title: EZH2 regulates neuronal differentiation of mesenchymal stem cells through PIP5K1C-dependent calcium signaling.
abstract: Enhancer of zeste homolog 2 (EZH2) regulates stem cells renewal, maintenance, and differentiation into different cell lineages including neuron. Changes in intracellular Ca(2+) concentration play a critical role in the differentiation of neurons. However, whether EZH2 modulates intracellular Ca(2+) signaling in regulating neuronal differentiation from human mesenchymal stem cells (hMSCs) still remains unclear. When hMSCs were treated with a Ca(2+) chelator or a PLC inhibitor to block IP(3)-mediated Ca(2+) signaling, neuronal differentiation was disrupted. EZH2 bound to the promoter region of PIP5K1C to suppress its transcription in proliferating hMSCs. Interestingly, knockdown of EZH2 enhanced the expression of PIP5K1C, which in turn increased the amount of PI(4,5)P(2), a precursor of IP(3), and resulted in increasing the intracellular Ca(2+) level, suggesting that EZH2 negatively regulates intracellular Ca(2+) through suppression of PIP5K1C. Knockdown of EZH2 also enhanced hMSCs differentiation into functional neuron both in vitro and in vivo. In contrast, knockdown of PIP5K1C significantly reduced PI(4,5)P(2) contents and intracellular Ca(2+) release in EZH2-silenced cells and resulted in the disruption of neuronal differentiation from hMSCs. Here, we provide the first evidence to demonstrate that after induction to neuronal differentiation, decreased EZH2 activates the expression of PIP5K1C to evoke intracellular Ca(2+) signaling, which leads hMSCs to differentiate into functional neuron lineage. Activation of intracellular Ca(2+) signaling by repressing or knocking down EZH2 might be a potential strategy to promote neuronal differentiation from hMSCs for application to neurological dysfunction diseases.
authors.affiliation: Center for Molecular Medicine, China Medical University Hospital, Taichung 404, Taiwan. ylyu@mail.cmu.edu.tw
authors.forename: Yung-Luen
authors.initials: YL
authors.lastname: Yu
authors.forename: Ruey-Hwang
authors.initials: RH
authors.lastname: Chou
authors.forename: Ling-Tzu
authors.initials: LT
authors.lastname: Chen
authors.forename: Woei-Cherng
authors.initials: WC
authors.lastname: Shyu
authors.forename: Su-Ching
authors.initials: SC
authors.lastname: Hsieh
authors.forename: Chen-Shiou
authors.initials: CS
authors.lastname: Wu
authors.forename: Hong-Jie
authors.initials: HJ
authors.lastname: Zeng
authors.forename: Su-Peng
authors.initials: SP
authors.lastname: Yeh
authors.forename: De-Ming
authors.initials: DM
authors.lastname: Yang
authors.forename: Shih-Chieh
authors.initials: SC
authors.lastname: Hung
authors.forename: Mien-Chie
authors.initials: MC
authors.lastname: Hung
mesh_terms: D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D000071221:Enhancer of Zeste Homolog 2 Protein; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology; D055785:Gene Knockdown Techniques; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D009422:Nervous System Diseases / Q000235:genetics / Q000378:metabolism / Q000628:therapy; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000096:biosynthesis* / Q000235:genetics; D063151:Polycomb Repressive Complex 2; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D002614:Chelating Agents; D004268:DNA-Binding Proteins; D014157:Transcription Factors; C498409:EZH2 protein, human; D000071221:Enhancer of Zeste Homolog 2 Protein; D063151:Polycomb Repressive Complex 2; D017853:Phosphotransferases (Alcohol Group Acceptor); C020077:1-phosphatidylinositol-4-phosphate 5-kinase; D002118:Calcium