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Signaling lsc1p-regulated cell death: the role of possible downstream mitochondrial mediators

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Resumo:Mitochondria play a vital role in energy production through oxidative phosphorylation and have an important function in the regulation of various other processes, including stress responses and cell death. They are considered the major source of reactive oxygen species, and an abnormal cellular redox homeostasis due to mitochondrial dysfunction has been implicated in the ageing process and increases the incidence of age-related disorders. In recent years, interest into the role of sphingolipids in mitochondria function, redox homeostasis and lifespan has greatly increased, since the regulation of sphingolipid metabolism may be of potential therapeutic relevance in pathologies associated with oxidative stress and ageing. Ceramide is a bioactive sphingolipid that modulates cellular processes such as apoptosis and ageing. Several protein targets, including ceramide-activated protein phosphatases, have been suggested to mediate the effects of ceramide but the signalling pathways involved remain poorly characterized. The yeast Saccharomyces cerevisiae has a well-defined genome and is a genetically tractable organism. Therefore, studies in this simple genetic model system may be helpful in defining the role of sphingolipids in mitochondrial function. The neutral sphingomyelinase nSMase2 is considered a major candidate for mediating ceramide signalling during stress responses and ageing. We have previously shown that Isc1p, the yeast orthologue of mammalian nSMase2, plays a key role in oxidative stress resistance and chronological lifespan. ISC1 deficiency affects redox status and iron homeostasis and increases cell death by apoptosis. This project aims to uncover the role of possible downstream mitochondrial mediators. The overall results will contribute to the characterization of the role of neutral sphingomyelinases and sphingolipid signalling in the modulation of mitochondria function to our understanding of processes associated with lipid-related disorders, including aging.
Autores principais:Campos, Vanessa Alexandra Martins de
Assunto:Ciências Naturais::Ciências Biológicas
Ano:2015
País:Portugal
Tipo de documento:dissertação de mestrado
Tipo de acesso:acesso restrito
Instituição associada:Universidade do Minho
Idioma:inglês
Origem:RepositóriUM - Universidade do Minho
Descrição
Resumo:Mitochondria play a vital role in energy production through oxidative phosphorylation and have an important function in the regulation of various other processes, including stress responses and cell death. They are considered the major source of reactive oxygen species, and an abnormal cellular redox homeostasis due to mitochondrial dysfunction has been implicated in the ageing process and increases the incidence of age-related disorders. In recent years, interest into the role of sphingolipids in mitochondria function, redox homeostasis and lifespan has greatly increased, since the regulation of sphingolipid metabolism may be of potential therapeutic relevance in pathologies associated with oxidative stress and ageing. Ceramide is a bioactive sphingolipid that modulates cellular processes such as apoptosis and ageing. Several protein targets, including ceramide-activated protein phosphatases, have been suggested to mediate the effects of ceramide but the signalling pathways involved remain poorly characterized. The yeast Saccharomyces cerevisiae has a well-defined genome and is a genetically tractable organism. Therefore, studies in this simple genetic model system may be helpful in defining the role of sphingolipids in mitochondrial function. The neutral sphingomyelinase nSMase2 is considered a major candidate for mediating ceramide signalling during stress responses and ageing. We have previously shown that Isc1p, the yeast orthologue of mammalian nSMase2, plays a key role in oxidative stress resistance and chronological lifespan. ISC1 deficiency affects redox status and iron homeostasis and increases cell death by apoptosis. This project aims to uncover the role of possible downstream mitochondrial mediators. The overall results will contribute to the characterization of the role of neutral sphingomyelinases and sphingolipid signalling in the modulation of mitochondria function to our understanding of processes associated with lipid-related disorders, including aging.