Glycogen synthase kinase-3 inhibition promotes proliferation and neuronal differentiation of human-induced pluripotent stem cell-derived neural progenitors
Authors: Shiva Nemati
Sahar Kiani
Hossein Baharvand
Fereshteh Esfandiari
Hamid Gourabi
Ali Fathi
Journal: Stem Cells and Development (2012)
Discipline: CLINICAL MEDICINE
Keywords: hiPSC-NPs; neural progenitors; cell replacement therapy; neurological diseases; proliferation
Affiliations: Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran., Department of Developmental Biology, University of Science and Culture, ACECR, Tehran, Iran., Department of Molecular Systems Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran., Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.

Abstract:  Human-induced pluripotent stem cell-derived neural progenitors (hiPSC-NPs) have the ability to self-renew and differentiate into glial and neuronal lineages, which makes them an invaluable source in cell replacement therapy for neurological diseases. Therefore, their enhanced proliferation and neuronal differentiation are pivotal features that can be used in repairing neurological injuries. One of the main regulators of neural development is Wnt signaling, which results in the inhibition of glycogen synthase kinase 3 (GSK-3). Here, we assess the impact of GSK-3 inhibition by the small molecule CHIR99021 on the expansion and differentiation of hiPSC-NPs in an adherent condition and a defined medium. Cell proliferation analyses have revealed that inhibition of GSK-3 in the presence of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) increased the proliferation of hiPSC-NPs across 10 passages. The inhibition of β-catenin signaling by XAV and NOTCH signaling by DAPT reversed CHIR impact on hiPSC-NPs proliferation. The target genes of β-catenin, C-MYC and CYCLIN D1 as well as NOTCH target genes, HES1 and HES5 were upregulated. The treatment of NPs by CHIR in the absence of bFGF and EGF resulted in an increase of neuronal differentiation rather than proliferation by stabilization of β-catenin regardless of the NOTCH pathway. Thus, GSK-3 inhibition has been shown to promote proliferation of the NPs by activating β-catenin and NOTCH-related cell cycle genes in the presence of bFGF and EGF. Additionally, during GSK-3 inhibition, an absence of these growth factors allows for the switch to neuronal differentiation with a bias toward a dopaminergic fate. This may provide desired cells that can be used in therapeutic applications and offer insights into the etiology of some neurological disorders. 

Retracted: No

PubPeer comments:
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 Image recycling between two papers; experimental conditions and cell lines are different. doi:10.1016 j.ejpb.2007.09.008 Fig. 5. Comparison of transfection efficiency of various guanidinated PEIu2013DNA complexes. HEK 293 cells were incubated with guanidinated PEIu2013DNA complexes at various N P ratios and incubated for 48 h. The Green Fluorescent Protein (GFP) expression was observed under fluorescent microscope at 10u00b7magnification. The data were recorded at optimal transfection efficiency at the mentioned guanidinated PEI: DNA ratio. doi:10.1016 j.ijpharm.2006.12.032 Fig. 6. Comparison of transfection efficiency of various acylated PEI nanoparticle complexes. COS-1 cells were incubated with DNA-loaded acylated PEI nanoparticle complexes at various weight ratios and incubated for 4 days. The green fluorescent protein (GFP) expression was observed under fluorescent microscopeat 10u00d7 magnification. The data was recorded at optimal transfection efficiency at the mentioned acylated PEI nanoparticle:DNA ratio. ![file] , 
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