Functional characterization of polymorphisms in the human TFPI gene.
Tissue factor pathway inhibitor (TFPI) is the primary physiological inhibitor of tissue factor (TF) induced coagulation. Low plasma TFPI levels have been shown to be associated with increased risk of arterial and venous thrombosis. Several clinical studies have reported that single nucleotide polymorphisms (SNPs) in the regulatory regions of the gene, such as the -287T/C, the -399C/T, and the -33T/C SNPs, may affect plasma TFPI levels. However, molecular studies investigating the functionality of the polymorphisms are lacking. In this study, we found that the -287C and -399T alleles affected the activity of the promoter using a reporter gene system. This was also the case for the -33T/C polymorphism. An association regarding the transcriptional activity of the reporter gene was detected between the -287C allele and the -33T/C polymorphism. Analysis of the polymorphic sites with electrophoretic mobility shift assay (EMSA) showed that all three polymorphisms potentially alter DNA-protein interactions. Based on these findings, we speculate that the -287C and the -33C alleles can be associated with lowered risk of thrombosis.
Department of Hematology, Oslo University Hospital, Kirkeveien 166, Oslo, Norway. grethe.skretting@medisin.uio.no
Grethe
G
Skretting
Benedicte
B
Stavik
Nina E
NE
Landvik
Christiane F
CF
Myklebust
Nina
N
Iversen
Shan
S
Zienolddiny
Per Morten
PM
Sandset
D020121:5' Untranslated Regions / Q000235:genetics; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D024202:Electrophoretic Mobility Shift Assay; D017930:Genes, Reporter; D006801:Humans; D008074:Lipoproteins / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D013927:Thrombosis / Q000235:genetics*; D014158:Transcription, Genetic
D020121:5' Untranslated Regions; D008074:Lipoproteins; C051928:lipoprotein-associated coagulation inhibitor