Chronic kidney disease (CKD) is growing global public health problem affecting 1 in 10 adults in developed countries and recognised as an important risk factor for cardiovascular disease (CVD) development. CVD is the main cause of death among CKD patients. Endothelial injury and dysfunction are critical steps in atherosclerosis, a major CVD. Oxidative stress (increased level of reactive oxygen species, ROS) has been associated with CVD development. Intravenous (IV) iron preparations are widely used in the management of CKD mediated anaemia, and have been associated with increased oxidative stress and cellular dysfunction. This study examined the effect of pharmacologically-relevant concentrations of IV Venofer (iron sucrose) or IV Ferinject (Ferric carboxymaltose, FCM) on primary human umbilical vein endothelial cell (HUVEC) activation/damage and on intracellular ROS generation as well as studying the potential mechanisms responsible. Data from TUNEL assay and Annexin V-FITC/PI staining showed that, IV FCM had no effect, but IV iron sucrose increased HUVEC apoptosis at 24hr. IV iron sucrose inhibited cell proliferation and reduced cell viability. Both compounds induced EC activation through sustained activation of p38 MAPK and up-regulation of ICAM-1 and VCAM-1. Additionally, the compounds induced significant increase in total ROS and superoxide anion production, which was attenuated by the anti-oxidant N-acetylcysteine (NAC). P38 MAPK showed up-regulation of pro-apoptotic protein Bax and down-regulation of antiapoptotic Bcl-2 protein in HUVEC treated with IV iron sucrose and p38 inhibition reversed these effects. In summary, these results suggest that IV iron sucrose causes more severe EC injury than IV FCM. However, both IV iron preparations induced intracellular ROS and superoxide anion generation in HUVEC leading to EC activation/dysfunction, providing a potential explanation for vascular damage in CKD patients.

Many organisms can acclimate to new environments through phenotypic plasticity, a complex trait that can be heritable, be subject to selection, and evolve. However, the rate and genetic basis of plasticity evolution remain largely unknown. Experimentally evolved populations of the nematode Caenorhabditis remanei were created by selecting for stress resistance under different environmental conditions. This resource was used to address key questions about how phenotypic plasticity evolves and what the genetic basis of plasticity is. Here, I highlight ways in which a fuller understanding of the environmental context influences our interpretation of the evolution of phenotypic plasticity. In a population selected to withstand heat stress, an apparent case of genetic assimilation did not show correlated changes in global gene regulation. However, further investigation revealed that the induced plasticity was not fixed across environments, but rather the threshold for the response was shifted over evolutionary time. Similarly, the past environment experienced by populations can play a role in directing the multivariate response to selection. Correlated responses to selection between traits and across environments were examined. The pattern of covariation in the evolutionary response among traits differed depending on the environment in which selection occurred, indicating that there exists variation in pleiotropy across the stress response network that is highly sensitive to the external environment. To understand how the patterns of pleiotropy are altered by environment and evolution, there is a pressing need to determine the structure of the molecular networks underlying plastic phenotypes. Using RNA-sequencing, the structure of the gene regulatory network is examined for a subset of evolved populations from one environment. Key modules within this network were identified that are strong candidates for the evolution of phenotypic plasticity in this system. Together, the data presented in this dissertation provide a comprehensive view of the myriad ways in which the environment shapes the genetic architecture of stress response phenotypes and directs the evolution of phenotypic plasticity. Additionally, the structure of transcriptional network provides valuable insight into the genetic basis of adaptation to environmental change and the evolution of phenotypic plasticity. This dissertation includes both previously published and co-authored material.

La presbyacousie est une perte de l'audition liée au vieillissement qui représente la troisième maladie chronique la plus répandue chez les personnes âgées. À ce jour, il est admis que le stress oxydant peut causer des dommages irréversibles à l'ADN et entraîner une sénescence prématurée dans les cellules en cycle. Cependant, il n'existe aucune donnée concernant le rôle des dommages de l'ADN dans la dégénérescence des cellules cochléaires liée à l’âge. En plus le lien entre le stress oxydant, les dommages à l'ADN et le vieillissement des cellules cochléaires demeure obscure.Le premier objet de ce travail était d'élucider le rôle des dommages de l'ADN dans la dégénérescence des cellules cochléaires. Pour ce faire, nous avons utilisé des approches de biologie moléculaire et cellulaire pour identifier des voies de signalisation associées aux lésions de l'ADN dans des explants cochléaires issus de souris âgées de 3 jours traitées au cisplatine (CDDP), molécule connue pour son effet secondaire ototoxique. De plus, nous avons étudié l'implication de p53, un des effecteurs clés de la signalisation des dommages de l'ADN, in vivo en traitant avec le CDDP des souris dont le gène codant pour ce facteur de transcription a été invalidé. Les possibilités de protéger l’audition contre l’effet nocif du CDDP ont été également étudiées en utilisant des inhibiteurs spécifiques ciblant les étapes clés des voies de signalisation. Enfin, nous avons utilisé des modèles murins porteurs de xénogreffes de cancer du sein humain afin de vérifier si les co-traitements permettaient de préserver l’audition sans compromettre l’efficacité anti-tumorale du CDDP. Nos résultats montrent que le CDDP induit des cassures doubles brins de l'ADN dans les cellules ciliées qui sont à l'origine de l'activation de la voie ATM-Chk2-p53 et, in fine, de la mort de ces cellules par apoptose. Nous avons également montré que l'absence de p53 in vivo prévient la perte de l'audition et la dégénérescence des cellules ciliées externes après injection intrapéritonéale de CDDP. L’application systémique ou locale de PFT-α, un inhibiteur de p53 prévient efficacement la perte auditive sans compromettre l’efficacité anti tumorale du CDDP.Le deuxième objectif de ma thèse a reposé sur l’identification des liens existant entre la surproduction des espèces réactives de l'oxygène (ROS), les dommages de l’ADN et l’apparition précoce des marqueurs de la sénescence cellulaire et de la perte de l’audition liée à l’âge. Pour ce faire, j’ai utilisé des explants cochléaires de souris âgées de 3 jours traitées au peroxyde hydrogène (H2O2). L’apparition des dommages à l’ADN et des cellules en sénescence a été étudiée en utilisant des techniques d’immunomarquage et de Western blot. Les résultats ainsi obtenus in vitro ont été ensuite validés in vivo sur les cochlées provenant de souris SAMP8 et de souris SAMR1. Afin de confirmer le rôle du stress oxydant dans l’apparition précoce de la presbyacousie, nous avons utilisé une lignée de souris invalidées pour le gène P66Shc, qui est un gène d'adaptation au stress connu pour ses rôles dans la surproduction de ROS et dans l’inhibition des enzymes antioxydants. Enfin, nous avons évalué la possibilité de prévenir ou de ralentir la perte de l’audition liée à l’âge en traitant les souris SAMP8 avec un mimétique de SOD/catalase, le EUK207. Nos résultats ont montré que: i) la surproduction de ROS est l'un des principaux facteurs causaux de la dégénérescence des cellules sensorielles de la cochlée liée à l’âge ; ii) L’activation de la voie p53-p21 entraînant l’apparition précoce de la sénescence dans les cellules cochléaires post-mitotiques, peut expliquer le vieillissement prématuré de la cochlée; iii) Le EUK207, un piégeur du superoxyde et du peroxyde d'hydrogène peut atténuer la ARHL chez les souris SAMP8. L’ensemble de ces résultats mettent en évidence des stratégies novatrices et efficaces pour la protection de l'audition. / Presbycusis or age-related hearing loss is the third most common chronic disease. It represents a major health issue in our modern society. This is due to its evolving feature and the invalidating character of this disease. To date, it is generally accepted that oxidative stress can cause irreversible DNA damage and lead to premature senescence in cycling cells. However, there is no data on the role of DNA damage in age-related cochlear cell degeneration. Moreover, the link between oxidative stress, DNA damage and cochlear cell aging remains unclear.The main objective of this work was therefore to elucidate the role of DNA damage in the degeneration of cochlear cells. To do this, we used molecular and cellular biology approaches to identify signaling pathways associated with DNA damage in cochlear explants from 3-days old mice treated with cisplatin (CDDP). This antineoplastic drug is cytotoxic by causing DNA damage and is known for its harmful effects on hearing. In addition, we investigated the involvement of p53, one of the key effectors of DNA damage signaling, in vivo by treating p53ko mice with cisplatin. Using specific inhibitors targeting key steps of signaling pathways, hearing protection from the harmful effect of CDDP have also been studied. Finally, we used mouse models carrying xenografts of human breast cancer to check whether the co-treatments we had implemented made it possible to preserve the hearing without compromising the anti-tumor efficacy of the CDDP. Our results show that CDDP induces DNA double-strand breaks in the hair cells that are responsible for the activation of the ATM-Chk2-p53 pathway and, ultimately, for the death of these cells by apoptosis. . We have also shown that the absence of p53 in vivo prevents hearing loss and external hair cells degeneration upon intraperitoneal injection of CDDP. The systemic or local treatment using the p53 inhibitor PFT-α effectively prevents hearing loss without compromising the anti-tumor efficacy of CDDP.The second objective of my thesis was to identify the links between the overproduction of reactive oxygen species (ROS), DNA damage, markers of cell senescence and age-related hearing loss. To do this, I used cochlear explants of 3-days old mice treated with increasing concentrations of hydrogen peroxide (H2O2). The appearance of DNA damage and senescent cells was investigated using immunolabeling and Western blotting technics. The results obtained in vitro were then validated in vivo on cochleae from SAMP8 (Senescence Accelerated Mouse Prone 8) and SAMR1 (Senescence Accelerated Mouse Resistant 1) mice. In order to confirm the role of oxidative stress in the early onset of presbycusis, we used a mouse line invalidated for the P66Shc gene, which is a stress adaptation gene known for its roles in ROS overproduction and in the inhibition of antioxidant enzymes. Finally, we assessed the possibility of preventing or slowing-down age-related hearing loss by treating SAMP8 mice with a SOD/catalase mimetic; EUK207. Our results showed that: i) overproduction of ROS is one of the major causal factors of age-related cochlear sensorial cells degeneration; ii) Activation of the p53-p21 pathway resulting in the early onset of senescence in postmitotic cochlear cells may explain premature aging of the cochlea; iii) EUK207 which is a superoxide and hydrogen peroxide scavenger, can attenuate ARHL in SAMP8 mice.All together our results highlight innovative and effective strategies for hearing protection.

Made available in DSpace on 2014-06-11T19:22:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-12-05Bitstream added on 2014-06-13T19:27:31Z : No. of bitstreams: 1 vellosa_jcr_me_arafcf.pdf: 1352402 bytes, checksum: 1fb4f8a94f0db92c39104b3590886eff (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A relevância da pesquisa de produtos naturais proporciona a descoberta de novos fármacos e o estudo de plantas que apresentem substâncias que possam agir sobre as diferentes espécies oxidantes geradas em nosso organismo torna-se de grande importância. No estudo da avaliação do potencial antioxidante das amostras deve-se considerar que: i) um composto deve ser testado em concentrações disponíveis in vivo e ii) ao avaliar os antioxidantes, deve-se utilizar pelo menos uma espécie relevante biologicamente. Deve-se perguntar como age o antioxidante, se ele age diretamente sobre a ERO ou ele inibe a sua geração e ainda, se ele age indiretamente regulando defesas antioxidantes endógenas. Foram avaliados extratos ou moléculas dos vegetais: Pterogyne nitens, Maytenus ilicifolia, Maytenus aquifolium, Salacia campestris, Piper gaudichaudianum, Piper crassinervium e Piper aduncum. A proposta deste trabalho é: i) avaliar a possibilidade de ação direta destas amostras sobre diferentes espécies reativas modelo e geradas em nosso organismo e ii) avaliar a inibição da mieloperoxidase, enzima envolvida em diferentes patologias. Observamos um grande potencial das plantas estudadas como fonte de compostos com ação antioxidante. Destacam-se as frações hidroalcoólicas e hexano-acetato da M. ilicifolia e M. aquifolium sobre o ânion superóxido. Além disso, identificou-se a existência de possíveis inibidores da MPO nos diferentes vegetais estudados, destacando-se quercetina (IC50=1,35mg/mL), 3-HexAcOEt (IC50=1,5mg/mL), 2-Hid (IC50=2,2mg/mL), 3-Hid (IC50=3,1mg/mL), S-3 (IC50=3,1mg/mL), 2-HexAcOEt (IC50=4,4mg/mL), 1C-BuOH (IC50=6,4mg/mL) e 4EtOH (IC50=8,9mg/mL). Por fim, caracterizou-se o tipo de inibição promovida pela S-3 (1,4-diidroxi-2-(3',7'-dimetil-1'-oxo-2'-E-6'-octadienil) benzeno) e pela quercetina como sendo do tipo mista. / Phagocytes, mainly polimorphonuclear neutrophils leucocytes, yield superoxide radical (O2 -), expending NADPH. By this process, many reactive species, such as HOCl, HO, ONOO -, are generated. These oxidants are made to fight microorganisms, but they are involved in many pathologies. Reactive species and free radicals generation are equilibrated by antioxidants. The search of new medicines turns natural products research an important option for discovering molecules with different biological activities. Natural products research is relevant for discovering new medicines and molecules able to fight oxidant species. In evaluating the antioxidant potential of substances, it is important considerate: i) a compound should be tested at concentrations achievable in vivo and ii) in assaying putative antioxidants, one should use biologically relevant ROS. It is important to ask if it works directly over the oxidant or it works by regulating endogenous antioxidants defenses. In this work, Pterogyne nitens, Maytenus ilicifolia, Maytenus aquifolium, Salacia campestris, Piper gaudichaudianum, Piper crassinervium and Piper aduncum were studied. The purpose of this work is: i) evaluate direct action of samples over different reactive species and ii) evaluate myeloperoxidase inhibition, an important enzyme involved in different pathologies. We observed that different evaluated plants are efficient sources of antioxidants. Moreover, different samples were able to inhibit myeloperoxidase, detaching quercetin (IC50=1,35mg/mL), 3-HexAcOEt (IC50=1,5mg/mL), 2-Hid (IC50=2,2mg/mL), 3-Hid (IC50=3,1mg/mL), S-3 (IC50=3,1mg/mL), 2-HexAcOEt (IC50=4,4mg/mL), 1C-BuOH (IC50=6,4mg/mL) and 4EtOH (IC50=8,9mg/mL). Besides, quercetin and S-3 (1,4-dihydroxi-2-(3',7'-dimethyl- 1'-oxo-2'-E,6'-octadienyl) benzene) were characterized as mixed MPO inhibitors.

TÍTULO: Associação entre Distúrbios Respiratórios do Sono, Estresse Oxidativo e Doença Arterial Coronariana. INTRODUÇÃO: Evidências sugerem associação entre a doença arterial coronariana (DAC) e os distúrbios respiratórios do sono (DRS), porém o mecanismo que explica essa associação é incerto. Episódios repetitivos de hipóxia e reoxigenação vivenciados pelos indivíduos com DRS levam ao aumento de espécies reativas de oxigênio (ERO). ERO no interior dos eritrócitos podem ser detoxificadas pelas enzimas antioxidantes glutationa peroxidase (GPx), catalase (CAT) e superóxido dismutase (SOD). Ainda no citoplasma as ERO podem ser detoxificadas pela vitamina C ou ácido úrico. O estresse oxidativo é caracterizado por um desequilíbrio entre os níveis de ERO e antioxidantes. Este desequilíbrio promove lesão oxidativa em biomoléculas, mecanismo este associado à fisiopatologia da DAC. OBJETIVOS: Verificar a relação entre o índice de apnéia hipopnéia (IAH) e a presença de DAC. Verificar a associação entre IAH, DAC e a atividade das enzimas antioxidantes: SOD, CAT, GPx e antioxidantes não enzimáticos, ácido úrico e vitamina C. Avaliar a relação entre IAH, DAC e os produtos de danos oxidativos em lipídios, proteínas. Entre os marcadores de estresse oxidativo identificar preditores para DAC. MATERIAIS E MÉTODOS: Estudo transversal. Entre junho de 2007 e maio de 2008 na Hemodinâmica do Hospital de Clínicas de Porto Alegre, triamos consecutivamente 519 indivíduos encaminhados para angiografia diagnóstica ou terapêutica. Incluímos 14 pacientes com DAC (≥ 50% diminuição do lúmen da coronária) e 30 controles com < 50% de obstrução. O IAH foi mensurado por meio de polissonografia portátil. Verificamos presença de DAC através da angiografia coronariana. A quantificação dos grupos carbonil no hemolisado e no plasma e as atividades das enzimas antioxidantes SOD, CAT e GPx foram verificadas por método espectrofotométrico. Mensuramos malondialdeído (MDA) e vitamina C por cromatografia líquida de alta eficiência. RESULTADOS: Este é o primeiro trabalho que evidencia correlação entre IAH e o aumento de carbonilação de proteínas eritrocitárias. Além disso, os resultados obtidos mostram que os indivíduos portadores de DAC apresentam níveis maiores de grupos carbonil no hemolisado quando comparados aos indivíduos controles. Em um modelo de regressão multivariado ajustado para idade, sexo e índice de massa corporal, buscando verificar preditores para DAC, verificamos que o aumento de uma unidade de carbonil aumenta 1,7% o risco para desenvolvimento de DAC, já uma unidade do IAH aumenta em 3,9% o risco de desenvolvimento de DAC. Não foi encontrada correlação entre IAH e os marcadores MDA, carbonil no plasma e os antioxidantes: SOD, CAT, GPx vitamina C e ácido úrico. Não verificamos correlação entre DAC e os marcadores MDA, carbonil no plasma e entre os antioxidantes SOD, CAT , GPx e ácido úrico. Pacientes com CAD significativa apresentaram níveis menores de vitamina C. Correlação positiva foi observada entre os níveis de vitamina C e a concentração de proteínas carboniladas no plasma. CONCLUSÃO: Foi evidenciado que a carbonilação de proteínas eritrocitárias e o IAH tem importância na fisiopatologia da DAC. Da mesma forma a vitamina C parece ter importância na prevenção da DAC. / INTRODUCTION: Evidences suggest association between Coronary Artery Disease (CAD) and Sleeping Disordered Breathing (SDB), however the mechanism is uncertain. Repetitive episodes of hypoxia and reoxygenation experienced by individuals with SDB lead to an increase of Reactive Oxygen Species (ROS). ROS inside the erythocytes may be scavenging by glutathione peroxidase antioxidants enzymes (GPx), catalase (CAT) and superoxide dismutase (SOD). In the cytoplasm ROS may be inhibited by vitamin C, or uric acid. Oxidative stress is characterized by an unbalance between ROS and antioxidants. These unbalance promotes oxidative damage in biomolecules, this mechanism is associated to the CAD physiopathology . OBJECTIVE: Verify the relation between apnea hypopnea index (AHI) and CAD. Verify association between AHI, CAD and antioxidants enzymes activity: SOD, CAT, GPx and non enzymatic antioxidants, uric acid, and vitamin C. Evalute the relation between AHI, CAD and oxidative damage products in lipids and proteins. Among the oxidative stress markers identify the predictors for CAD. MATERIALS AND METHODS: Cross sectional study. Between June and May 2008 in the hemodinamic ward of Clinicas Hospital of Porto Alegre, we consecutively screened 519 individuals sent for diagnostic or therapeutic angiography. We included 14 cases with CAD (≥ 50% narrowing of coronary lumen) and 30 controls with < 50% narrowing. The AHI was measured by portable polisomnography. We found the presence of CAD through coronary angiography. Carbonyl groups quantification in the hemolysed and plasma and antioxidants enzyme activities of SOD, CAT and GPx were verified by spectophotometric method. Malondyaldeyde (MDA) and vitamin C were measured by HPLC. RESULTS: This work is the first one that shows correlation between AHI and increased erythrocytes protein carbonylation. In the same way evidences that individuals with significant CAD compared to controls present higher levels of carbonyl groups in the hemolysates. In a multivaried regression model adjusted to age, gender and body mass index to verify predictors for CAD, we verified that the carbonyl unit increased 1.7% the risk for development of CAD, while one unit of IAH increased in 3.9% the risk to develop CAD. We did not find correlation between AHI and the markers MDA, plasma carbonyl and the antioxidants: SOD, CAT, GPx vitamin C and uric acid. We didn’t verify correlation between CAD and the markers MDA, plasma carbonyl and the others antioxidants SOD, CAT , GPx and uric acid. Patients with significant CAD had lower levels of vitamin C. Positive correlation was observed between vitamin C and erythrocyte carbonyl concentration. CONCLUSION: We evidenced that erythrocytes protein carbonylation and AHI are important in the physiopathology of CAD. In the same way vitamin C appears important factor in CAD prevention.

O uso de tetracloreto de carbono (CCl4) em ratos é um modelo experimental de dano ao tecido hepático, desencadeando fibrose e, a longo prazo, cirrose. Seu metabolismo ocorre no fígado pelo citocromo P450, resultando na produção de radicais livres e estimulação da lipoperoxidação, que induz um processo de necrose, inflamação e maior progressão da fibrose. Vários antioxidantes, entre eles os flavonoides, têm sido referidos como eficazes para diminuir a fibrose em modelos animais. Este estudo pretende avaliar a ação antioxidante da quercetina (Q) em um modelo experimental de cirrose induzida por CCl4 inalatório. Foram utilizados 25 ratos Wistar machos, com peso médio de 250g, divididos em 3 grupos: Controle (CO), CCl4 e CCl4+Q. Os ratos foram submetidos a inalações de CCl4 (2x/semana), durante 16 semanas, recebendo fenobarbital na água de beber na dose de 0,3g/dl, como indutor enzimático. A Q (50mg/Kg) via intraperitoneal foi iniciada na 10ª semana de inalação, perdurando até o final do experimento. A análise estatística foi ANOVA, seguida de Student Newmann Keuls (Média±SEM), considerando-se diferença estatisticamente significativa quando p<0,05. Após o tratamento com quercetina, observamos uma melhora na integridade hepática, diminuição da fibrose, do conteúdo de colágeno e re-estabelecimento nos níveis dos metabólitos do óxido nítrico, comparado ao grupo CCl4. Constatou-se também redução do dano oxidativo, verificada pela diminuição das substâncias que reagem ao ácido tiobarbitúrico (TBA-RS), assim como aumento na atividade das enzimas antioxidantes e da relação GSH/GSSG. A partir desses dados, sugerimos que o emprego da quercetina possa ser promissor como terapia antioxidante nas complicações hepáticas. / Carbon tetrachloride (CCl4) is a classic experimental model of oxidative damage to liver tissue, causing long-term fibrosis and cirrhosis. Metabolism in the liver via cytochrome P450 results in the stimulation of lipid peroxidation and production of free radicals, which induce a process of necrosis, inflammation and greater progression of fibrogenesis. Various antioxidants and flavonoids have been identified as effective in reducing fibrosis in animal models. This study aimed to assess the antioxidant activity of quercetin (Q) in an experimental model of cirrhosis induced by CCl4 inhalation. We used 25 male Wistar rats (250g) that were divided into 3 groups: control (CO), CCl4 and CCl4 + Q. The rats were subjected to CCl4 inhalation (2x/week) for 16 weeks, and they received phenobarbital in their drinking water at a dose of 0.3 g/dl as a P450 enzyme inducer. Q (50 mg/Kg) was initiated intraperitoneally at 10 weeks of inhalation and lasted until the end of the experiment. Statistical analysis was by ANOVA Student-Newman Keuls (mean ± SEM), and differences were considered statistically significant when p <0.05. After treatment with quercetin, we observed an improvement in liver integrity, decreased fibrosis, as analyzed by picrosirius for the quantification of collagen, and restored levels of nitric oxide metabolites compared with the CCl4 group. It also reduced oxidative stress, as confirmed by the decrease of substances reacting to thiobarbituric acid (TBARS), the increased activity of antioxidant enzymes and the reduced glutathione ratio and glutathione disulfide (GSH/GSSG). From these data, we suggest that the use of quercetin might be promising as an antioxidant therapy in liver complications.

Cerca de 30% dos pacientes com epilepsia continuam refratários ao tratamento medicamentoso e continuam a sofrer crises, mesmo utilizando um ou mais fármacos antiepilépticas. Intervenções não farmacológicas representam uma alternativa aos fármacos antiepilépticos, dentre as quais a acupuntura, uma técnica tradicional chinesa, que é freqüentemente utilizada como tratamento complementar na medicina ocidental. O objetivo deste estudo foi avaliar o efeito da acupuntura manual sobre as convulsões no modelo de kindling induzido por pentilenotetrazol (PTZ) em camundongos, comparar o efeito da acupuntura com diazepam, avaliar a sua utilização em associação a uma dose baixa de diazepam, e avaliar parâmetros de estresse oxidativo, inflamação, genotoxicidade e mutagenicidade. No modelo de kindling, os animais dos grupos que receberam acupuntura manual, foram tratados diariamente durante 16 dias com estimulação no acuponto VG20, e a cada três dias os animais receberam o salina ou diazepam (0,15 mg / kg; i.p.) 30 min antes da administração de PTZ (60 mg / kg; s.c.). Nos grupos que não receberam acupuntura manual, os animais receberam salina, diazepam (2 mg / kg; i.p. - controle positivo), diazepam (0,15 mg / kg; i.p.), 30 min antes da administração de PTZ (60 mg / kg; s.c.). O comportamento convulsivo (porcentagem de convulsão e latência para a primeira convulsão) foi observado por 30 min. Após o último tratamento, os animais foram eutanasiados e o córtex, hipocampo, sangue periférico e medula óssea foram coletados para avaliação dos parâmetros de estresse oxidativo, inflamação, genotoxicidade e mutagenicidade. Os dados de porcentagem (%) de convulsão e latência para a primeira convulsão (LFS) foram analisados pelo Teste de Fisher e GEE respectivamente. MAC e MAC + DZP 0.15mg/Kg não impediram a ocorrência das convulsões, nem aumentaram a LFS, com exceção do terceiro dia de tratamento, no qual observou-se aumento na LFS no grupo MAC + DZP 0.15mg/Kg, comportamento que não se repetiu ao longo do protocolo. Observou-se nos grupos MAC e MAC + DZP 0.15mg/Kg uma redução na formação de espécies reativas de oxigênio e na liberação de óxido nítrico, bem como aumento na atividade de SOD e CAT, sugerindo que a acupuntura oferece proteção contra estresse oxidativo. Além disso, nos mesmos grupos verificou-se a redução na expressão da citocina pró-inflamatória (TNF-α). No grupo MAC + DZP 0.15mg/Kg observou-se uma tendência à proteção do DNA no hipocampo, uma vez que não houve diferença em comparação ao grupo Sal/Sal, contudo não foi observada mutagenicidade em nenhum dos grupos de tratamento. Para concluir, os resultados indicaram que MAC em associação ao DZP 0.15mg/Kg foi capaz de alterar parâmetros associados a convulsões mediada por PTZ no modelo de kindling em camundongos, bem como a acupuntura teve um efeito protetor contra estresse oxidativo, neuroinflamação e danos ao DNA no mesmo modelo. / Around 30% of patients with epilepsy continue refractory to drug treatment and continue to suffer crises, even using one or more anti-epileptic drugs. Nonpharmacological interventions represent an alternative to antiepileptic drugs, among which acupuncture, a traditional Chinese technique, which is often used as a complementary treatment in Western medicine. The aim of this study was to evaluate the effect of manual acupuncture on seizures in the kindling model induced by pentylenetetrazol (PTZ) in mice, comparing the effect of acupuncture with diazepam, to evaluate their use in combination with a low dose of diazepam, and evaluate parameters of oxidative stress, inflammation, genotoxicity and mutagenicity. In the model of kindling, the animal groups receiving manual acupuncture, were treated daily for 16 days with stimulation of the acupoint VG20, and every three days the animals received saline or diazepam (0.15 mg / kg, ip) 30 min before PTZ administration (60 mg / kg, sc). In the groups not receiving manual acupuncture, the animals received saline, diazepam (2 mg / kg, ip - positive control), diazepam (0.15 mg / kg, ip) 30 min before the PTZ administration (60 mg / kg ; sc). The convulsive behavior (percentage of seizure and latency to the first seizure) was observed for 30 min. After the last treatment, the animals were euthanized and the cortex, hippocampus, peripheral blood and bone marrow were collected for evaluation of parameters of oxidative stress, inflammation, genotoxicity and mutagenicity. Percentage of seizure (%) and latency to the first seizure (LFS) were analyzed by Fisher test and GEE respectively. MAC and MAC + DZP 0.15mg / kg did not prevent the occurrence of seizures or increased LFS, except for the third day of treatment, in which there was an increase in LFS in the MAC + DZP 0.15mg / kg group, behavior that was not repeated throughout the protocol. It was observed in the MAC and MAC + DZP 0.15mg / kg groups a reduction in the formation of reactive oxygen species and release of nitric oxide and increase in SOD and CAT activity, suggesting that acupuncture provides protection against oxidative stress. Furthermore, in the same groups there was a reduction in the expression of pro-inflammatory cytokine (TNF-α). In the MAC + DZP 0.15mg / kg group there was a tendency to protect DNA in hippocampus since there was no difference in comparison to Sal/Sal group, however mutagenicity was not observed in any of the treatment groups. In conclusion, the results indicated that MAC in association with DZP 0.15mg / kg was able to change parameters associated with seizures mediated in PTZ kindling model in mice, also suggested that acupuncture had a protective effect against oxidative stress, neuroinflammation and damage DNA in the same model.

Submitted by Carvalho Dias João Paulo (joao.dias@famerp.br) on 2018-04-10T18:32:44Z No. of bitstreams: 1 fabioborghi_dissert.pdf: 2895909 bytes, checksum: 286f9c8710bbee1509e1bba599cc0e05 (MD5) / Made available in DSpace on 2018-04-10T18:32:44Z (GMT). No. of bitstreams: 1 fabioborghi_dissert.pdf: 2895909 bytes, checksum: 286f9c8710bbee1509e1bba599cc0e05 (MD5) Previous issue date: 2016-09-26 / Introduction: Schizophrenia is a complex Neuropsychiatric disorder of uncertain etiology. About 30% of the affected population do not respond to the usual treatment with antipsychotic medication, therefore, they are considered a subgroup of refractory schizophrenics. Several different lines of research has been developed to understand the mechanisms related to the pathophysiology of Schizophrenia, standing out the role of oxidative stress. Objectives: To evaluate the oxidative stress biomarkers in Schizophrenia, and uncover a possible association to patients known to be refractory to antipsychotic treatment, also comparing positive and negative symptoms of schizophrenia on the schizophrenic population currently being treated at a tertiary healthcare center. Methods: Eightynine individuals were selected and divided into three groups: G1 - 36 healthy subjects (control group); G2 - 26 non-refractory schizophrenia patients; G3 - 27 refractory schizophrenia patients. All patients met the criteria for Schizophrenia diagnosis, as proposed by DSM-IV (Diagnostic and Statistical Manual of Mental Disorders). The Kane et al. criteria and IPAP algorithms (International Psychopharmacology Algorithm Project) were also used to determine the presence of clinically refractory Schizophrenia. Clinical and sociodemographic data of groups were collected, analyzed and compared. For the clinical assessment of the patient’s psychopathological state, the PANSS (Positive and Negative Syndrome Scale) tool was used. The patients had peripheral blood drawn for the measurements of oxidative stress biomarkers: malondialdehyde (MDA), total antioxidant capacity (TEAC), catalase (CAT) and glutathione peroxidase (GSH-Px), using the methodology of high performance liquid chromatography resolution and spectrophotometry. The Chi-Square test (χ2), Fisher’s exact test and Mann- Whitney non-paired test were used for statistical analysis. Results: There was MDA and CAT increase in the patient groups (G2 and G3) as compared to the control group (G1). The enzymatic activity of GSH-Px was reduced in G2 and G3 as compared to the control group. TEAC plasma levels remained similar among all groups. There was no statistic relevant difference among the patient groups concerning the analysis of all the studied biomarkers (MDA, TEAC, CAT and GSHPx). The scores obtained by the PANSS scale also showed no differences between the two groups of patients. The patient groups were similar on sociodemographic and lifestyle habits. Conclusion: Serum MDA, CAT and GSHPx were positively associated to Schizophrenia, unlike TEAC, which was not associated to this condition. Regarding clinical refractority, none of the studied biomarkers was associated to this schizophrenia characteristic, as well as the scores obtained by the PANSS, sociodemographic data and lifestyle habits. / Introdução: A Esquizofrenia é uma doença neuropsiquiátrica complexa, cuja etiologia permanece incompletamente desvendada. Cerca de 30% dos pacientes mostram-se resistentes ao tratamento com medicamentos antipsicóticos, sendo considerados esquizofrênicos refratários. Diversas linhas de pesquisa têm sido desenvolvidas em busca da compreensão dos mecanismos envolvidos na fisiopatologia da Esquizofrenia, com destaque para o papel do estresse oxidativo. Objetivo: Avaliar biomarcadores de estresse oxidativo associados a pacientes com Esquizofrenia, refratários e não refratários ao tratamento antipsicótico e comparar sintomas positivos e negativos em pacientes esquizofrênicos acompanhados em um serviço terciário. Casuística e Método: Foram selecionados 89 indivíduos, divididos em três grupos: G1 - 36 indivíduos saudáveis (grupo controle); G2 - 26 pacientes com Esquizofrenia não refratária; G3 - 27 pacientes com Esquizofrenia refratária. Todos os pacientes preencheram critérios para o diagnóstico de Esquizofrenia, firmado de acordo com o DSM-IV (Manual Diagnóstico e Estatístico de Transtornos Mentais). Os critérios de Kane et al. e os algoritmos do IPAP (International Psychopharmacology Algorithm Project) foram usados para determinar a refratariedade clínica da Esquizofrenia. Os dados clínicos e sociodemográficos dos grupos foram coletados, analisados e comparados. Para a avaliação clínica do estado psicopatológico dos pacientes, foi aplicada a PANSS (Escala das Síndromes Positiva e Negativa). Os pacientes foram submetidos à coleta de sangue periférico para dosagens dos biomarcadores de estresse oxidativo: malondialdeído (MDA), capacidade antioxidante total (TEAC), catalase (CAT) e glutationa peroxidase (GSH-Px), realizados por cromatografia líquida de alta resolução e espectrofotometria. As análises estatísticas compreenderam os testes Qui-quadrado (χ2), teste exato de Fisher e teste não pareado de Mann-Whitney. Resultados: Foi observada elevação de MDA e CAT nos grupos de pacientes (G2 e G3) em relação ao grupo controle (G1). A atividade enzimática de GSH-Px mostrou-se reduzida nos grupos G2 e G3, quando comparada ao grupo controle. Os níveis plasmáticos de TEAC permaneceram semelhantes entre todos os grupos estudados. Não houve diferença estatisticamente significativa entre os grupos de pacientes (G2 e G3) em relação à análise de todos os biomarcadores estudados (MDA, TEAC, CAT e GSH-Px). Os escores obtidos por meio da escala PANSS não evidenciaram diferenças entre os dois grupos de pacientes (G2 e G3). Os grupos de pacientes mostraram-se semelhantes em relação aos dados sociodemográficos e hábitos de vida estudados. Conclusão: Níveis séricos de MDA, CAT e GSH-Px estão associados à Esquizofrenia, diferentemente de TEAC, que não se associou a essa patologia. Em relação à refratariedade clínica, nenhum dos biomarcadores estudados mostrou associação a essa característica da Esquizofrenia, assim como os escores obtidos pela PANSS, dados sociodemográficos e hábitos de vida.

Le premier objectif de cette thèse était d’améliorer l’utilisation et la compréhension des outils de mesure de la déformabilité du globule rouge (GR) dans la drépanocytose (Etudes 1 et 2). L’étude 1 a montré l’importance de la standardisation des mesures de déformabilité par ektacytométrie chez les enfants drépanocytaires. Au cours de l’étude 2, les propriétés des GR ont été modifiées et la variation des courbes de déformabilité érythrocytaire « classique » (index d’élongation en fonction de la contrainte de cisaillement en milieu isotonique) a été comparée aux résultats d’osmoscan (mesure de la déformabilité érythrocytaire en gradient osmolaire à contrainte de cisaillement fixe), méthode de référence pour étudier les anomalies de la membrane du GR. Ainsi, les variations de déformabilité érythrocytaire au-delà de 3 Pa sont affectées à la fois par la viscosité interne du GR et par des modifications de la surface cellulaire (rapport surface/volume) alors que les modifications de l’élasticité membranaire affectent la déformabilité érythrocytaire quelles que soient les forces de cisaillements utilisées (faibles, modérées ou hautes). Le deuxième objectif de cette thèse était d’apporter des éléments supplémentaires sur l’implication des facteurs génétiques, des paramètres hémorhéologiques et du niveau de stress oxydant sur la survenue des complications vaso-occlusives chez les patients atteints de syndrome drépanocytaire majeur (Etudes 3 à 6). La mise en commun des résultats d’hémorhéologie obtenus sur 165 patients de notre cohorte lyonnaise et 240 patients de la cohorte guadeloupéenne a permis de montrer que la rhéologie du GR chez les patients drépanocytaires était dépendante de l’âge. Ainsi, la viscosité sanguine augmente avec l’âge pour atteindre un plateau vers 30 ans alors que la déformabilité érythrocytaire diminue avec l’âge (Etude 3). Ces modifications participent vraisemblablement à l’apparition de complications chroniques chez l'adulte drépanocytaire. Les études 4 et 5 ont été réalisées sur la cohorte pédiatrique lyonnaise. Au cours de ces 2 études, nous avons étudié l’influence sur la rhéologie du sang et la survenue de crises vaso-occlusives (CVO) des facteurs génétiques (alpha-thalassémie, déficit en Glucose-6-Phosphate Déshydrogénase (G6PD) et haplotypes S) d’une part (Etude 4) et du niveau de stress oxydant et nitrosatif d’autre part (Etude 5). L’alpha-thalassémie augmente la déformabilité des GR et l’agrégation érythrocytaire. Ces 2 phénomènes pourraient participer à augmenter le risque de CVO. De plus, l’alpha-thalassémie, en diminuant l’hémolyse, diminuerait le niveau de stress oxydant, élément majeur impliqué dans la physiopathologie de la drépanocytose. Enfin, l’étude 6 a montré que la rhéologie sanguine des patients Sbêta+ était quasi-identique à celle des sujets sains AA mais que les patients les plus sévères pourraient avoir un déficit en monoxyde d’azote circulant. En conclusion, mon travail de thèse contribue à une meilleure compréhension de la physiopathologie de la drépanocytose / The first goal of this thesis (Study 1 and 2) was to improve the use and the comprehension of tools for red blood cell (RBC) deformability measurements in sickle cell disease (SCD). The first study showed the importance of standardization of RBC deformability measurements by ektacytometry in SCD children. In the study 2, the RBC proprieties was modified and the variation of « classic » RBC deformability curve (elongation index as a function of the shear stress in isotonic medium) was compared to osmoscan results (elongation index in hyperosmolar gradient and constant shear stress), the gold standard for RBC membrane defect studies. Thus, the modifications of RBC deformability curve above 3 Pa were affected by RBC internal viscosity and cellular surface modification (and thus surface/volume ratio) while membran elasticity modifications affected RBC deformability whatever the shear stress (low, moderate or high). The second goal of this thesis was to study the effects of genetic modifiers, hemorheological parameters and oxidative stress level on vaso-occlusive complications (VOC) in SCD (Study 3 to 6). Hemorheological parameters were measured on 165 patients from Lyon and 240 patients from Gwada and the results showed that blood viscosity increased until the age of 30 and RBC deformability decreased with age (Study 3). This modifications probably play role in the chronic complications of SCD adult patients. The studies 4 and 5 were conducted on SCD children. We studied the effects of genetic modifiers (alpha-thalassemia, glucose-6-phospho-deshydrogenase deficiency and S haplotypes ; study 3) and nitro-oxidative stress level (study 5). Alpha-thalassemia increase RBC deformability and RBC aggregation. This phenomenon could contribute to increase VOC. Moreover, alpha-thalassemia decreased hemolysis and thus oxidative stress, a major component of SCD physiopathology. Then the study 6 showed that Sbeta+ patient hemorheology was quite the same of AA ubjects but the more severe patients could have a defect in circulating nitric oxide. To conclude, my thesis contribute to a better understanding of SCD physiopathology

O estresse oxidativo pode desempenhar um papel importante na etiologia das complicações no diabetes mellitus. O aumento da produção de espécies oxidantes promove modificações em moléculas endógenas, incluindo o colesterol. Os óxidos de colesterol (Cox) são formados a partir da oxidação do colesterol, por processos enzimáticos e por processos mediados por radicais livres, apresentando importantes efeitos biológicos que podem contribuir para o desenvolvimento do processo aterosclerótico no diabetes. Nesse estudo determinou-se as concentrações dos Cox, em pacientes diabéticos e indivíduos intolerantes à glicose, para estabelecer se os COx são marcadores sensíveis da lipoperoxidação na intolerância à glicose e no diabetes As concentrações plasmáticas dos COx foram determinadas por GC-FID nos seguintes grupos: diabéticos tipo 1 (DM1), diabéticos tipo 2 (DM2), intolerantes à glicose (IGT) e normoglicêmicos (controles). As concentrações dos óxidos de colesterol totais foram mais elevadas nos grupos DM1 e DM2 em relação aos controles normoglicêmicos (p<0,05). As concentrações plasmáticas do 7&#945;- hidroxicolesterol (7&#945;-OH), 7&#946;-hidroxicolesterol (7&#946;-OH) e 25- hidroxicolesterol (25-OH) foram mais elevadas no grupo DM1 comparado ao grupo DM2 (p<0.05). A comparação entre os grupos controle, IGT e DM 2 indicou aumento significativo das concentrações de 7&#946;-OH, colesterol-&#946;- epóxido e colesterol-&#945;-epóxido no grupo DM 2 (p<0.05). Portanto, os óxidos de colesterol podem ser considerados como um biomarcador sensível da lipoperoxidação para indicar a intensidade de modificação oxidativa dos lípides em pacientes diabéticos. / Oxidative stress can play an important role in the etiology of the complications of diabetes mellitus. The increase in the production of oxidant species promotes alterations in endogenous molecules, including cholesterol. Cholesterol oxides (COx) are formed by the oxidation of cholesterol by enzymatic processes or by processes involving free radicals. They present important biological effects that can contribute to the development of the atherosclerotic process in diabetes. In this study, the concentrations of the COx in diabetic patients and individuals who are intolerant to glucose was determined in order to establish whether the Cox are sensitive markers of lipoperoxidation in glucose intolerance and diabetes. Serum concentrations of the COx were determined by GC-FID in the following groups: Type 1 diabetics (DM1), type 2 diabetics (DM2), patients intolerant to glucose (IGT) and normoglycemic subjects (controls). The concentrations of total cholesterol oxides were found to be elevated in the DM1 and DM2 groups with respect to the normoglycemic subjects (p<0.05). The serum concentrations of 7&#9465- hydroxicholesterol (7&#945;-OH), 7&#946;-hydroxicholesterol (7&#$946;-OH) and 25-hydroxicholesterol (25-OH) were found to be increased in the DM1 group with respect to the DM2 group (p<0.05). The comparison between the control, IGT and DM2 groups indicated a significant increase in the concentrations of 7&#946;-OH, cholesterol-&#946;-epoxide and cholesterol-&#945;-epoxide in the DM2 group (p<0.05). In conclusion, cholesterol oxides could serve as suitable biomarker of lipoperoxidation to indicate the intensity of lipid oxidative mofications in diabetic patients.