@article{77bbd63d7d744ce891ce24ae24bc875c,
title = "Cell-type-specific profiling of human cellular models of fragile X syndrome reveal PI3K-dependent defects in translation and neurogenesis",
abstract = "Transcriptional silencing of the FMR1 gene in fragile X syndrome (FXS) leads to the loss of the RNA-binding protein FMRP. In addition to regulating mRNA translation and protein synthesis, emerging evidence suggests that FMRP acts to coordinate proliferation and differentiation during early neural development. However, whether loss of FMRP-mediated translational control is related to impaired cell fate specification in the developing human brain remains unknown. Here, we use human patient induced pluripotent stem cell (iPSC)-derived neural progenitor cells and organoids to model neurogenesis in FXS. We developed a high-throughput, in vitro assay that allows for the simultaneous quantification of protein synthesis and proliferation within defined neural subpopulations. We demonstrate that abnormal protein synthesis in FXS is coupled to altered cellular decisions to favor proliferative over neurogenic cell fates during early development. Furthermore, pharmacologic inhibition of elevated phosphoinositide 3-kinase (PI3K) signaling corrects both excess protein synthesis and cell proliferation in a subset of patient neural cells.",
keywords = "FMRP, Fragile X syndrome, autism, flow cytometry, iPSCs, neural stem cells, neurogenesis, protein synthesis, translation",
author = "Nisha Raj and McEachin, {Zachary T.} and William Harousseau and Ying Zhou and Feiran Zhang and Merritt-Garza, {Megan E.} and Taliaferro, {J. Matthew} and Magdalena Kalinowska and Marro, {Samuele G.} and Hales, {Chadwick M.} and Elizabeth Berry-Kravis and Wolf-Ochoa, {Marisol W.} and Veronica Martinez-Cerde{\~n}o and Marius Wernig and Lu Chen and Eric Klann and Warren, {Stephen T.} and Peng Jin and Zhexing Wen and Bassell, {Gary J.}",
note = "Funding Information: We are extremely grateful to the patients and their families for participating in this study. We thank Christina Gross and Joel Richter for helpful discussions, Joseph Cubells (Emory University) for providing access to patient samples and clinical information, and Alysson Muotri (UCSD), Cleber Trujillo (UCSD), and Eric Wang (University of Florida) for technical support. This work was largely supported by a NICHD Fragile X Center project grant 1U54HD082013-01 (G.J.B) and, more recently, by 1P50HD104458 (G.J.B). This research project was supported in part by the Emory University Integrated Cellular Imaging Microscopy Core. C.M.H was supported by a National Institute of Neurological Disorders and Stroke award ( K08-NS087121 ). J.M.T was supported by the RNA Bioscience Initiative at the University of Colorado Anschutz Medical Campus and the Webb-Waring Early Career Investigator Award from the Boettcher Foundation ( AWD-182937 ). Funding Information: We are extremely grateful to the patients and their families for participating in this study. We thank Christina Gross and Joel Richter for helpful discussions, Joseph Cubells (Emory University) for providing access to patient samples and clinical information, and Alysson Muotri (UCSD), Cleber Trujillo (UCSD), and Eric Wang (University of Florida) for technical support. This work was largely supported by a NICHD Fragile X Center project grant 1U54HD082013-01 (G.J.B) and, more recently, by 1P50HD104458 (G.J.B). This research project was supported in part by the Emory University Integrated Cellular Imaging Microscopy Core. C.M.H was supported by a National Institute of Neurological Disorders and Stroke award (K08-NS087121). J.M.T was supported by the RNA Bioscience Initiative at the University of Colorado Anschutz Medical Campus and the Webb-Waring Early Career Investigator Award from the Boettcher Foundation (AWD-182937). N.R. and G.J.B. conceived and coordinated the project. N.R. and G.J.B. designed experiments. N.R. designed and optimized the neurOMIP assay. N.R. generated and characterized the iPSC cells; performed the iPSC differentiations into NPCs, neurons, and organoids; prepared protein lysates; conducted protein synthesis assays; conducted flow cytometry assays; and performed cell cycle assays, western blots, qPCR, immunofluorescence staining, and all relevant data analysis. J.M.T. and F.Z. generated cDNA libraries, performed RNA-seq, and analyzed RNA-seq data. N.R. Z.T.M. M.E.M.-G. performed cell cultures. Y.Z. and Z.W. performed IF analysis of organoids. M.K. performed FGF stimulation experiments in NPCs with oversight from E.K. Isogenic iPSC and ESC lines were generated and/or provided by M.W. L.C. S.G.M. and S.T.W. and C.M.H.; and E.B.-K. provided control and patient fibroblast samples and associated clinical data. V.M.-C. M.W. and W.W.-O. provided human postmortem tissue and associated clinical data. N.R. wrote the manuscript. N.R. G.J.B. Z.T.M. P.J. and S.T.W. revised and edited the manuscript. G.J.B. supervised the overall project and provided funding and resources. The authors declare no competing interests. Publisher Copyright: {\textcopyright} 2021 The Author(s)",
year = "2021",
month = apr,
day = "13",
doi = "10.1016/j.celrep.2021.108991",
language = "English (US)",
volume = "35",
journal = "Cell Reports",
issn = "2211-1247",
publisher = "Cell Press",
number = "2",
}