Dr Tara Walker - QBI : "Selenium mediates exercise-induced adult neurogenesis and reverses learning deficits induced by hippocampal injury and ageing"

Speaker:

Dr Tara Walker
Queensland Brain Institute
University of Queensland

Title: Selenium mediates exercise-induced adult neurogenesis and reverses learning deficits induced by hippocampal injury and ageing

Although the neurogenesis-enhancing effects of exercise have been extensively studied, the molecular mechanisms underlying this response remain unclear. We have recently shown that this is mediated by the exercise-induced release of systemic factors including the platelet-released factor, platelet factor 4 (PF4) and the antioxidant selenium transport protein, selenoprotein P (SEPP1). This presentation will focus primarily on the latter.

Using knockout mouse models, we confirmed that SEPP1 and its receptor low-density lipoprotein receptor-related protein 8 (LRP8) are required for the exercise-induced increase in adult hippocampal neurogenesis. Moreover, we found that in vivo selenium infusion increased hippocampal neural precursor cell (NPC) proliferation and adult neurogenesis. Mimicking the effect of exercise through dietary selenium supplementation restored neurogenesis and reversed the cognitive decline associated with ageing and hippocampal injury, suggesting potential therapeutic relevance.

The focus of our current research is to further elucidate the mechanism by which selenium is exerting its neurogenesis-enhancing effect. Selenium has recently been shown to regulate ferroptosis-mediated cell death via the selenoprotein glutathione peroxidase 4 in other neural cell types. We hypothesise that a selenium-mediated reduction in ferroptotic cell death of NPCs underlies the exercise-induced increase in adult neurogenesis and cognitive function.