Cellular Dynamics of Mouse Trophoblast Stem Cells: Identification of a Persistent Stem Cell Type.
Mouse trophoblast stem cells (TSCs) proliferate indefinitely in vitro, despite their highly heterogeneous nature. In this study, we sought to characterize TSC colony types by using methods based on cell biology and biochemistry for a better understanding of how TSCs are maintained over multiple passages. Colonies of TSCs could be classified into four major types: type 1 is compact and dome-shaped, type 4 is flattened but with a large multilayered cell cluster, and types 2 and 3 are their intermediates. A time-lapse analysis indicated that type 1 colonies predominantly appeared after passaging, and a single type 1 colony gave rise to all other types. These colony transitions were irreversible, but at least some type 1 colonies persisted throughout culture. The typical cells comprising type 1 colonies were small and highly motile, and they aggregated together to form primary colonies. A hierarchical clustering based on global gene expression profiles suggested that a TSC line containing more type 1 colony cells was similar to in vivo extraembryonic tissues. Among the known TSC genes examined, Elf5 showed a differential expression pattern according to colony type, indicating that this gene might be a reliable marker of undifferentiated TSCs. When aggregated with fertilized embryos, cells from types 1 and 2, but not from type 4, distributed to the polar trophectoderm in blastocysts. These findings indicate that cells typically found in type 1 colonies can persist indefinitely as stem cells and are responsible for the maintenance of TSC lines. They may provide key information for future improvements in the quality of TSC lines.
RIKEN BioResource Center, Tsukuba, Japan Graduate School of Life and Environmental Science, University of Tsukuba, Tsukuba, Japan.
Kaori
K
Motomura
RIKEN BioResource Center, Tsukuba, Japan.
Mami
M
Oikawa
RIKEN BioResource Center, Tsukuba, Japan.
Michiko
M
Hirose
RIKEN BioResource Center, Tsukuba, Japan Organization for Promotion of Tenure Track, University of Miyazaki, Miyazaki, Japan.
Arata
A
Honda
RIKEN BioResource Center, Tsukuba, Japan.
Sumie
S
Togayachi
Department of Physiology, Keio University School of Medicine, Tokyo, Japan.
Hiroyuki
H
Miyoshi
Faculty of Life and Environmental Sciences, University of Yamanashi, Yamanashi, Japan.
Yasuhide
Y
Ohinata
RIKEN BioResource Center, Tsukuba, Japan.
Michihiko
M
Sugimoto
RIKEN BioResource Center, Tsukuba, Japan Graduate School of Life and Environmental Science, University of Tsukuba, Tsukuba, Japan.
Kuniya
K
Abe
RIKEN BioResource Center, Tsukuba, Japan Graduate School of Life and Environmental Science, University of Tsukuba, Tsukuba, Japan.
Kimiko
K
Inoue
RIKEN BioResource Center, Tsukuba, Japan Graduate School of Life and Environmental Science, University of Tsukuba, Tsukuba, Japan The Center for Disease Biology and Integrative Medicine, Faculty of Medicine, University of Tokyo, Tokyo, Japan ogura@rtc.riken.go.jp.
Atsuo
A
Ogura
D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism; D005260:Female; D008297:Male; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014327:Trophoblasts / Q000166:cytology* / Q000378:metabolism
D004268:DNA-Binding Proteins; C500759:Elf5 protein, mouse; D014157:Transcription Factors
mouse; placenta; trophoblast stem cell