Runx1 promotes angiogenesis by downregulation of insulin-like growth factor-binding protein-3.
Mouse embryos lacking the Runx1 transcription factor exhibit an angiogenic defect accompanied by the absence of hematopoietic stem cells (HSCs). To ask whether Runx1 plays a direct role in angiogenesis, we established a novel endothelial progenitor cell line, designated AEL-DeltaR1, from the aorta-gonad-mesonephros (AGM) region of Runx1-null mouse. We introduced Runx1 cDNA into AEL-DeltaR1 cells under the doxycycline-inducible promoter. The ability of AEL-DeltaR1 cells to form vascular networks on matrigel was highly enhanced by the restored expression of Runx1. By molecular comparison of mRNAs in AEL-DeltaR1 cells before and after the induction of Runx1, we found that mRNA expression of insulin-like growth factor-binding protein 3 (IGFBP-3) is downregulated by Runx1. Gel retardation and reporter assays revealed that Runx1 binds to the promoter region of mouse IGFBP-3 gene and represses its transcription. When IGFBP-3 was exogenously added in the matrigel assay, the angiogenesis-enhancing activity of Runx1 was suppressed in a dose-dependent manner. These results demonstrate that Runx1 is directly involved in angiogenesis by repression of IGFBP-3 mRNA expression.
Iwatsuki
Ken
K
Department of Tumor Biochemistry, The Tokyo Metropolitan Institute of Medical Science, Tokyo Metropolitan Organization for Medical Research, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8613, Japan.
Tanaka
Kiyoko
K
Kaneko
Tsuyoshi
T
Kazama
Ritsuko
R
Okamoto
Shiki
S
Nakayama
Yuki
Y
Ito
Yoshiaki
Y
Satake
Masanobu
M
Takahashi
Shin-Ichiro
S
Miyajima
Atsushi
A
Watanabe
Toshio
T
Hara
Takahiko
T
D000818:Animals; D002460:Cell Line; D049109:Cell Proliferation; D003094:Collagen / Q000737:chemistry; D050676:Core Binding Factor Alpha 2 Subunit; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015536:Down-Regulation / Q000235:genetics*; D004318:Doxycycline / Q000494:pharmacology; D004338:Drug Combinations; D024202:Electrophoretic Mobility Shift Assay; D004730:Endothelium, Vascular / Q000737:chemistry / Q000502:physiology*; D015870:Gene Expression / Q000235:genetics; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000235:genetics*; D007797:Laminin / Q000737:chemistry; D051379:Mice; D018345:Mice, Knockout; D018919:Neovascularization, Physiologic / Q000235:genetics* / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics; D011509:Proteoglycans / Q000737:chemistry; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D013234:Stem Cells / Q000737:chemistry / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
D050676:Core Binding Factor Alpha 2 Subunit; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D004338:Drug Combinations; D018972:Insulin-Like Growth Factor Binding Protein 3; D007797:Laminin; D011509:Proteoglycans; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; C493726:Runx1 protein, mouse; D014157:Transcription Factors; C059485:matrigel; D003094:Collagen; D004318:Doxycycline