1. Purkinje cells derived from TSC patients display hypoexcitability and synaptic deficits associated with reduced FMRP levels and reversed by rapamycin
- Author
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Min-Joon Han, Deniz Cataltepe, Kellen D. Winden, Clifford J. Woolf, Daria Turner, Mustafa Sahin, Mary E. Hatten, Ville J. Kujala, David E. Buchholz, Kush Kapur, Ivan Tochitsky, and Maria Sundberg
- Subjects
0301 basic medicine ,Adult ,Cerebellum ,congenital, hereditary, and neonatal diseases and abnormalities ,Autism Spectrum Disorder ,Induced Pluripotent Stem Cells ,Cerebellar Purkinje cell ,mTORC1 ,Biology ,Mechanistic Target of Rapamycin Complex 1 ,Models, Biological ,Article ,Tuberous Sclerosis Complex 1 Protein ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,Fragile X Mental Retardation Protein ,Purkinje Cells ,Downregulation and upregulation ,Cerebellar Diseases ,Tuberous Sclerosis ,Tuberous Sclerosis Complex 2 Protein ,medicine ,Humans ,Child ,Molecular Biology ,Sirolimus ,TOR Serine-Threonine Kinases ,Tumor Suppressor Proteins ,Glutamate receptor ,nervous system diseases ,Psychiatry and Mental health ,030104 developmental biology ,medicine.anatomical_structure ,Child, Preschool ,Synapses ,Synaptophysin ,biology.protein ,Female ,TSC2 ,Neuroscience ,GRID2 - Abstract
Accumulating evidence suggests that cerebellar dysfunction early in life is associated with autism spectrum disorder (ASD), but the molecular mechanisms underlying the cerebellar deficits at the cellular level are unclear. Tuberous sclerosis complex (TSC) is a neurocutaneous disorder that often presents with ASD. Here, we developed a cerebellar Purkinje cell (PC) model of TSC with patient-derived human induced pluripotent stem cells (hiPSCs) to characterize the molecular mechanisms underlying cerebellar abnormalities in ASD and TSC. Our results show that hiPSC-derived PCs from patients with pathogenic TSC2 mutations displayed mTORC1 pathway hyperactivation, defects in neuronal differentiation and RNA regulation, hypoexcitability and reduced synaptic activity when compared with those derived from controls. Our gene expression analyses revealed downregulation of several components of fragile X mental retardation protein (FMRP) targets in TSC2-deficient hiPSC-PCs. We detected decreased expression of FMRP, glutamate receptor δ2 (GRID2), and pre- and post-synaptic markers such as synaptophysin and PSD95 in the TSC2-deficient hiPSC-PCs. The mTOR inhibitor rapamycin rescued the deficits in differentiation, synaptic dysfunction, and hypoexcitability of TSC2 mutant hiPSC-PCs in vitro. Our findings suggest that these gene expression changes and cellular abnormalities contribute to aberrant PC function during development in TSC affected individuals.
- Published
- 2018