Desenvolvendo a Pesquisa Redox Além das Abordagens Convencionais: Novos Modelos Celulares em Níveis de Oxigénio Fisiológico para uma Descoberta Avançada de Biomarcadores e Triagem de Antioxidantes

The project's objectives are clear and ambitious, aiming to bridge a critical gap in translating findings from in vitro studies into a practical application, by establishing a more refined model for preclinical studies. Conventional cell culture conditions using atmospheric or hyperoxic levels of oxygen (~18-21% O2) do not replicate the physiological in vivo environment [4]. This discrepancy can lead to differential cellular behavior in vitro compared to in vivo conditions, particularly when studying oxygen-related mechanisms such as redox processes. Cells cultured under atmospheric oxygen conditions are under constitutive high levels of oxidative stress and exhibit reduced energy production, thereby impacting their response to external agents [4]. Controlling this artifact is crucial to obtain more relevant results in in vitro studies and improve the translation of findings to disease pathology and the development of successful therapeutics. While a few studies have considered physiological oxygen levels [15], this has been limited to some particular research areas, such as the cardiovascular and cancer field [4], and none have focused on performing a comprehensive molecular characterization with a special focus on redox alterations. In this sense, it is expected that the shift to the physioxia concept (culturing cells under levels of oxygen like those measured in the tissues) will take some time to occur, making this an unexplored field. PhysOxy4Redox is an ambitious work that will break with conventional cell culturing conditions and raise awareness to the importance of using physiological oxygen levels during in vitro experimentation, particularly when involved the study of oxidative stress. To achieve its ultimate goal – creating a better in vitro model to study redox response and antioxidant therapies - the project will accomplish the following goals: i) To demonstrate that cells cultured under physiological levels of oxygen have a phenotype more similar to cells in vivo when compared to cells cultured under conventional conditions. ii) To determine if cells can be re-adapted to physioxia, reverting the alterations caused by years of exposure to elevated levels of oxygen. iii) To demonstrate that different panels of potential disease and therapeutical biomarkers are retrieved when cells are cultured under hyperoxia or physioxia conditions. iv) To demonstrate that biomarkers identified in physioxia conditions are more related with the ones already described in in vivo studies.