Welcome to Minerva Special Seminar 2.12.2025 at 10:00
Dr. Merja Joensuu
PhD, MSc, BSc, MLT
Senior Research Fellow | Group Leader
Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Australia
Title: Endogenous Fatty Acid Metabolism: A New Paradigm in Brain Energy, Memory and Therapeutics
Hoast: Pirta Hotulainen, pirta.hotulainen@helsinki.fi
Abstract: Although the brain makes up only ~2% of body weight, it consumes ~20% of the body’s energy, mainly to fuel neuronal communication. Although fatty acids support mitochondrial ATP production in most tissues, neurons are believed to rely exclusively on glucose for energy. My laboratory’s recent discoveries challenge this long-standing view by demonstrating that endogenous saturated free fatty acids (sFFAs) are a major energy source for neurons. The lipid-modifying enzyme Ddhd2 releases long-chain sFFAs, notably myristic, palmitic, and stearic acids, to fuel the energy essential for neuronal communication and memory formation. My team found that loss of Ddhd2, which causes childhood-onset hereditary spastic paraplegia type 54 (HSP54) marked by progressive motor and cognitive decline, leads to neuronal energy failure and complex neuropathology. By identifying the sFFA metabolic fingerprint in Ddhd2 knockout mouse brains, we revealed that supplementing neurons with coenzyme A-conjugated sFFAs-CoA in combination reflecting their physiological ratios, restored not only the energy levels, but reversed all major HSP54 neuropathologies in vitro. This suggests that coordinated sFFA flux is essential to brain function – likely through both energetic and non-energetic roles.
Bio: Dr Merja Joensuu completed her PhD at the Institute of Biotechnology, University of Helsinki in 2014 at Eija Jokitalo’s laboratory. Followed by a joint postdoctoral training at Queensland Brain Institute, The University of Queensland (UQ) Australia and Minerva Minerva Foundation Institute for Medical Research in Pirta Hotulainen’s laboratory, she became a junior group leader in 2022, and was promoted to an independent group leader position at the Australian Institute for Bioengineering and Nanotechnology, UQ, in 2025, where her team investigates how proteins and lipids shape human health and disease. Using advanced imaging, her research aims to uncover how essential cellular processes are maintained in healthy neurons, how they are disrupted in neurological diseases or exploited by neurotoxins and viruses — with the ultimate goal of identifying novel therapeutic strategies. Currently, her lab is particularly focused on the adaptability of neuronal energy metabolism and its role in supporting neuronal function. She has received several competitive fellowships, funding and awards, including Research Council of Finland Postdoctoral Fellowship (2016–2019), and Australian Research Council Discovery Early Career Researcher Award (2019–2021), EU Horizon-National Health and Medical Research Council (NHMRC) partnership funding (2025-2028) and 2025 Queensland Young Tall Poppy Award from the Australian Institute of Policy and Science.
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