SOX9 is required for maintenance of the pancreatic progenitor cell pool.
The factors necessary to maintain organ-specific progenitor cells are poorly understood and yet of extreme clinical importance. Here, we identify the transcription factor SOX9 as the first specific marker and maintenance factor of multipotential progenitors during pancreas organogenesis. In the developing pancreas, SOX9 expression is restricted to a mitotically active, Notch-responsive subset of PDX1(+) pluripotent progenitors and is absent from committed endocrine precursors or differentiated cells. Similar to Notch mutations, organ-specific Sox9 inactivation in mice causes severe pancreatic hypoplasia resulting from depletion of the progenitor cell pool. We show that Sox9 maintains pancreatic progenitors by stimulating their proliferation, survival, and persistence in an undifferentiated state. Our finding that SOX9 regulates the Notch-effector HES1 suggests a Notch-dependent mechanism and establishes a possible genetic link between SOX factors and Notch. These findings will be of major significance for the development of in vitro protocols for cell replacement therapies.
Seymour
Philip A
PA
Department of Developmental and Cell Biology, University of California, Irvine, CA 92697-2300, USA.
Freude
Kristine K
KK
Tran
Man N
MN
Mayes
Erin E
EE
Jensen
Jan
J
Kist
Ralf
R
Scherer
Gerd
G
Sander
Maike
M
D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D049109:Cell Proliferation; D002470:Cell Survival / Q000235:genetics / Q000502:physiology; D005260:Female; D006609:High Mobility Group Proteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D010179:Pancreas / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*; D039904:Pluripotent Stem Cells / Q000378:metabolism / Q000502:physiology*; D055758:SOX9 Transcription Factor; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D014157:Transcription Factors / Q000172:deficiency / Q000235:genetics / Q000502:physiology*
D006609:High Mobility Group Proteins; D055758:SOX9 Transcription Factor; C527933:Sox9 protein, mouse; D014157:Transcription Factors