Neural stem cells (NSC) have tremendous therapeutic potential in the repair of central nervous system injury and disease. Knowledge of NSC biology will also aid in the understanding of developmental brain disorders as well as brain tumors, which may result from abnormal NSC proliferation. A fundamental property of neural and other stem cells is their ability to undergo self-renewing proliferation. This application focuses on NSC proliferation and self-renewal and is based on our previous discovery-driven work, identifying genes enriched in neural progenitors compared to their more differentiated progeny. It is hypothesized that genes expressed in multiple stem cell populations will play important roles in NSC self-renewal. The first two aims of this proposal focus upon three genes that share the characteristics of restricted expression in CNS germinal zones and expression in multiple stem cell-containing cultures: MELK (maternal embryonic leucine zipper kinase), PSP (phosphsoserine phosphatase), and TOPK (TLAK cell originating protein kinase). Expression analysis will be performed to determine whether these genes are synthesized by multipotent, self-renewing stem cells. This will consist of standard localization methods along with study of gene-specific, promoter-driven expression of enhanced green fluorescence protein. Progenitor cells transfected with these constructs will be sorted using FACS and assayed for their ability to serve as self-renewing, multipotent stem cells. The hypothesis that MELK, TOPK and PSP regulate neural stem/progenitor self-renewal will be directly tested by determining whether knockdown and/or over expression influences self-renewal of primary progenitors. The cell cycle mechanisms underlying any changes observed will be determined using a combination of FACS analysis of DNA content, and assay of cell cycle regulatory proteins. In addition to the study of individual genes, further experiments will test broader hypotheses with respect to gene expression in self-renewing NSCs. First, the hypothesis that genes expressed in multiple stem cell populations will regulate neural stem/progenitor cell proliferation will be more generally tested using 38 genes identified in a previous study. These genes will be further stratified and then screened for function in stem cell self-renewal using primary CNS progenitors. PTEN-deficient NSC have a greater capacity for self-renewal and genes enriched in these cells will be candidates to play important roles in NSC self-renewal. In another set of experiments, microarray analysis will be used to compare gene expression in PTEN-deficient and wild type neurosphere cultures to discover genes and gene networks regulating self-renewal.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Research Project (R01)
Project #
5R01MH065756-05
Application #
6915655
Study Section
Neurogenesis and Cell Fate Study Section (NCF)
Program Officer
Sieber, Beth-Anne
Project Start
2001-09-21
Project End
2008-04-30
Budget Start
2005-05-01
Budget End
2006-04-30
Support Year
5
Fiscal Year
2005
Total Cost
$278,100
Indirect Cost
Name
University of California Los Angeles
Department
Pharmacology
Type
Schools of Medicine
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Le Belle, Janel E; Sperry, Jantzen; Ngo, Amy et al. (2014) Maternal inflammation contributes to brain overgrowth and autism-associated behaviors through altered redox signaling in stem and progenitor cells. Stem Cell Reports 3:725-34
Le Belle, Janel E; Orozco, Nicolas M; Paucar, Andres A et al. (2011) Proliferative neural stem cells have high endogenous ROS levels that regulate self-renewal and neurogenesis in a PI3K/Akt-dependant manner. Cell Stem Cell 8:59-71
Nakano, Ichiro; Kornblum, Harley I (2009) Methods for analysis of brain tumor stem cell and neural stem cell self-renewal. Methods Mol Biol 568:37-56
Wexler, Eric M; Paucer, Andres; Kornblum, Harley I et al. (2009) Endogenous Wnt signaling maintains neural progenitor cell potency. Stem Cells 27:1130-41
Kelly, Theresa K; Karsten, Stanislav L; Geschwind, Daniel H et al. (2009) Cell lineage and regional identity of cultured spinal cord neural stem cells and comparison to brain-derived neural stem cells. PLoS One 4:e4213
Gregorian, Caroline; Nakashima, Jonathan; Le Belle, Janel et al. (2009) Pten deletion in adult neural stem/progenitor cells enhances constitutive neurogenesis. J Neurosci 29:1874-86
Saxe, Jonathan P; Wu, Hao; Kelly, Theresa K et al. (2007) A phenotypic small-molecule screen identifies an orphan ligand-receptor pair that regulates neural stem cell differentiation. Chem Biol 14:1019-30
Nakano, Ichiro; Dougherty, Joseph D; Kim, Kevin et al. (2007) Phosphoserine phosphatase is expressed in the neural stem cell niche and regulates neural stem and progenitor cell proliferation. Stem Cells 25:1975-84
Imura, Tetsuya; Nakano, Ichiro; Kornblum, Harley I et al. (2006) Phenotypic and functional heterogeneity of GFAP-expressing cells in vitro: differential expression of LeX/CD15 by GFAP-expressing multipotent neural stem cells and non-neurogenic astrocytes. Glia 53:277-93
Dougherty, J D; Garcia, A D R; Nakano, I et al. (2005) PBK/TOPK, a proliferating neural progenitor-specific mitogen-activated protein kinase kinase. J Neurosci 25:10773-85

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