O stresse oxidativo na fisiopatologia da doença periodontal do cão um projeto de investigação
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2019-03-27
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A doença periodontal constitui uma parte relevante na saúde do cão, visto que traz consequências devastadoras para a cavidade oral e é uma potencial causa de diversas doenças sistémicas (quer devido à translocação bacteriana, quer devido à ocorrência de fenómenos de stresse oxidativo). Além disso, acomete a maioria da população canina e as técnicas de tratamento atualmente utilizadas não permitem reestabelecer totalmente a funcionalidade do periodonto. É uma doença caracterizada pela inflamação dos tecidos periodontais, como resposta imunitária do indivíduo à presença de bactérias e respetivas toxinas na placa bacteriana (fator determinante ao desenvolvimento da doença), estando também envolvidos outros fatores (predisponentes) no seu aparecimento e desenvolvimento. É, portanto, uma doença multifatorial. As principais células envolvidas na resposta inflamatória são leucócitos polimorfonucleares, que produzem naturalmente espécies reativas de oxigénio (ROS), capazes de causar danos moleculares no ADN, lípidos e proteínas. Quando estas estão em excesso, a defesa antioxidante deixa de ser suficiente para a sua neutralização, surgindo o stresse oxidativo, que pode ter repercussões negativas a vários níveis. Este trabalho tem como objetivo principal o contributo para o desenho de um projeto de investigação, que incidirá na avaliação dos seguintes parâmetros, em cães com diferentes graus de doença periodontal: biomarcadores do dano molecular causado pelo stresse oxidativo, nomeadamente a 8-hidroxi-2-deoxiguanosina (8-OHdG), o malondialdeído (MDA) e os tióis não proteicos (GSH e GSSG); algumas das principais enzimas antioxidantes, nomeadamente a catalase (CAT), superóxido dismutase (SOD), glutationa peroxidase (GPx) e glutationa redutase (GR); assim como a capacidade antioxidante total (TAOC); e a eficácia da aplicação de antioxidantes e de células-tronco provenientes de tecido adiposo como coadjuvantes do tratamento da doença. O estudo visa melhorar a compreensão da fisiopatologia da doença periodontal no cão e abrir novas perspetivas para o tratamento da mesma.
Periodontal disease constitutes an important part of dog’s health, since it brings devastating consequences for the oral cavity, while also being a potential cause of several systemic diseases (either due to bacterial translocation or because of the oxidative stress phenomena). Moreover, this is a problem which affects most of the canine population and to which the treatment techniques currently used do not allow the full reestablishment of the periodontium’s functionality. This disease is characterized by periodontal tissue inflammation which arises as the individual’s immune response to the presence of bacteria and their respective toxins in the dental plaque (determinant factor for the development of the disease), as well as other predisposing factors that are involved in its appearance and development – it is, therefore a multifactorial disease. The main cells involved in this inflammatory response are polymorphonuclear leukocytes which naturally produce reactive oxygen species (ROS) which can cause molecular damage on DNA, lipids and proteins. When in excessive values, the antioxidant defenses no longer suffice for their neutralization, resulting in oxidative stress as a result which can have negative repercussions, to all levels. The presented study has as its main goal, the structuring of a research project which will focus on the evaluation of the following parameters, in dogs with different degrees of periodontal disease: Molecular damage biomarkers, caused by oxidative stress, more specifically, 8-hydroxy-2-deoxyguanosine ( 8-OHdG), the malondialdehyde (MDA), and nonprotein thiols (GSH and GSSG); and some of the major known antioxidants enzymes such catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GR); as well as the total antioxidant capacity and the efficacy of the applications of antioxidants and stem cells derived from adipose tissue as adjuncts to the treatment of the disease. This study aims to improve the understanding of the pathophysiology of dog’s periodontal disease and to open new perspectives for its treatment.
Periodontal disease constitutes an important part of dog’s health, since it brings devastating consequences for the oral cavity, while also being a potential cause of several systemic diseases (either due to bacterial translocation or because of the oxidative stress phenomena). Moreover, this is a problem which affects most of the canine population and to which the treatment techniques currently used do not allow the full reestablishment of the periodontium’s functionality. This disease is characterized by periodontal tissue inflammation which arises as the individual’s immune response to the presence of bacteria and their respective toxins in the dental plaque (determinant factor for the development of the disease), as well as other predisposing factors that are involved in its appearance and development – it is, therefore a multifactorial disease. The main cells involved in this inflammatory response are polymorphonuclear leukocytes which naturally produce reactive oxygen species (ROS) which can cause molecular damage on DNA, lipids and proteins. When in excessive values, the antioxidant defenses no longer suffice for their neutralization, resulting in oxidative stress as a result which can have negative repercussions, to all levels. The presented study has as its main goal, the structuring of a research project which will focus on the evaluation of the following parameters, in dogs with different degrees of periodontal disease: Molecular damage biomarkers, caused by oxidative stress, more specifically, 8-hydroxy-2-deoxyguanosine ( 8-OHdG), the malondialdehyde (MDA), and nonprotein thiols (GSH and GSSG); and some of the major known antioxidants enzymes such catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GR); as well as the total antioxidant capacity and the efficacy of the applications of antioxidants and stem cells derived from adipose tissue as adjuncts to the treatment of the disease. This study aims to improve the understanding of the pathophysiology of dog’s periodontal disease and to open new perspectives for its treatment.
Descrição
Trabalho de Projeto de Mestrado Integrado em Medicina Veterinária
Palavras-chave
Doença periodontal , cão , biomarcadores , stresse oxidativo , antioxidantes , células-tronco