Lisa Knaus
lisa.knaus@ist.ac.at
Supervisor: Gaia Novarino, Institute of Science and Technology Austria
Co-Supervisor: Johann Danzl, Institute of Science and Technology, Austria
Details
Start of the project: 01.08.2019
Title of the project: The role of Slc7a5 in neurodevelopment and neuronal survival
Research topic of the student: Autism spectrum disorders (ASD) represent a heterogeneous group of genetic disorders often overlapping with other neurological conditions such intellectual disability, ADHD or microcephaly. Previously, we described that the solute carrier transporter 7a5 (SLC7A5), a large neutral amino acid transporter, has a crucial role in maintaining branched chain amino acid (BCAA) levels in the brain [1]. We identified several patients harboring a homozygous missense mutation in the SLC7A5 gene, who are on the autism spectrum (ASD) and are presented with motor deficits and microcephaly. In Mice, deletion of Slc7a5 from the blood brain barrier endothelial cells leads to decreased levels of BCAAs in the brain, altered cap-dependent translation and severe neurological abnormalities on an electrophysiological and behavioral level. Intracerebroventricular administration of BCAAs partially ameliorated the neurological impairments in adult mutant mice. Now, aiming to dissect the molecular mechanisms underlying the microcephalic phenotype of the patients, we generated conditional knock-out mouse lines (cKO) of Slc7a5 specifically targeting neuroprogenitor cells of the developing brain. These cKO mice are presented with a microcephalic brain, thereby recapitulating the patient’s phenotype. Our recent findings imply that the significant reduction of cortical thickness is caused by an induction of apoptosis within the postnatal cortex affecting mainly upper layer neurons. This indicates a crucial role of Slc7a5 not only in regulating branched chain amino acid levels in the brain, but also for neuronal survival. Thereby, introducing Slc7a5 as a potential drug target for modulating neuronal survival within a pathophysiological context.
[1] Tarlungeanu, D.C., Deliu, E., Dotter, C.P., et al. 2016. Impaired Amino Acid Transport at the Blood Brain Barrier Is a Cause of Autism Spectrum Disorder. Cell 167(6), 1481-1494.
Lab Rotation project: 15.12.2019-15.02.2020 (8-9 weeks)
Project titles: Project I: Imaging newly synthesized proteins
Project II: Imaging ribosomal RNA
Lab Host: Johann DANZL, IST