Properties of neurons derived from induced pluripotent stem cells of Gaucher disease type 2 patient fibroblasts: potential role in neuropathology

Authors:
Ying Sun, Jane Florer, Christopher N. Mayhew, Zhanfeng Jia, Zhiying Zhao, Kui Xu, Huimin Ran, Benjamin Liou, Wujuan Zhang, Kenneth D. R. Setchell, Jianguo Gu, Gregory A. Grabowski
In:
Source: PLoS ONE
Publication Date: (2015)
Issue: 10(3): e0118771
Research Area:
Neurobiology
Stem Cells
Basic Research
Cells used in publication:
Fibroblast, dermal (NHDF-Neo), human neonatal
Species: human
Tissue Origin: dermal
Embryonic Stem Cell (ES), human
Species: human
Tissue Origin: embryo
Platform:
Nucleofector™ I/II/2b
Experiment

Generation of iPSC lines from control and GD2 fibroblasts: Fibroblasts were nucleofected (program U-20) with episomal plasmids pCLXE-hOct3/4-shp53, pCLXE- hSox2-Klf4, pCLXE- hLmyc-Lin28, and pCLXE-GFP. Six days post-nucleofection, fibroblasts were replated in MEF media in a gelatin-coated 10 cm dish containing 1.07E+6 irradiated mouse embryonic fibroblasts (MEFs). Starting on day 7 post-transfection, cells were fed daily with DMEM/F12 media supplemented with 20% knockout serum replacement, 1 mM L-glutamine, 0.1 mM ß-mercaptoethanol, 0.1 mM nonessential amino acids, and 4 ng/mL basic FGF. Approximately 2 weeks later, discrete colonies with hESC-like morphology were manually excised and replated in mTeSR1 media in tissue culture dishes coated with hESC-qualified matrigel. Lonza summary: This article shows a great example of generating cellular diseased models to study a genetic neuropathy. The Nucleofector device was used to reprogram patient and normal donor fibroblast into iPSC, which were in turn differentiated into neurons. This is the first study that reports abnormal electrophysiological properties in Gaucher Disease type 2 iPSC-derived neurons.

Abstract

Gaucher disease (GD) is caused by insufficient activity of acid ß-glucosidase (GCase) resulting from mutations in GBA1. To understand the pathogenesis of the neuronopathic GD, induced pluripotent stem cells (iPSCs) were generated from fibroblasts isolated from three GD type 2 (GD2) and 2 unaffected (normal and GD carrier) individuals. The iPSCs were converted to neural precursor cells (NPCs) which were further differentiated into neurons. Parental GD2 fibroblasts as well as iPSCs, NPCs, and neurons had similar degrees of GCase deficiency. Lipid analyses showed increases of glucosylsphingosine and glucosylceramide in the GD2 cells. In addition, GD2 neurons showed increased a-synuclein protein compared to control neurons. Whole cell patch-clamping of the GD2 and control iPSCs-derived neurons demonstrated excitation characteristics of neurons, but intriguingly, those from GD2 exhibited consistently less negative resting membrane potentials with various degree of reduction in action potential amplitudes, sodium and potassium currents. Culture of control neurons in the presence of the GCase inhibitor (conduritol B epoxide) recapitulated these findings, providing a functional link between decreased GCase activity in GD and abnormal neuronal electrophysiological properties. To our knowledge, this study is first to report abnormal electrophysiological properties in GD2 iPSC-derived neurons that may underlie the neuropathic phenotype in Gaucher disease.