Research themes | mitochondrial research

Metabolic regulation is a key feature of all life, its deregulation leading to diabetes, cancer and neurodegenerative diseases in humans. At the cellular level, metabolism is regulated by mechanisms controlling the energy balance under changing nutrient availability. For example, a lack of nutrients triggers the activation of autophagy, which promotes the recycling of intracellular material within lysosomes, thereby providing a source of nutrient to keep the cells alive until nutrient supply is re-established. In parallel, changes in the structure of mitochondria optimize energy production. In fact, mitochondrial dynamics, the process of constant fusion and fission of mitochondria, has emerged over the last decade as an important regulator of key cellular processes such as stress responses, cellular differentiation and apoptotic cell death. For example, apoptosis requires mitochondrial fragmentation and the disruption of their internal structure (cristae). At the opposite end, we have recently shown that tightening of this internal mitochondrial structure is required to maintain cellular energy levels and viability of proliferating cells, with important implications for cancer biology. However, while mitochondrial dynamics are also clearly important in non-dividing cells such as neurons, their metabolic requirements are very different.

The main goal of our research is to understand the mechanisms linking mitochondria, autophagy and metabolism in the regulation of neuronal survival. The first major theme of my laboratory is how AMPK, a kinase regulating metabolic stress, regulates mitochondrial function. A second important theme that we study is how loss of mitochondrial function is linked to changes in autophagy and lysosomal function, all of which are altered in neurodegenerative diseases.

Marc Germain |Biography

Following his bachelor degree in biochemistry (U. Laval, 1997), Dr. Marc Germain completed is masters at Université Laval (1999) working on caspases, the apoptotic proteases. His interest for cell death then him to McGill for a Ph. D. under the supervision of Dr. Gordon Shore in the department of Biochemistry. There, he worked on the regulation of cell death and mitochondrial function by BCL-2 homologues. After completion of his PhD in 2004, he moved to UBC for a first post-doctoral fellowship, further studying the role of BCL-2 homologues in the context of apoptosis. Dr. Germain then completed second postdoctoral fellow with Dr. Ruth Slack at U. Ottawa. There, he used his extensive background in mitochondria and apoptosis to study their role in animal models of neurodegenerative diseases. Dr. Germain established his lab at UQTR in 2013 to study the mechanisms linking mitochondria, autophagy and metabolism in the regulation of cell survival.