The author deals with oxidative stress and its effects on the pathogenesis of various diseases including the development of insulin resistance. The work is divided in the usual way overview of current knowledge on the issues, methods, results, discussion and conclusions. Part of this work is to describe an animal experiment in the waking state, whose introduction to our department was one of the tasks of this graduate work.

Charles University, Faculty of pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Lucie Ženklová Supervisors: Prof. Fabio Altieri and PharmDr. Ivan Vokřál, Ph.D. Title of diploma thesis: Involvement of PDIA3 in oxidative stress response PDIA3 is a member of the protein disulfide isomerase family (PDI) and it is a stress- responsive protein. It is also involved in various cellular signalling pathways and has various functions in the cell. The best-known location is in the endoplasmic reticulum where it plays a major role mainly in the proper folding and quality control of glycoproteins, and participation in the assembly of the major histocompatibility complex class I. However, its existence has also been described in many other cell compartments, such as nucleus, mitochondria, cell surface or cytosol, where it interferes in various processes. While in some instances these roles need to be confirmed by further studies, a lot of observations confirmed its involvement in the signal transduction (for example releated with STAT protein) from the cell surface and the regulatory processes in the nucleus. Recent studies have also confirmed its increased expression in various pathological states. The aim of our work was to find out what is its role in the exposure of the MDA-MB 468...

Calorie restriction (CR) is one of the few treatments that has been observed to significantly extend life in a wide variety of species. While its life-extending properties are still being investigated in primates, there is general agreement that it reduces oxidative stress and inflammation. Interestingly, there is some evidence that it may ameliorate or delay the onset of a number of neurodegenerative diseases, including age-related white matter degeneration. The processes underlying its neuroprotective effects in non-human primates are unknown, but oxidative stress and inflammation are potential contributors to age-related white matter pathologies that characterize aging in the monkey brain and correlate with cognitive decline. To determine if CR reduces damage due to oxidative stress and inflammation in the monkey brain, brains from four calorie restricted monkeys and four matched controls brains were processed for immunohistochemical analysis using an antibody against the pro-inflammatory protein S100b. S100b is a widely expressed calcium-binding cytoplasmic protein associated with neurological insults like ischemia, atrophy, and neurofibrillary tangles and plaques in Alzheimer's disease. It is primarily expressed in astrocytes, but is also expressed to a lesser extent in microglia, oligodendrocytes, and some neuronal populations. Stereology was used to estimate density of S100b labeling in the cingulum, corpus callosum and visual cortex. No significant difference between calorie restricted animals and controls was found. More specific markers of oxidative stress and inflammation may be more effective in revealing any significant differences between CR and control brains. Potential alternatives include antibodies against 4-hydroxynonenal, a lipid peroxidation product, and encephalitogenic peptides of myelin basic protein, which are only exposed to the extracellular environment when myelin is damaged.

Understanding how defense signaling pathways regulate neuronal protection in the compromised central nervous system (CNS) is essential for combating neurodegenerative disorders. This is apparent in the intrinsic activation of the transcription factor Nrf2 during periods of oxidative stress, a hallmark of neurodegeneration. This regulator of the antioxidant response induces the transcription of genes essential for protecting against oxidative stress-induced damage and is a prime target for drug discovery. Delayed-release dimethyl fumarate (DMF), currently approved for the treatment of relapsing-remitting forms of multiple sclerosis (MS), is believed to mediate its effect via the Nrf2 pathway; however, the exact mechanisms of action are unknown. The primary aim of the studies outlined in this dissertation was to identify the molecular mechanisms of Nrf2 regulation and subsequent cellular protection conferred by DMF and its bioactive metabolite, monomethyl fumarate (MMF). For this thesis study, transcriptional profiling studies following oral administration of DMF were conducted to characterize DMF pharmacodynamic responses in the central nervous system (CNS) and peripheral tissues to understand the functional effects of DMF in vivo as well as explore the necessity of Nrf2 in this process. Data from these studies confirm earlier findings that DMF activates transcription of Nrf2 target genes in the CNS and periphery; however, tissue-specific gene expression was also observed, indicating additional levels of transcriptional control beyond Nrf2 activation. These findings suggest that there may be unique cytoprotective and immunomodulatory capabilities of DMF within specific tissues. In the CNS, a novel Nrf2 transcriptional target gene OSGIN1 was identified to be significantly upregulated following DMF treatment in vivo; however, the contribution of this gene to the pharmacodynamic properties of DMF or MMF has not been previously described. Therefore, the in vitro effects of MMF on OSGIN1 expression were characterized, and the necessity of OSGIN1 in mediating cytoprotective effects against toxic oxidative stress in human astrocytes was evaluated. These data identify a potential mechanism for MMF-mediated cytoprotection in human astrocytes that function in an OSGIN1 and p53-dependent manner. Overall, the experiments described in this dissertation allow for a broader understanding of endogenous cellular protection and how it can be used to combat CNS disorders.

abstract: Birds have plasma glucose levels that are 1.5-2 times greater than mammals of similar body mass in addition to higher free fatty acid concentrations, both of which would typically impair endothelium-dependent vasodilation if observed in mammals. Endothelium-dependent vasodilation can be stimulated in mammals through the use of acetylcholine (ACh), which primarily acts through nitric oxide (NO) and cyclooxygenase (COX)-mediated pathways, with varying reliance on endothelial-derived hyperpolarizing factors (EDHFs). Very few studies have been conducted on small resistance systemic arteries from birds. The hypothesis was that because birds have naturally high glucose and free fatty acid concentrations, ACh-induced vasodilation of isolated arteries from mourning doves (Zenaida macroura) would be independent of endothelial-derived factors and resistant to high glucose-mediated vascular dysfunction. Small resistance mesenteric and cranial tibial (c. tibial) arteries were pre-constricted to 50% of resting inner diameter with phenyleprine then exposed to increasing doses of ACh (10-9 to 10-5 μM) or the NO donor, sodium nitroprusside (SNP; 10-12 to 10-3 μM). For both vessel beds, ACh-induced vasodilation occurred mainly through the activation of potassium channels, whereas vasodilation of mesenteric arteries additionally occurred through COX. Although arteries from both vessel beds fully dilated with exposure to sodium nitroprusside, ACh-mediated vasodilation was independent of NO. To examine the effect of high glucose on endothelium-dependent vasodilation, ACh dose response curves were conducted following exposure of isolated c. tibial arteries to either a control solution (20mM glucose) or high glucose (30mM). ACh-induced vasodilation was significantly impaired (p = 0.013) when exposed to high glucose, but normalized in subsequent vessels with pre-exposure to the superoxide dismutase mimetic tiron (10 mM). Superoxide concentrations were likewise significantly increased (p = 0.0072) following exposure to high glucose. These findings indicate that dove arteries do not appear to have endogenous mechanisms to counteract the deleterious effects of oxidative stress. Additional studies are required to assess whether endogenous mechanisms exist to protect avian vascular reactivity from systemic hyperglycemia. / Dissertation/Thesis / M.S. Nutrition 2012

Orientador: Marcelo Sady Plácido Ladeira / Banca: Luis Carlos Giarola / Banca: Alaor Aparecido Almeida / Banca: Aniele Radzikoski Agner / Banca: Rodrigo Otávio Alves de Lima / Resumo: É crescente o número de estudos que demonstram a importância de micronutrientes e compostos bioativos presentes nos alimentos na prevenção de diversas doenças degenerativas crônicas. Entretanto vários estudos moleculares epidemiológicos têm demonstrado que além de fatores ambientais, como a dieta, essas doenças degenerativas podem ser modulada por genes envolvidos no biometabolismo de xenobióticos, metabolismo do carbono e no reparo de DNA. Portanto, o presente estudo avaliou a possível influência do padrão alimentar e dos polimorfismos dos genes GSTP1, CYP1A1, XRCC1 e MTHFR sobre os níveis de danos oxidativos no DNA, uracilas incorporadas no DNA e eficiência do sistema de reparo de DNA em dois grupos de indivíduos residentes em Botucatu com diferentes padrões alimentares. Grupo I (GI): 87 indivíduos com alimentação rica em produtos orgânicos, grãos integrais, frutas e vegetais, e baixa ingestão de produtos industrializados; Grupo II (GII): 97 indivíduos com alimentação rica em produtos industrializados e pobres em frutas e vegetais. A quantificação do nível de danos oxidativos no DNA, uracilas incorporadas ao DNA e a eficiência do sistema reparo de DNA em linfócitos de sangue periférico, foi analisada utilizando-se o Teste do Ensaio Cometa. Os polimorfismos dos genes GSTP1, CYP1A1, XRCC1 e MTHFR foram analisados por realtime PCR. Também foi realizada a análise dos níveis de luteína, criptoxantina, -caroteno, -caroteno, licopeno, retinol e -tocoferol no plasma, pela técnica de cromatografia líquida de alta pressão (HPLC). Os indivíduos do GI apresentaram menores níveis de danos oxidativos no DNA e menores níveis de dano no DNA induzidos pela H2O2 quando comparados aos indivíduos do GII. Quanto aos subgrupos de micronutrientes: Indivíduos do subgrupo percentil 75 para todos os micronutrientes tiveram maior nível de danos no DNA do que os indivíduos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Not available / Doutor

Prions are infectious protein entities capable of self-replication. Prions are the causal agents behind the transmissible spongiform encephalopathies causing neurodegeneration and death in affected organisms. Prions have been identified in yeast with the best-characterized prions being [PSI+] and [PIN+], whose respective native proteins are the Sup35 translation termination factor and Rnq1 (function unknown). Autophagy is a cellular housekeeping mechanism mediating the degradation of damaged proteins and superfluous organelles. It is a highly sequential process regulated by autophagy related genes (ATGs). Autophagy has also been implicated in the clearance of amyloidogenic proteins including prions. However, the mechanistic basis underlying this activity is poorly understood, and a key objective of this project was to characterize how autophagy prevents spontaneous prion formation. Our study found that the deletion of core ATGs correlated with an increase in de novo [PSI+] and [PIN+] formation as well as Sup35 aggregation. Enhancement of autophagic flux through spermidine treatment attenuated the increased levels of de novo [PSI+] formation in mutants that normally show elevated levels of [PSI+] formation. Defective autophagy correlated with increased oxidatively damaged Sup35 in an atg1 mutant whereas anaerobic growth abrogated the increased [PSI+] formation in the atg1 mutant to wild-type levels. Our data suggest that autophagy serves a protective role in the clearance of oxidatively damaged Sup35 proteins that otherwise has a higher propensity towards [PSI+] prion formation. We also investigated the role of prion formation and autophagy during yeast chronological ageing which is the time that non-dividing cells remain viable. Prion diseases are associated with advanced age which correlates with a decline in cellular protective mechanisms including autophagy. Our study found an age dependent increase in the frequency of de novo [PSI+] formation with chronological age of yeast cells, more so in an atg1 mutant relative to the wild-type. Autophagy competent cells carrying the [PSI+] and [PIN+] prions also had improved chronological lifespan relative to prion free cells and atg1 cells. Cells carrying the [PSI+] prion elicited elevated autophagic flux that may promote improved lifespan thus suggesting a beneficial role of the [PSI+] prion during chronological ageing. The actin cytoskeleton provides the structural framework essential for a multitude of cellular processes to occur. We investigated the role of the Arp2/3 complex responsible for branching of actin filaments towards prion formation. Knockout mutants of the nucleation promoting factors of the Arp2/3 complex, in particular the abp1 mutant, showed reduced de novo [PSI+] formation and Sup35 aggregation under basal and oxidative stress conditions. Similarly, treatment with latrunclin A, an actin monomer-sequestering drug also abrogated de novo [PSI+] formation. Colocalization studies revealed that Sup35 often does not colocalize with Rnq1, a marker for the insoluble protein deposit (IPOD) in an abp1 mutant. This suggests a role for the Abp1 protein in the efficient transport of Sup35 molecules to the IPOD that may facilitate de novo [PSI+] prion formation under vegetative states and oxidant challenges.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第13852号 / 工博第2956号 / 新制||工||1436(附属図書館) / 26068 / UT51-2008-C768 / 京都大学大学院工学研究科合成・生物化学専攻 / (主査)教授 今中 忠行, 教授 青山 安宏, 教授 森 泰生 / 学位規則第4条第1項該当

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No. of bitstreams: 1 talita_emanuela_domingues.pdf: 1944980 bytes, checksum: c19178f686ffe12e73375417db38510c (MD5) Previous issue date: 2015 / A doen?a renal cr?nica consiste em les?o renal com perda progressiva e irrevers?vel da fun??o dos rins. Nesta fase, os pacientes recebem indica??o de terapia renal substitutiva sendo a Hemodi?lise o recurso mais utilizado. Evid?ncias indicam que a pr?tica de exerc?cio f?sico intradial?tico ? ben?fica. Entretanto, os benef?cios desta modalidade de exerc?cio sobre par?metros end?crino-metab?licos e de estresse oxidativo ainda s?o poucos conhecidos. Objetivo: Avaliar o efeito de uma sess?o de exerc?cio f?sico de intensidade leve a moderada, sobre par?metros end?crino-metab?licos e de estresse oxidativo de pacientes com doen?a renal cr?nica submetidos ? hemodi?lise. M?todos: Doze volunt?rios, alocados de forma randomizada, do Servi?o de Hemodi?lise da Santa Casa de Caridade de Diamantina/MG participaram do estudo. Todos foram cross-over durante o experimento, a fim de comparar os resultados entre os dias de hemodi?lise sem exerc?cio (HD s/ exc) e hemodi?lise com exerc?cio (HD c/exc), e os dias posterior ? sess?o de hemodi?lise sem exerc?cio (P-HD s/ exc) e posterior ? sess?o de hemodi?lise com exerc?cio (P-HD c/exc), para cada volunt?rio. O exerc?cio f?sico intradial?tico ocorreu de maneira supervisionada, e por meio de um cicloerg?metro port?til. A coleta de saliva para avalia??o dos par?metros end?crino-meteb?licos cortisol e testosterona ocorreu durante todos os dias do protocolo experimental, em seis momentos ao longo do dia, a saber: ao acordar (T1) e trinta minutos ap?s (T2), 12:00h (T3), 14:00h (T4), 16:00h (T5) e ?s 19h (T6). As amostras de sangue para avalia??o dos par?metros de estresse oxidativo foram coletadas apenas em dias de hemodi?lise, em dois momentos: antes (T3) e ap?s (T4) a sess?o de hemodi?lise. Resultados: As concentra??es de cortisol e testosterona para os dias de hemodi?lise com exerc?cio f?sico (HD c/exc) n?o se elevaram significativamente em rela??o ?s concentra??es apresentadas no dia de hemodi?lise sem exerc?cio f?sico (HD s/exc), o que tamb?m ocorreu para os dias posteriores ? aplica??o do protocolo de exerc?cio intradial?tico (PHD c/ exc e P-HD s/ exc). Entretanto, a raz?o testosterona/cortisol aumentou significativamente no dia posterior ? sess?o de hemodi?lise com exerc?cio (P-HD c/ exc) quando comparada ao dia posterior ? sess?o de hemodi?lise sem exerc?cio (P-HD s/ exc). Os par?metros de estresse oxidativo n?o apresentaram altera??es induzidas pelo protocolo de exerc?cio f?sico. Conclus?o: O exerc?cio f?sico intradial?tico alterou o status anab?lico 24 horas ap?s ? sua realiza??o e n?o induziu altera??es significativas nos par?metros de estresse oxidativo.sumo / Programa Multic?ntrico de P?s-gradua??o em Ci?ncias Fisiol?gicas, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2015. / Chronic kidney disease is a kidney injury with progressive and irreversible loss of kidney function. At the severe stage, patients undergo renal replacement therapy and the hemodialysis being the most used medical resource. Evidence indicates that the practical of physical exercise during the hemodialysis sessions is beneficial. However, the benefits of this exercise modality on endocrine-metabolic parameters and on oxidative stress remains unknown. Objective: To evaluate the effect of an exercise session mild to moderate intensity, on endocrine-metabolic parameters and oxidative stress in patients with chronic renal failure undergoing hemodialysis. Methods: Twelve users of the Hemodialysis Service of Santa Casa de Diamantina Charity / MG participated, were assigned randomly as volunteers in the study and were cross-over during all the experiment in order to compare the results between the days of hemodialysis session without exercise (HD s/ exc) and hemodialysis session with exercise (HD c/ exc), and the subsequent days of hemodialysis session without exercise (P-HD s/ exc) and after the hemodialysis session with exercise (P-HD w / exc) for each volunteer. The exercise protocol was performed in a portable bicycle ergometer and its intensity was previously determined for each volunteer as mild to moderate. Saliva samples were collected during all days of the experimental protocol, six times throughout the day, namely on waking (T1) and thirty minutes after (T2), 12: 00 (T3), 14 : 00 (T4), 16: 00h (T5) and 19h (T6) to determine the salivary cortisol concentrations and salivary testosterone concentrations. Blood samples were collected in days of hemodialysis sessions, in two times: pre (T3) and after (T4) hemodialysis session to determine the REDOX status parameters. Results: The concentrations of cortisol and testosterone on the days of hemodialysis with exercise (HD c / exc ) did not increase significantly in relation to the concentrations shown on hemodialysis day without exercise (HD s / exc ), which also happened after the exercise protocol application days (P-HD c/ exc and PHD s/exc). However, the reason testosterone/cortisol increased significantly on the day after the hemodialysis session with exercise (P-HD w / exc) when compared to the day after the hemodialysis session without exercise (P-HD s / exc). The oxidative stress parameters did not show induced changes by the physical exercise protocol. Conclusion: It was shown that the exercise protocol induced changes in the anabolic status 24 hours after its realization and did not induce changes in oxidative stress parameters.

Adipokinetic hormones (AKHs) are neuropeptides from the arthropod AKH/RPCH (adipokinetic hormone/ red pigment concentrating hormone) family. The typical AKH is an octa-, nona- or decamer that is synthesized, stored and released by the neurosecretory cells of the corpora cardiaca (CC) connected to the brain and primarily involved in the mobilization of energy reserves from the fat body in insects. In addition to its well established role in energy metabolism, AKH has also been implicated to be involved in stress responses specifically to oxidative stress. Oxidative stress induced elevation of AKH levels as well as a modulation of biomarkers of oxidative damage following exogenous application of AKH have been demonstrated. However, the discrete steps involved in the mode of action of AKH in triggering an anti-oxidative response is far from clear. Given the role of AKH as a neuroendocrine factor that mediates a response to oxidative stress, the mode of action of AKH at the sub-cellular level was investigated. Using isolated central nervous system (brain) as an in vitro model, we establish that AKH can potentiate an anti-oxidative response to oxidative stress. Further, we also demonstrate that AKH uses a conserved signal transduction mechanism involving both protein kinase C (PKC) and cyclic adenosine monophosphate (cAMP) and by mobilizing both intra as well as extra-cellular Ca2+ stores to elaborate its anti-oxidative response. Finally, using the genetically tractable fruit fly Drosophila melanogaster, we demonstrate through RNAi mediated knockdown of AKH synthesis as well as overexpression of AKH using the GAL4/UAS system, that the fork-head box transcription factor (dFoXO) might function downstream of AKH signaling in its stress responsive role. These results implicate AKH as a stress hormone while offering possibilities to further identify specific regulatory mechanisms and downstream effector molecules. Since stress signaling pathways are conserved, insights obtained from such studies on insects will offer some unique avenues for understanding stress responses and related pathologies in vertebrates including humans.