1. RHOA signaling defects result in impaired axon guidance in iPSC-derived neurons from patients with tuberous sclerosis complex.
- Author
-
Catlett TS, Onesto MM, McCann AJ, Rempel SK, Glass J, Franz DN, and Gómez TM
- Subjects
- Adolescent, Axon Guidance drug effects, Biopsy, CRISPR-Cas Systems, Cell Line, Ephrins pharmacology, Fluorescence Resonance Energy Transfer, Haploinsufficiency, Heterozygote, Humans, Male, Myosins metabolism, Nerve Net pathology, Neurogenesis drug effects, Neurons drug effects, Organoids cytology, Organoids metabolism, Protein Biosynthesis drug effects, Protein Biosynthesis genetics, Signal Transduction drug effects, Signal Transduction genetics, TOR Serine-Threonine Kinases metabolism, Tuberous Sclerosis genetics, Tuberous Sclerosis Complex 2 Protein genetics, Axon Guidance genetics, Induced Pluripotent Stem Cells metabolism, Nerve Net metabolism, Neurogenesis genetics, Neurons metabolism, Tuberous Sclerosis metabolism, Tuberous Sclerosis Complex 2 Protein metabolism, rhoA GTP-Binding Protein metabolism
- Abstract
Patients with Tuberous Sclerosis Complex (TSC) show aberrant wiring of neuronal connections formed during development which may contribute to symptoms of TSC, such as intellectual disabilities, autism, and epilepsy. Yet models examining the molecular basis for axonal guidance defects in developing human neurons have not been developed. Here, we generate human induced pluripotent stem cell (hiPSC) lines from a patient with TSC and genetically engineer counterparts and isogenic controls. By differentiating hiPSCs, we show that control neurons respond to canonical guidance cues as predicted. Conversely, neurons with heterozygous loss of TSC2 exhibit reduced responses to several repulsive cues and defective axon guidance. While TSC2 is a known key negative regulator of MTOR-dependent protein synthesis, we find that TSC2 signaled through MTOR-independent RHOA in growth cones. Our results suggest that neural network connectivity defects in patients with TSC may result from defects in RHOA-mediated regulation of cytoskeletal dynamics during neuronal development.
- Published
- 2021
- Full Text
- View/download PDF