Structural requirements for the procoagulant activity of nucleic acids

• Published in: PloS one Vol. 7; no. 11; p. e50399
• Main Authors: Gansler, Julia, Jaax, Miriam, Leiting, Silke, Appel, Bettina, Greinacher, Andreas, Fischer, Silvia, Preissner, Klaus T
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 30.11.2012; Public Library of Science (PLoS)
• Subjects: Activated protein C; Activation; Affinity; Aptamers; Aptamers, Nucleotide - chemistry; Binding; Biochemistry; Biology; Blood clots; Blood Coagulation; Blood Coagulation Tests; Blood plasma; Clotting; Coagulants - chemistry; Coagulation; Cofactors; Comparative analysis; Deoxyribonucleic acid; DNA; Edema; Enzymes; Forming; Humans; Immunology; Inflammation; Inverted Repeat Sequences; Kininogen, High-Molecular-Weight - chemistry; Kininogens; Lupus; Medicine; Molecular weight; Neutrophils; Nucleic Acid Conformation; Nucleic acids; Nucleoli; Nucleolin; Oligomers; Oligoribonucleotides - chemistry; Phenols; Phosphoproteins - chemistry; Physiology; Prekallikrein - chemistry; Protein Binding; Protein C; Protein C - chemistry; Proteins; Ribonucleic acid; RNA; RNA polymerase; RNA, Small Nuclear - chemistry; RNA, Small Nuclear - genetics; RNA-Binding Proteins - chemistry; Side effects; snoRNA; Structure-Activity Relationship; Thrombin; Thrombin - chemistry; Vascular endothelial growth factor; Vascular Endothelial Growth Factor A - chemistry; Germany
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0050399

Nucleic acids, especially extracellular RNA, are exposed following tissue- or vessel damage and have previously been shown to activate the intrinsic blood coagulation pathway in vitro and in vivo. Yet, no information on structural requirements for the procoagulant activity of nucleic acids is available. A comparison of linear and hairpin-forming RNA- and DNA-oligomers revealed that all tested oligomers forming a stable hairpin structure were protected from degradation in human plasma. In contrast to linear nucleic acids, hairpin forming compounds demonstrated highest procoagulant activities based on the analysis of clotting time in human plasma and in a prekallikrein activation assay. Moreover, the procoagulant activities of the DNA-oligomers correlated well with their binding affinity to high molecular weight kininogen, whereas the binding affinity of all tested oligomers to prekallikrein was low. Furthermore, four DNA-aptamers directed against thrombin, activated protein C, vascular endothelial growth factor and nucleolin as well as the naturally occurring small nucleolar RNA U6snRNA were identified as effective cofactors for prekallikrein auto-activation. Together, we conclude that hairpin-forming nucleic acids are most effective in promoting procoagulant activities, largely mediated by their specific binding to kininogen. Thus, in vivo application of therapeutic nucleic acids like aptamers might have undesired prothrombotic or proinflammatory side effects.