Repressors NFI and NFY participate in organ-specific regulation of von Willebrand factor promoter activity in transgenic mice.
OBJECTIVE
To determine the role of repressors in cell type and organ-specific activation of von Willebrand factor (VWF) promoter sequences -487 to 247 in vivo.


RESULTS
Activation patterns of wild-type and mutant VWF promoters (sequences -487 to 247) containing mutations in repressors nuclear factor-I (NFI)- and nuclear factor Y (NFY)-binding sites were analyzed in transgenic mice. Mutation of the NFI-binding site activated the promoter in heart and lung endothelial cells, whereas mutation of the NFY-binding site activated the promoter in kidney vasculature. Immunofluorescence analyses showed that NFIB was predominant in heart and lung endothelial cells, whereas NFIX was predominantly detected in kidney endothelial cell nuclei. By using chromatin immunoprecipitation, we demonstrated that the distal lung-specific enhancer (containing a YY1 site) of the VWF gene is brought in proximity to the NFI binding site.


CONCLUSIONS
The NFI and NFY repressors contribute differentially to organ-specific regulation of the VWF promoter, and the organ-specific action of NFI may reflect its organ-specific isoform distribution. In addition, the lung-specific enhancer region of the endogenous VWF gene may inhibit NFI repressor function through chromatin looping, which can approximate the 2 regions.
Nassiri
Marjan
M
Department of Medicine, University of Alberta, Edmonton, AL, Canada.
Liu
Ju
J
Kulak
Stephen
S
Uwiera
Richard R E
RR
Aird
William C
WC
Ballermann
Barbara J
BJ
Jahroudi
Nadia
N
D000818:Animals; D001665:Binding Sites; D002478:Cells, Cultured; D047369:Chromatin Immunoprecipitation; D003331:Coronary Vessels / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006801:Humans; D007668:Kidney / Q000098:blood supply; D007763:Lac Operon; D008168:Lung / Q000098:blood supply; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009154:Mutation; D051839:NFI Transcription Factors / Q000235:genetics / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D050986:YY1 Transcription Factor / Q000235:genetics / Q000378:metabolism; D014841:von Willebrand Factor / Q000235:genetics* / Q000378:metabolism
D051839:NFI Transcription Factors; C484683:Nfib protein, mouse; C497650:Nfix protein, mouse; D012333:RNA, Messenger; D050986:YY1 Transcription Factor; C494698:YY1 protein, human; C494699:Yy1 protein, mouse; D014841:von Willebrand Factor