Embryonic stem (ES) cells isolated from the inner cell mass of murine blostocysts are pluripotent, capable of indefinite symmetric cell division, and can generate chimeric animals. The recent isolation of human ES cells holds great promise for the treatment of a variety of degenerative disorders including, but not limited to, Parkinson's disease and diabetes. The homeodomain transcription factors, Oct3/4 and Nanog, are believed to play critical roles in sustaining ES cell pluripotency. Surprisingly, targets of Nanog are completely unknown and few Oct3/4 targets have been proposed. Thus, the molecular mechanisms that repress differentiation of ES cells and promote self-renewal are poorly defined. We have developed a novel approach for identifying complex metazoan regulons called SACO (Serial Analysis of Chromatin Occupancy), which combines chromatin immunoprecipitation with a modification of Long SAGE. We will use SACO to identify the entire complement of Nanog and Oct3/4 genomic targets in mouse ES cells. Such knowledge would not only aid efforts to characterize mechanisms that govern cell-fate commitment of stem cells, but could also enable the indefinite propagation of existing human stem cell lines. Insight into these transcriptional networks could also lead to the generation of pluripotent stem cells from adult tissues or cells. Our studies are designed to provide a complete definition of Nanog and Oct3/4 targets in pluripotent stem cells. By characterizing the regulation of the corresponding transcripts, we expect to characterize the molecular pathways that control self-renewal and pluripotency of ES cells. The microarrays representing novel Nanog and Oct3/4 driven transcripts and the catalog of genomic binding sites will be provided to the stem cell research community. The creation of microarrays representing novel Nanog and Oct3/4 targets will facilitate high-throughput analysis of their expression during early embryogenesis and their regulation by pathways that regulate differentiation and pluripotency. This set of studies will represent the most comprehensive analysis to date of the regulation of transcription factor binding in any metazoan system. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM074788-02
Application #
7248722
Study Section
Development - 2 Study Section (DEV2)
Program Officer
Zatz, Marion M
Project Start
2006-07-01
Project End
2011-06-30
Budget Start
2007-07-01
Budget End
2008-06-30
Support Year
2
Fiscal Year
2007
Total Cost
$284,115
Indirect Cost
Name
Oregon Health and Science University
Department
Neurosciences
Type
Schools of Medicine
DUNS #
096997515
City
Portland
State
OR
Country
United States
Zip Code
97239
Impey, Soren; Davare, Monika; Lesiak, Adam et al. (2010) An activity-induced microRNA controls dendritic spine formation by regulating Rac1-PAK signaling. Mol Cell Neurosci 43:146-56