PRDM6 is enriched in vascular precursors during development and inhibits endothelial cell proliferation, survival, and differentiation.
The mechanisms that regulate the differentiation program of multipotential stem cells remain poorly understood. In order to define the cues that delineate endothelial commitment from precursors, we screened for candidate regulatory genes in differentiating mouse embryoid bodies. We found that the PR/SET domain protein, PRDM6, is enriched in flk1(+) hematovascular precursor cells using a microarray-based approach. As determined by 5' RACE, full-length PRDM6 protein contains a PR domain and four Krüppel-like zinc fingers. In situ hybridization in mouse embryos demonstrates staining of the primitive streak, allantois, heart, outflow tract, paraaortic splanchnopleura (P-Sp)/aorto-gonadal-mesonephric (AGM) region and yolk sac, all sites known to be enriched in vascular precursor cells. PRDM6 is also detected in embryonic and adult-derived endothelial cell lines. PRDM6 is co-localized with histone H4 and methylates H4-K20 (but not H3) in vitro and in vivo, which is consistent with the known participation of PR domains in histone methyltransferase activity. Overexpression of PRDM6 in mouse embryonic endothelial cells induces apoptosis by activating caspase-3 and inducing G1 arrest. PRDM6 inhibits cell proliferation as determined by BrdU incorporation in endothelial cells, but not in rat aortic smooth muscle cells. Overexpression of PRDM6 also results in reduced tube formation in cultured endothelial cells grown in Matrigel. Taken together, our data indicate that PRDM6 is expressed by vascular precursors, has differential effects in endothelial cells and smooth muscle cells, and may play a role in vascular precursor differentiation and survival by modulating local chromatin-remodeling activity within hematovascular subpopulations during development.
Carolina Cardiovascular Biology Center, University of North Carolina, Chapel Hill, NC 27599-7126, USA.
Yaxu
Y
Wu
James E
JE
Ferguson
Hong
H
Wang
Rusty
R
Kelley
Rongqin
R
Ren
Holly
H
McDonough
James
J
Meeker
Peter C
PC
Charles
Hengbin
H
Wang
Cam
C
Patterson
D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D001808:Blood Vessels / Q000166:cytology* / Q000378:metabolism*; D002453:Cell Cycle; D002454:Cell Differentiation; D002460:Cell Line; D049109:Cell Proliferation; D002470:Cell Survival; D042783:Endothelial Cells / Q000166:cytology* / Q000201:enzymology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D008239:Lysine / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009928:Organ Specificity; D011496:Protein Methyltransferases; D051381:Rats; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
D006657:Histones; C509647:PRDM6, protein, mouse; D012097:Repressor Proteins; D000076983:Histone Methyltransferases; D011496:Protein Methyltransferases; D011495:Histone-Lysine N-Methyltransferase; D040301:Vascular Endothelial Growth Factor Receptor-2; D008239:Lysine