HIGH CONTENT QUANTITATIVE FRAMEWORK FOR UNDERSTANDING MITOCHONDRIAL DYSFUNCTION IN HUMAN CELLS

Abstract

Cellular and systemic stress disrupt function and impact health. This multidisciplinary thesis investigates the effects of internal and external stress in two contexts, mitochondrial dysfunction in Huntington Disease (HD) and publication pressure experienced by Canadian researchers during the COVID-19 pandemic. Standardized tools for accurately quantifying mitochondrial morphology remain limited, despite recent interest in understanding the role of mitochondrial dysfunction in HD. We first developed a high content and semi-automated analysis system for assessing mitochondrial morphology in patient-derived human fibroblasts. We compared control and HD cells, where HD fibroblasts were highly fragmented, and carried out orthogonal assays to measure energy production and mitochondrial membrane potential, validating the morphological results. We next evaluated how mitochondrial morphology responds to various stressors, including DNA damage, mitochondrial toxins, and nutrient and metabolite deprivation. The difference in the morphological response between control and diseased cells provided mechanistic insight into mitochondrial dysfunction in HD. Shifting focus to another form of stress, we also measured academic pressure during the COVID-19 pandemic. We explored disparities in perceived publication pressure reported between various populations, such as gender and disability status, using a nationwide survey of Canadian researchers. This thesis offers a dual biological and academic perspective on stress in the context of adaptation and resilience. Our interdisciplinary approach provides novel insights into mitochondrial morphology in HD and contributes to ongoing discussions about sustainable research cultures.