKGROUND: The premise of the relationship between the atherosclerotic process of coronary artery disease and periodontal disease is the immunoinflammatory process, which causes a significant increase in serum concentration of mannose-binding lectin. This protein is part of the innate immunity and has the ability to bind to the mannose residues common to various pathogens. Animal studies also showed that increased serum concentration of sirtuin-1 was associated with reduced inflammation. Evidence indicates that sirtuin-1 plays an important role in vascular protection and is associated with aging. OBJECTIVES: This study examined the influence of nonsurgical treatment of periodontal disease on the serum concentration of mannose-binding lectin and sirtuin-1 in patients with periodontal disease and coronary artery disease. METHODS: Seventy-eight patients, 38 women and 40 men, mean age 58 ± 8 years old, were divided into 4 groups: 20 healthy subjects (group 1), 18 patients with coronary artery disease and without periodontal disease (group 2), 20 patients with periodontal disease and without coronary artery disease (group 3) and 20 patients with coronary artery disease and periodontal disease (group 4). Peripheral blood samples were collected at the beginning and at the end of the treatment of periodontal disease. RESULTS: A negative correlation was observed between the concentration of mannose-binding lectin and the concentration of sirtuin-1 (r = -0.30; p = 0.006). Patients receiving treatment for periodontal disease had increased serum sirtuin-1 concentration (1.06 ± 1.03 vs. 1.66 ± 1.64 ng/mL, p < 0.001) and decreased serum mannose-binding lectin concentration (1099.35 ± 916.59 vs. 861.42 ± 724.82 ng/mL, p <0.001) when we compared the initial and final moments of the study. Reduction in serum concentration of mannose-binding lectin and increase of sirtuin-1 were observed in groups 3 and 4. Mannosebinding lectin reduced in group 3 from 886.27 ± 906.72 ng/mL to 689.94 ± 808 (P = 0.010), and in group 4 from 1312.43 ± 898.21 ng / mL to 1032.90 ± 602.52 ng/mL (p = 0.010). Sirtuin-1 increased in group 3 from 0.80 ± 1.01 ng/mL to 1.49 ± 1.55 ng/mL (p = 0.005) and in group 4 of 1.32 ± 1.00 ng/mL to 1.82 ± 1.75 ng/mL (p = 0.044). CONCLUSION: The periodontal treatment, in addition to the reduction of local infectious processes, promoted the reduction of serum concentration of mannose-binding lectin and increased serum concentration of sirtuin-1. However, prospective studies will be needed to evaluate the impact of serum changes of these proteins as biomarkers on the incidence and prognosis of coronary artery disease
36

Avaliação morfofuncional e expressão gênica de Sirt1 no pulmão de camundongos jovens e idosos expostos ao particulado da exaustão de diesel (DEP) / Morphofunctional evaluation and Sirt1 gene expression in the lungs of young and old mice exposed to diesel exhaust particulate (DEP)

Ribeiro Júnior, Gabriel 16 February 2017 (has links)
A deterioração da qualidade do ar ameaça a qualidade de vida dos habitantes nos grandes centros urbanos. O material particulado é constituído por partículas sólidas, liquidas ou ambas, suspensas no ar. Os idosos são o grupo mais susceptível aos efeitos negativos da poluição atmosférica e essa população vem crescendo exponencialmente no mundo inteiro, afetando quase todos os países do mundo, inclusive o Brasil, atualmente representado por um contingente populacional correspondente a 12% da população. Há fortes evidências científicas que a família das sirtuínas tem grande influência no processo do envelhecimento e longevidade em mamíferos. Alguns estudos apontam uma função protetora de Sirt1 contra danos oxidativos e inflamatórios. O objetivo desse estudo é avaliar o impacto das partículas de exaustão do diesel (DEP) sobre as alterações pulmonares decorrentes do processo do envelhecimento e a possível influência das sirtuínas nesse processo. Camundongos na idade de 02 meses e 15 meses foram expostos às DEPs ou ar filtrado por um período de 30 dias. Os parâmetros funcionais foram mensurados pelo FlexiVent. Após as exposições os pulmões foram coletados e o perfil inflamatório avaliado no lavado broncoalveolar e no soro sanguíneo, por meio das mensurações das citocinas inflamatórias. O estresse oxidativo foi avaliado pela técnica espectrofotometria e as expressões gênicas das sirtuínas foram mensuradas pela técnica de RT-PCR no homogenato do tecido pulmonar. De forma geral, além das diferenças fisiológicas relacionadas com a idade observadas entre os grupos, às exposições as DEPs afetaram o perfil inflamatório e as enzimas antioxidantes nos animais jovens e idosos. Além disso, o grupo idoso apresentou comprometeram no ganho de peso e aumento na deposição de colágeno no tecido pulmonar. As exposições diminuíram os níveis de expressão gênica de Sirt6, enquanto Sirt1 foi diminuída com a idade. Em conjunto, os dados obtidos enfatizam que as exposições ambientais aceleraram as alterações associadas ao envelhecimento pulmonar / The deterioration of the air quality is a threat to the habitants\' quality of life of the urban areas. The particulate matter is constituted of solid, liquid or both particles suspended in the air. The elderly is the most susceptible group to the harmful effects of the air pollution and this population is growing exponentially all over the world, affecting almost all the countries, including Brazil, representing 12.1% of the population. There are strong scientific evidences that the Sirtuins family has great influence on the aging and longevity process in mammals. Some studies points out a Sirt1 protective function against oxidative and inflammatory damage. This study aims to evaluate the impact of the diesel exhaust particulate (DEP) on the pulmonary changes resulting from the aging process and the possible influence of the sirtuins in this process. Two and fifteen months old mice were exposed to DEP for a period of 30 days. Functional assessment of these animals was measured by FlexiVent. After the exposures period, the lungs were collected and the inflammatory profile was evaluated in the bronchoalveolar lavage fluid and blood serum, by means of the measurements of the inflammatory cytokines. Oxidative stress was evaluated by the spectrophotometric technique and the sirtuin gene expression was measured by the RT-PCR technique in the pulmonary tissue homogenate. Our data showed that, besides the age-related physiological differences observed between groups; exposure to DEPs affected the inflammatory profile and antioxidant enzymes activity in young and old animals. In addition, the elderly group presented compromised in weight gain and increased collagen deposition in lung tissue. The exposures decreased gene expression levels of Sirt6, while Sirt1 was decreased due to age. Taken together, the data obtained emphasize that environmental exposures accelerated changes associated with pulmonary aging
37

Estudi de l’expressió i funció del gen SIRT3 en el teixit adipós marró

Giralt Coll, Albert 14 October 2011 (has links)
SIRT3, membre de la família d’histona desacetilases anomenades sirtuïnes, es troba principalment al mitocondri de teixits amb alta capacitat oxidativa com el fetge, el múscul, el cor o teixit adipós marró i s’ha suggerit que podria jugar un paper en el metabolisme energètic. Per tal d’aclarir el seu rol en la termogènesi, es van analitzar les alteracions en ratolins SIRT3 -/- en dues condicions de termogènesi augmentada: la transició fetal-neonatal i l’exposició crònica al fred en ratolins adults, així com es va estudiar l’efecte del dejuni en adults SIRT3 -/- , una situació en la qual la termogènesi es troba inhibida. Es van avaluar els possibles trastorns metabòlics i es va procedir a un anàlisi transcriptòmic de l’expressió de gens marcadors de diverses vies metabòliques en el teixit adipós marró i altres teixits dels ratolins SIRT3 -/-. Els resultats obtinguts indiquen alteracions significatives en el període perinatal com a conseqüència de la manca de SIRT3, però no en l’etapa adulta. Concretament s’observa una expressió alterada de gens específics de la termogènesi (uncoupling protein-1, 5’-deiodinasa, PRDM16) al teixit adipós marró en l’etapa perinatal així com de gens implicats en l’oxidació d’àcids grassos (enoil-CoA, hidratasa/3-hidroxiacil CoA deshidrogenasa, acil-CoA oxidasa) al fetge durant l’etapa perinatal. Aquests resultats posen de manifest el potencial paper de SIRT3 en aquestes vies metabòliques i evidencien l’existència de mecanismes homeostàtics durant el desenvolupament post-natal capaços de compensar l’absència de SIRT3 en l’animal adult. D’altra banda, mitjançant l’ús d’adipòcits SIRT3 -/-, vam determinat que SIRT3 és necessària per una resposta apropiada de les cèl•lules a l’activació noradrenèrgica mediada per AMPc de l’expressió de gens termogènics del teixit adipós marró. El co-activador transcripcional PGC1α (peroxisome proliferator-activated receptor-γ coactivator-1α) indueix l’expressió de SIRT3 en adipòcits blancs i fibroblasts embrionaris com a part de la inducció global del patró d’expressió gènica específic del teixit adipós marró. A les cèl•lules sense SIRT3, PGC1α no pot induir completament l’expressió de gens termogènics específics de l’adipòcit marró. PGC1α activa la transcripció del gen SIRT3 a través de la coactivació del receptor nuclear orfe ERRα (estrogen-related receptor-α) el qual s’uneix a la regió proximal del promotor del gen SIRT3. Assajos de pèrdua de funció d’ERRα, indiquen que aquest és necessari per a la completa inducció de la l’expressió del gen SIRT3 en resposta a PGC1α. Aquests resultats indiquen que PGC1α controla l’expressió de SIRT3 i que aquesta acció és un component essencial del mecanisme global a través del qual PGC1α indueix la completa adquisició del fenotip d’adipòcit marró diferenciat. / SIRT3 is a member of the sirtuin family of deacetylases present mainly in mitochondria from tissues such as brown adipose tissue, liver, muscle and heart. To gain insight in the role of SIRT3 in thermogenesis, we determined the alterations in mice with targeted invalidation of the SIRT3 gene (SIRT3-/- mice) in two conditions of enhanced thermogenesis: the fetal-to-neonatal transition and chronic exposure of adult mice to cold, an in fasting of adult mice, a condition of depressed thermogenesis. Assessment of overall metabolic disturbances and a transcritomic analysis of the expression of marker genes of distinct metabolic pathways were performed in brown fat and other tissues from SIRT3-/- mice in these conditions. Results indicated significant alterations in the perinatal period but not in adulthood. Impaired expression of specific genes of thermogenesis in perinatal brown fat, and of genes encoding components of the fatty acid oxidation machinery in perinatal liver were observed in SIRT3-/- mice. Results highlight the potential role of SIRT3 in these pathways and evidence the appearance of homeostatic mechanisms during post-natal development capable to compensate for the absence of SIRT3 in the adulthood. Sirt3 is expressed in association with brown adipocyte differentiation. Using Sirt3-null brown adipocytes, we determined that Sirt3 is required for an appropriate responsiveness of cells to noradrenergic, cAMP-mediated activation of the expression of brown adipose tissue thermogenic genes. The transcriptional coactivator Pgc-1α (peroxisome proliferator-activated receptor-γ coactivator-1 α) induced Sirt3 gene expression in white adipocytes and embryonic fibroblasts as part of its overall induction of a brown adipose tissue-specific pattern of gene expression. In cells lacking Sirt3, Pgc-1α failed to fully induce the expression of brown fat-specific thermogenic genes. Pgc-1α activates Sirt3 gene transcription through coactivation of the orphan nuclear receptor Err (estrogen-related receptor)- α, which bound the proximal Sirt3 gene promoter region. Errα knockdown assays indicated that Errα is required for full induction of Sirt3 gene expression in response to Pgc-1 α. The present study indicates that Pgc-1α controls Sirt3 gene expression and this action is an essential component of the overall mechanisms by which Pgc-1α induces the full acquisition of a brown adipocyte differentiated phenotype.
38

Efectes de l'exercici físic en l'envelliment: Implicació de la via de sirtuïna 1, el procés d'autofàgia i la via WNT en rata

Bayod Gimeno, Sergi 18 June 2013 (has links)
Un estil de vida saludable, on la pràctica d’exercici físic hi és present, millora diferents aspectes relacionats amb el deteriorament cognitiu i fisiològic associat a l’envelliment. Malgrat que els estudis en rosegadors confirmen aquests beneficis, els mecanismes moleculars implicats tant a nivell cerebral com a nivell perifèric no estan del tot ben establerts. Per aquest motiu en aquesta tesi doctoral s’ha volgut avaluar tant a nivell cerebral (hipocamp i còrtex cerebral) com a nivell perifèric (múscul esquelètic, fetge i cor) en rates mascle Sprague-Dawley als 10 mesos de vida (rates adultes) el procés d’envelliment sobre algunes de les vies moleculars que s’han relacionat i resulten alterades amb l’edat, com són la via de sirtuïna 1, el procés d’autofàgia i la via Wnt (via canònica). D’altra banda, s’ha volgut determinar la possible modulació de les anteriors vies amb la realització d’exercici físic moderat de llarg termini (dut a terme durant 36 setmanes des de les 5 setmanes de vida, 4-5 dies a la setmana, durant 30 minuts al dia). Els resultats obtinguts a nivell cerebral mostren com l’exercici físic és capaç d’activar la via de sirtuïna 1 (via de supervivència cel•lular) i la biogènesi mitocondrial, el que contribuiria tot plegat al manteniment de la supervivència, la funcionalitat i l’estructura neuronal. També l’exercici, al disminuir els nivells de tau fosforilada a més d’augmentar els nivells de sinaptofisina, estaria implicat en el manteniment de la transmissió sinàptica. D’altra banda, l’activació tant del procés d’autofàgia a nivell del còrtex cerebral com de la via de la Wnt a nivell de l’hipocamp, contribuiria al manteniment de l’homeòstasi i supervivència neuronal. Cal destacar la implicació de sirtuïna 1 en l’activació tant del procés d’autofàgia com de la via Wnt. Així, amb els nostres resultats podem considerar a sirtuïna 1 com un dels elements clau en la regulació de les diferents vies moleculars i processos estudiats en aquesta tesi doctoral, i que la pràctica d’exercici moderat de llarg termini és capaç de modular. Pel que fa als resultats obtinguts a nivell perifèric (múscul esquelètic, fetge i cor), també es va determinar una activació de la via de sirtuïna 1 amb l’exercici en tots els teixits. En canvi, l’estimulació de la biogènesi mitocondrial tan sols es va produir a nivell muscular. També l’exercici va augmentar els nivells proteics dels enzims SOD i CAT en el múscul, revertint així l’augment del dany oxidatiu de proteïnes i lípids amb l’edat a nivell muscular (també en el fetge l’exercici va disminuir el dany oxidatiu de proteïnes), contribuint així tot plegat a la millora funcional a nivell perifèric. L’exercici físic també va incrementar els nivells de VEGF en fetge i cor, fet que podria estimular l’angiogènesi en aquests òrgans. I pel que fa al mecanisme d’autofàgia, solament es van observar alguns canvis destacats a nivell hepàtic, els quals podrien estar relacionats amb la disminució del contingut lipídic en aquest òrgan. Com a conclusió que se’n deriva d’aquesta tesi doctoral és que la realització d’exercici físic des que un és jove, sinònim d’un estil de vida saludable, podria ser una bona estratègia terapèutica amb l’objectiu de prevenir i/o retardar el deteriorament cognitiu i fisiològic que es produeix amb l’envelliment, el qual conduiria al desenvolupament de les malalties neurodegeneratives i metabòliques, ambdues molt presents actualment en la societat actual dels països desenvolupats. / Exercise is known to have beneficial effects on the organism and is increasingly recognized as determinant of successful aging. However, the molecular and cellular mechanisms underlying these effects remain to be elucidated. For this reason, we studied the effects of the aging process on the sirtuin 1 pathway, the autophagy (macroautophagy) and the canonical Wnt pathway, all of which related with the aging process, in adult male Sprague-Dawley rats (10 months), both in the brain (hippocampus and cortex) and peripheral tissues (skeletal muscle, liver and heart). Moreover, we examined the effects of long-term moderate treadmill exercise (30 min, 4-5 days per week for 36 weeks from 5 weeks) on the above pathways. At cerebral level, our results showed a sirtuin 1 pathway activation and an increase in mitochondrial biogenesis induced by exercise. In addition, exercise increased synaptophysin levels and reduced both levels of phospho-tau and GSK3β activation. On the other hand, exercise induced the macroautophagy in the cortex and Wnt signaling pathway in the hippocampus. Thus, in our rodent model, long-term moderate exercise leads to neuroprotection trough the upregulation of several pathways related with homeostasis and neuronal survival, and also the prevention of signs of neurodegeneration. It is noteworthy to consider the important role of sirtuin 1 modulating the different pathways studied. In peripheral tissues, long-term moderate exercise induced the sirtuin 1 pathway activation in all rat tissues studied, but only increased mitochondrial biogenesis in the muscle. On the other hand, SOD and CAT protein levels were increased by exercise in the muscle, together with a reduction of oxidative damage of lipids and proteins (the latter also reduced in liver with exercise). Increased VEGF protein levels were found in the liver and the heart, which could induce the angiogenic process in these organs. As for macroautophagic process, only important changes were observed in liver, which could be related with metabolic effects, reducing lipid content. Therefore, these results support that exercise also contributes to functional improvement in peripheral tissues. To conclude, our results show several benefits related to long-term moderate exercise from young ages on different pathways and parameters related with aging, which reinforce the beneficial role of exercise to prevent or delay the age-related cognitive and physiological impairments.
39

Avaliação morfofuncional e expressão gênica de Sirt1 no pulmão de camundongos jovens e idosos expostos ao particulado da exaustão de diesel (DEP) / Morphofunctional evaluation and Sirt1 gene expression in the lungs of young and old mice exposed to diesel exhaust particulate (DEP)

Gabriel Ribeiro Júnior 16 February 2017 (has links)
A deterioração da qualidade do ar ameaça a qualidade de vida dos habitantes nos grandes centros urbanos. O material particulado é constituído por partículas sólidas, liquidas ou ambas, suspensas no ar. Os idosos são o grupo mais susceptível aos efeitos negativos da poluição atmosférica e essa população vem crescendo exponencialmente no mundo inteiro, afetando quase todos os países do mundo, inclusive o Brasil, atualmente representado por um contingente populacional correspondente a 12% da população. Há fortes evidências científicas que a família das sirtuínas tem grande influência no processo do envelhecimento e longevidade em mamíferos. Alguns estudos apontam uma função protetora de Sirt1 contra danos oxidativos e inflamatórios. O objetivo desse estudo é avaliar o impacto das partículas de exaustão do diesel (DEP) sobre as alterações pulmonares decorrentes do processo do envelhecimento e a possível influência das sirtuínas nesse processo. Camundongos na idade de 02 meses e 15 meses foram expostos às DEPs ou ar filtrado por um período de 30 dias. Os parâmetros funcionais foram mensurados pelo FlexiVent. Após as exposições os pulmões foram coletados e o perfil inflamatório avaliado no lavado broncoalveolar e no soro sanguíneo, por meio das mensurações das citocinas inflamatórias. O estresse oxidativo foi avaliado pela técnica espectrofotometria e as expressões gênicas das sirtuínas foram mensuradas pela técnica de RT-PCR no homogenato do tecido pulmonar. De forma geral, além das diferenças fisiológicas relacionadas com a idade observadas entre os grupos, às exposições as DEPs afetaram o perfil inflamatório e as enzimas antioxidantes nos animais jovens e idosos. Além disso, o grupo idoso apresentou comprometeram no ganho de peso e aumento na deposição de colágeno no tecido pulmonar. As exposições diminuíram os níveis de expressão gênica de Sirt6, enquanto Sirt1 foi diminuída com a idade. Em conjunto, os dados obtidos enfatizam que as exposições ambientais aceleraram as alterações associadas ao envelhecimento pulmonar / The deterioration of the air quality is a threat to the habitants\' quality of life of the urban areas. The particulate matter is constituted of solid, liquid or both particles suspended in the air. The elderly is the most susceptible group to the harmful effects of the air pollution and this population is growing exponentially all over the world, affecting almost all the countries, including Brazil, representing 12.1% of the population. There are strong scientific evidences that the Sirtuins family has great influence on the aging and longevity process in mammals. Some studies points out a Sirt1 protective function against oxidative and inflammatory damage. This study aims to evaluate the impact of the diesel exhaust particulate (DEP) on the pulmonary changes resulting from the aging process and the possible influence of the sirtuins in this process. Two and fifteen months old mice were exposed to DEP for a period of 30 days. Functional assessment of these animals was measured by FlexiVent. After the exposures period, the lungs were collected and the inflammatory profile was evaluated in the bronchoalveolar lavage fluid and blood serum, by means of the measurements of the inflammatory cytokines. Oxidative stress was evaluated by the spectrophotometric technique and the sirtuin gene expression was measured by the RT-PCR technique in the pulmonary tissue homogenate. Our data showed that, besides the age-related physiological differences observed between groups; exposure to DEPs affected the inflammatory profile and antioxidant enzymes activity in young and old animals. In addition, the elderly group presented compromised in weight gain and increased collagen deposition in lung tissue. The exposures decreased gene expression levels of Sirt6, while Sirt1 was decreased due to age. Taken together, the data obtained emphasize that environmental exposures accelerated changes associated with pulmonary aging
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Investigating the Regulation and Roles of Histone Acetylase and Deacetylase Enzymes for Cellular Proliferation and the Adenovirus Life Cycle

Robinson, Autumn Rose 29 July 2020 (has links)
No description available.

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