Abstract

This Project will define the mechanisms by which human embryonic stem cell (hESC) self-renewal ispreserved and how early differentiation decisions are made.These studies focus on the role of PI3K in promoting GSK3-beta activity, a point of regulation that is criticalfor blocking an epithelial to mesenchymal transition (EMT) and differentiation towards mesendoderm. Controlof mesendoderm development, following loss of PI3K and GSK3-beta activity, is not well understood. Toaddress this issue, respective roles for Wnt and TGF-beta family members in mesendoderm specification willbe defined. Understanding these issues is critical not only in relation to hESC self-renewal, but also forunderstanding the basic mechanisms underpinning early cell fate decisions, including definitive endodermand mesoderm specification from a mesendoderm precursor.
The first Aim of this Project will investigate the role of GSK3-beta in control of EMTs and how it regulates theactivity of two transcription factors, Snail 1 and beta-catenin. Mechanisms by which these transcription factorscontrol EMTs will be defined.
The second Aim will investigate the signaling pathways required for hESC self-renewal and specifically, howPI3K maintains GSK3-beta activity and inhibits an EMT.
The third Aim, will establish the exact conditions for early cell fate commitment to mesendoderm and howWnt and TGF-beta synergize to pattern this cell type. Finally, we will investigate the use of GSK3-betainhibitors as compounds that can promote uniform differentiation of hESCs.Understanding the mechanisms of hESC self-renewal is critical if we are to harness their full potential as adevelopmental model and as a therapeutic source of cells that can be used in regenerative medicine. Ourunderstanding of hESC differentiation into different lineages is only poorly understood. This proposal willfocus on a very early stage of cell fate commitment that is critical for differentiation into two key lineages.First, mesoderm which can give rise to blood, muscle and bone. Second, definitive endoderm which givesrise to pancreas, liver, lung, intestine and thyroid.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Program Projects (P01)
Project #
1P01GM085354-01
Application #
7538027
Study Section
Special Emphasis Panel (ZGM1-GDB-8 (SC))
Project Start
Project End
Budget Start
2008-08-01
Budget End
2009-07-31
Support Year
1
Fiscal Year
2008
Total Cost
$339,250
Indirect Cost

  Institution

Name
University of Georgia
Department
Type
DUNS #
004315578
City
Athens
State
GA
Country
United States
Zip Code
30602

  Publications

Sima, Jiao; Bartlett, Daniel A; Gordon, Molly R et al. (2018) Bacterial artificial chromosomes establish replication timing and sub-nuclear compartment de novo as extra-chromosomal vectors. Nucleic Acids Res 46:1810-1820
Singh, Amar M; Dalton, Stephen (2018) What Can 'Brown-ing' Do For You? Trends Endocrinol Metab 29:349-359
Dixon, Jesse R; Xu, Jie; Dileep, Vishnu et al. (2018) Integrative detection and analysis of structural variation in cancer genomes. Nat Genet 50:1388-1398
Xu, Chenhuan; Corces, Victor G (2018) Genome-Wide Mapping of Protein-DNA Interactions on Nascent Chromatin. Methods Mol Biol 1766:231-238
Dileep, Vishnu; Gilbert, David M (2018) Single-cell replication profiling to measure stochastic variation in mammalian replication timing. Nat Commun 9:427
Colunga, Thomas; Dalton, Stephen (2018) Building Blood Vessels with Vascular Progenitor Cells. Trends Mol Med 24:630-641
Wang, Tao; Holt, Matthew V; Young, Nicolas L (2018) The histone H4 proteoform dynamics in response to SUV4-20 inhibition reveals single molecule mechanisms of inhibitor resistance. Epigenetics Chromatin 11:29
Xu, Chenhuan; Corces, Victor G (2018) Nascent DNA methylome mapping reveals inheritance of hemimethylation at CTCF/cohesin sites. Science 359:1166-1170
Marchal, Claire; Sasaki, Takayo; Vera, Daniel et al. (2018) Genome-wide analysis of replication timing by next-generation sequencing with E/L Repli-seq. Nat Protoc 13:819-839
Rivera-Mulia, Juan Carlos; Schwerer, Hélène; Besnard, Emilie et al. (2018) Cellular senescence induces replication stress with almost no affect on DNA replication timing. Cell Cycle 17:1667-1681

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