title: Canonical microRNAs Enable Differentiation, Protect Against DNA Damage, and Promote Cholesterol Biosynthesis in Neural Stem Cells.
abstract: Neural stem cells (NSCs) have the capacity to differentiate into neurons, astrocytes, and oligodendrocytes, and therefore represent a promising donor tissue source for treating neurodegenerative diseases and repairing injuries of the nervous system. However, it remains unclear how canonical microRNAs (miRNAs), the subset of miRNAs requiring the Drosha-Dgcr8 microprocessor and the type III RNase Dicer for biogenesis, regulate NSCs. In this study, we established and characterized Dgcr8-/-NSCs from conditionally Dgcr8-disrupted mouse embryonic brain. RNA-seq analysis demonstrated that disruption of Dgcr8 in NSCs causes a complete loss of canonical miRNAs and an accumulation of pri-miRNAs. Dgcr8-/-NSCs can be stably propagated in vitro, but progress through the cell cycle at reduced rates. When induced for differentiation, Dgcr8-/-NSCs failed to differentiate into neurons, astrocytes, or oligodendrocytes under permissive conditions. Compared to Dgcr8+/-NSCs, Dgcr8-/-NSCs exhibit significantly increased DNA damage. Comparative RNA-seq analysis and gene set enrichment analysis (GSEA) revealed that Dgcr8-/-NSCs significantly downregulate genes associated with neuronal differentiation, cell cycle progression, DNA replication, protein translation, and DNA damage repair. Furthermore, we discovered that Dgcr8-/-NSCs significantly downregulate genes responsible for cholesterol biosynthesis and demonstrated that Dgcr8-/-NSCs contain lower levels of cholesterol. Together, our data demonstrate that canonical miRNAs play essential roles in enabling lineage specification, protecting DNA against damage, and promoting cholesterol biosynthesis in NSCs.
authors.affiliation: 1 Department of Biochemistry and Molecular Genetics, Stem Cell Institute, University of Alabama at Birmingham , Birmingham, Alabama.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Liu
authors.affiliation: 2 Department of Molecular Pharmacology and Experimental Therapeutics, Center for Individualized Medicine , Mayo Clinic College of Medicine, Rochester, Minnesota.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: 1 Department of Biochemistry and Molecular Genetics, Stem Cell Institute, University of Alabama at Birmingham , Birmingham, Alabama.
authors.forename: Alireza
authors.initials: A
authors.lastname: Khodadadi-Jamayran
authors.affiliation: 3 Cancer Biology and Genetics Program, Center for Cell Engineering, Center for Stem Cell Biology, Sloan-Kettering Institute, Cell and Developmental Biology Program, Weill Medical College of Cornell University , New York, New York.
authors.forename: Lam
authors.initials: L
authors.lastname: Dang
authors.affiliation: 4 Department of Neurology, University of Alabama at Birmingham , Birmingham, Alabama.
authors.forename: Xiaosi
authors.initials: X
authors.lastname: Han
authors.affiliation: 3 Cancer Biology and Genetics Program, Center for Cell Engineering, Center for Stem Cell Biology, Sloan-Kettering Institute, Cell and Developmental Biology Program, Weill Medical College of Cornell University , New York, New York.
authors.forename: Kitai
authors.initials: K
authors.lastname: Kim
authors.affiliation: 2 Department of Molecular Pharmacology and Experimental Therapeutics, Center for Individualized Medicine , Mayo Clinic College of Medicine, Rochester, Minnesota.
authors.forename: Hu
authors.initials: H
authors.lastname: Li
authors.affiliation: 1 Department of Biochemistry and Molecular Genetics, Stem Cell Institute, University of Alabama at Birmingham , Birmingham, Alabama.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhao
mesh_terms: D000818:Animals; D001921:Brain / Q000196:embryology / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics*; D019070:Cell Lineage / Q000235:genetics; D049109:Cell Proliferation; D002784:Cholesterol / Q000096:biosynthesis*; D004249:DNA Damage / Q000235:genetics*; D015536:Down-Regulation / Q000235:genetics; D020869:Gene Expression Profiling; D051379:Mice; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D058953:Neural Stem Cells / Q000166:cytology* / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism; D017423:Sequence Analysis, RNA
chemical_list: C474044:Dgcr8 protein, mouse; D035683:MicroRNAs; D016601:RNA-Binding Proteins; D002784:Cholesterol
keywords: Dgcr8; cholesterol; miRNA; neural stem cells