Authors :
Presenting Author: Caroline Pearson, PhD – Weill Cornell Medicine
Catherine Dyevich, Bachelors – Research Tecnician, Brain and Mind Research Institute, Weill Cornell Medicine; Alexandra Rubin, NA – Brain and Mind Research Institute – Weill Cornell Medicine; Shawn Singh, Bachelors – Brain and Mind Research Institute – Weill Cornell Medicine; M. Elizabeth Ross, MD, PhD – Brain and Mind Research Institute – Weill Cornell Medicine
Rationale:
GLUT1-deficiency syndrome (GLUT1-DS) causes impaired transport of glucose across the blood brain barrier, resulting in a spectrum of neurological conditions, including infantile seizures, postnatal microcephaly, developmental delay, spasticity, ataxia and intellectual disability. There are currently no effective treatments. We have demonstrated that Glut1 is expressed during cortical development in neural progenitor cells (NPCs) in both the mouse and human.
Conditional loss of Glut1 in cortical NPCs results in a significant tangential expansion of the cortex and increased self-renewing divisions. These changes are associated with an increased oxygen consumption and dependence on ATP generation through the TCA cycle. Early changes in development have an impact upon the neuronal composition of the cortex thus raising the possibility that pathologies associated with GLUT1-DS are in part due to reduced glucose uptake by NPCs during brain development. Our aim is to determine the role of Glut1 in NPCs during mouse and human brain development and assess whether the loss of GLUT1 contributes to brain defects associated with GLUT1-DS.
Methods:
Conditional mouse mutants in which Glut1 is removed from cortical NPCs are used to assess the impact of impaired glucose uptake on neural progenitor populations. We use a combination of techniques, including immunohistochemistry and proliferation assays to quantify the impact of Glut1 deficiency on NPC identity, proliferation, division angle, and fate. In tandem, we are assessing how the loss of Glut1 in NPCs impacts
metabolism using oxygen consumption and extracellular acidification assays, mass spectrometry, and MALDI spatial metabolomics. We are developing a human model of GLUT1-DS using 3D neural organoids derived from GLUT1 homozygous and heterozygous and patient derived induced pluripotent stem cells (iPSCs). We are determining the impact of GLUT deficiency on cortical populations using a combination of immunohistochemical techniques and transcriptional profiling. Metabolomic studies include Seahorse assays, and mass spectrometry. Furthermore, we are assessing the impact of GLUT1 loss on neuronal activity using Multi electrode array.
Results:
Loss of Glut1 in mouse NPCs results in early developmental phenotypes including tangential expansion of the cortex and increased progenitor cell populations. These early effects are associated with increased reliance on TCA-cycle/Oxidative phosphorylation for energy production. Early changes in NPC proliferation result in changes in neuronal differentiation and specification. We have generated GLUT1 homozygous and heterozygous iPSCs to establish a model of human brain development and GLUT1-DS in 3D neural organoids.
Conclusions:
Using a combination of mouse and human models, we are beginning to elucidate the role of glucose transport and metabolism during brain development. By developing an in vitro model of GLUT1-DS we aim to further elucidate the etiology of GLUT1-DS and establish a platform to identify novel therapeutic targets for GLUT1-DS individuals. Funding: Brain and Spine Institute, New York Presbyterian Hospital and Weill Cornell Medicine
Glut1 Deficiency Foundation