Regulation of fibrinogen production by microRNAs.
Elevated levels of fibrinogen are associated with increased risk of cardiovascular disease, whereas low fibrinogen can lead to a bleeding disorder. We investigated whether microRNAs (miRNAs), known to act as post-transcriptional regulators of gene expression, regulate fibrinogen production. Using transfection of a library of 470 annotated human miRNA precursor molecules in HuH7 hepatoma cells and quantitative measurements of fibrinogen production, we identified 23 miRNAs with down-regulating (up to 64% decrease) and 4 with up-regulating effects (up to 129% increase) on fibrinogen production. Among the down-regulating miRNAs, we investigated the mechanism of action of 3 hsa-miR-29 family members and hsa-miR-409-3p. Overexpression of hsa-miR-29 members led to decreased steady-state levels of all fibrinogen gene (FGA, FGB, and FGG) transcripts in HuH7 cells. Luciferase reporter gene assays demonstrated that this was independent of miRNA-fibrinogen 3'-untranslated region interactions. In contrast, overexpression of hsa-miR-409-3p specifically lowered fibrinogen Bβ mRNA levels, and this effect was dependent on a target site in the fibrinogen Bβ mRNA 3'-untranslated region. This study adds to the known mechanisms that control fibrinogen production, points toward a potential cause of variable circulating fibrinogen levels, and demonstrates that a screening approach can identify miRNAs that regulate clinically important proteins.
Fort
Alexandre
A
Department of Genetic Medicine and Development, University of Geneva Faculty of Medicine, Geneva, Switzerland.
Borel
Christelle
C
Migliavacca
Eugenia
E
Antonarakis
Stylianos E
SE
Fish
Richard J
RJ
Neerman-Arbez
Marguerite
M
D020413:3' Untranslated Regions; D002460:Cell Line; D045744:Cell Line, Tumor; D005340:Fibrinogen / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*
D020413:3' Untranslated Regions; D035683:MicroRNAs; D005340:Fibrinogen