Synthetic mRNAs Drive Highly Efficient iPS Cell Differentiation to Dopaminergic Neurons

• Published in: Stem cells translational medicine 2019-02, Vol.8 (2), p.112-123
• Main Authors: Xue, Yingchao, Zhan, Xiping, Sun, Shisheng, Karuppagounder, Senthilkumar S., Xia, Shuli, Dawson, Valina L., Dawson, Ted M., Laterra, John, Zhang, Jianmin, Ying, Mingyao
• Format: Article
• Language: English
• Subjects: Animals; Bradykinin; Bradykinin - pharmacology; Cell differentiation; Cell Differentiation - drug effects; Cell Differentiation - physiology; Cells, Cultured; Chemical compounds; Chromosomes; Coding; DNA binding proteins; Dopamine - metabolism; Dopamine receptors; Dopaminergic neuron; Dopaminergic Neurons - cytology; Dopaminergic Neurons - drug effects; Dopaminergic Neurons - metabolism; Fibroblasts; Genomes; Heterocyclic Compounds, 4 or More Rings - pharmacology; Humans; Immunoglobulins; Induced pluripotent stem cell; Induced Pluripotent Stem Cells - cytology; Induced Pluripotent Stem Cells - drug effects; Induced Pluripotent Stem Cells - metabolism; Inhibitory postsynaptic potentials; Math1 protein; Medicine; Mesencephalon; Messenger RNA; Mice; Motor protein; Movement disorders; Myosin; Neurodegenerative diseases; Neurogenesis; Neurons; Parkinson Disease - metabolism; Parkinson Disease - pathology; Parkinson's disease; Pluripotency; Pluripotent Stem Cells; Pluripotent Stem Cells - cytology; Pluripotent Stem Cells - drug effects; Pluripotent Stem Cells - metabolism; Proneural transcription factor; Protein binding; Protein phosphorylation; Proteins; Proteomics; Proteomics - methods; RNA, Messenger - metabolism; Scientific equipment and supplies industry; Stem cells; Transcription factors; Transcription, Genetic - drug effects; Transcription, Genetic - physiology; Transplantation
• ISSN: 2157-6564; 2157-6580; 2157-6580
• DOI: 10.1002/sctm.18-0036

Proneural transcription factors (TFs) drive highly efficient differentiation of pluripotent stem cells to lineage‐specific neurons. However, current strategies mainly rely on genome‐integrating viruses. Here, we used synthetic mRNAs coding two proneural TFs (Atoh1 and Ngn2) to differentiate induced pluripotent stem cells (iPSCs) into midbrain dopaminergic (mDA) neurons. mRNAs coding Atoh1 and Ngn2 with defined phosphosite modifications led to higher and more stable protein expression, and induced more efficient neuron conversion, as compared to mRNAs coding wild‐type proteins. Using these two modified mRNAs with morphogens, we established a 5‐day protocol that can rapidly generate mDA neurons with >90% purity from normal and Parkinson's disease iPSCs. After in vitro maturation, these mRNA‐induced mDA (miDA) neurons recapitulate key biochemical and electrophysiological features of primary mDA neurons and can provide high‐content neuron cultures for drug discovery. Proteomic analysis of Atoh1‐binding proteins identified the nonmuscle myosin II (NM‐II) complex as a new binding partner of nuclear Atoh1. The NM‐II complex, commonly known as an ATP‐dependent molecular motor, binds more strongly to phosphosite‐modified Atoh1 than the wild type. Blebbistatin, an NM‐II complex antagonist, and bradykinin, an NM‐II complex agonist, inhibited and promoted, respectively, the transcriptional activity of Atoh1 and the efficiency of miDA neuron generation. These findings established the first mRNA‐driven strategy for efficient iPSC differentiation to mDA neurons. We further identified the NM‐II complex as a positive modulator of Atoh1‐driven neuron differentiation. The methodology described here will facilitate the development of mRNA‐driven differentiation strategies for generating iPSC‐derived progenies widely applicable to disease modeling and cell replacement therapy. Stem Cells Translational Medicine 2019;8:112&12 mRNAs coding the proneural transcription factors (Atoh1 and Ngn2) drive highly efficient differentiation of human iPS cells into midbrain dopaminergic neurons. The proneural activity of Atoh1 is modulated by the NM‐II motor protein complex.