HHEX promotes hepatic-lineage specification through the negative regulation of eomesodermin

• Published in: PloS one Vol. 9; no. 3; p. e90791
• Main Authors: Watanabe, Hitoshi, Takayama, Kazuo, Inamura, Mitsuru, Tachibana, Masashi, Mimura, Natsumi, Katayama, Kazufumi, Tashiro, Katsuhisa, Nagamoto, Yasuhito, Sakurai, Fuminori, Kawabata, Kenji, Furue, Miho Kusuda, Mizuguchi, Hiroyuki
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 20.03.2014; Public Library of Science (PLoS)
• Subjects: Animals; Biochemistry; Biology and Life Sciences; Biomarkers - metabolism; Biomedical materials; Body Patterning - drug effects; Body Patterning - genetics; Bone Morphogenetic Protein 4 - pharmacology; Cell Differentiation - drug effects; Cell Differentiation - genetics; Cell Lineage - drug effects; Cell Lineage - genetics; Developmental biology; Embryo cells; Embryogenesis; Embryonic growth stage; Embryonic stem cells; Embryonic Stem Cells - cytology; Embryonic Stem Cells - drug effects; Embryonic Stem Cells - metabolism; Endoderm; Endoderm - cytology; Endoderm - drug effects; Endoderm - metabolism; Gene expression; Gene Expression Regulation, Developmental - drug effects; Gene Knockdown Techniques; Genes; Growth factors; HeLa Cells; Homeobox; Homeodomain Proteins - genetics; Homeodomain Proteins - metabolism; Humans; Laboratories; Liver; Liver - cytology; Medical research; Metabolism; Mice; Molecular biology; Molecular modelling; Pharmaceutical sciences; Protein Binding - drug effects; Protein Binding - genetics; Proteins; Response Elements - genetics; RNA, Small Interfering - metabolism; Rodents; Specifications; Stem cells; T-Box Domain Proteins - genetics; T-Box Domain Proteins - metabolism; Transcription factors; Transcription Factors - genetics; Transcription Factors - metabolism; Transfection; Up-Regulation - drug effects; Up-Regulation - genetics; Japan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0090791

Human embryonic stem cells (hESCs) could provide a major window into human developmental biology, because the differentiation methods from hESCs mimic human embryogenesis. We previously reported that the overexpression of hematopoietically expressed homeobox (HHEX) in the hESC-derived definitive endoderm (DE) cells markedly promotes hepatic specification. However, it remains unclear how HHEX functions in this process. To reveal the molecular mechanisms of hepatic specification by HHEX, we tried to identify the genes directly targeted by HHEX. We found that HHEX knockdown considerably enhanced the expression level of eomesodermin (EOMES). In addition, HHEX bound to the HHEX response element located in the first intron of EOMES. Loss-of-function assays of EOMES showed that the gene expression levels of hepatoblast markers were significantly upregulated, suggesting that EOMES has a negative role in hepatic specification from the DE cells. Furthermore, EOMES exerts its effects downstream of HHEX in hepatic specification from the DE cells. In conclusion, the present results suggest that HHEX promotes hepatic specification by repressing EOMES expression.