Determining the Role of Glucose Transporter 1 in Neural Development and Disease - PROJECT SUMMARY Glucose homeostasis is critical during embryogenesis; fetal hyper- or hypoglycemia can cause neurodevelopmental disorders, including impaired neurulation, altered brain growth, epilepsy, Autism, and Attention Deficit Disorder. GLUT1-Deficiency Syndrome (GLUT1-DS) causes a variety of neurological disorders, including infantile seizures, developmental delay, postnatal microcephaly, and intellectual disability. To better understand the role of Glut1 during cortical development and the contribution of neural progenitor cell (NPC)- specific GLUT1 loss to GLUT1-DS, we aim to determine how NPCs regulate glucose uptake during neurogenesis and how glucose metabolism influences NPC self-renewal and cell fate decisions. Our preliminary data make us hypothesize that 1) Glut1 expression in cortical NPCs (termed radial glia; RG) regulates glucose uptake and metabolism dynamics throughout neurogenesis to direct cell fate decisions. 2) During human development, early changes in RG proliferation due to a reduction in GLUT1 expression impact neurogenesis and contribute to the etiology of GLUT1-DS. To test these hypotheses, we will pursue two parallel aims in mouse and human models of cortical development. Aim 1 will explore the function of Glut1 in RG during mouse corticogenesis. We will conditionally remove Glut1 from RG and determine the impact on proliferation, cell cycle dynamics and differentiation using a combination of approaches including immunohistochemistry, single cell transcriptomics, and fluorescent in situ hybridization. We will assess the metabolomic changes associated with loss of Glut1 through metabolic flux and proteomic assays. Aim 2 will use cerebral organoids generated from human pluripotent stem cells harboring GLUT1 mutations and examine the impact on cortical differentiation and neuronal function. Using a cerebral organoid model will enable us to explore the neural contribution to GLUT1- DS and potential evolutionary differences between progenitor metabolism in mouse and humans. Experiments will combine cutting edge technologies to determine the link between RG metabolism and cell fate decisions using in vivo and in vitro metabolomic assays along with single-cell transcriptomic and imaging methods. Pursuing these aims will open new avenues of inquiry into the metabolic regulation of RG fate and differentiation in health and disease. Our long-term objective is to understand the combinatorial actions of environmental and genetic factors during cortical development and identify potential therapeutic pathways.
