RNA Therapeutics to Control Fibrinolysis: Review on Applications in Biology and Medicine

Regulation of fibrinolysis, the process that degrades blood clots, is pivotal in maintaining haemostasis. Dysregulation leads to thrombosis or excessive bleeding. Proteins in the fibrinolysis system include fibrinogen, coagulation factor XIII, plasminogen, tissue plasminogen activator (tPA), urokinase (uPA), α2-antiplasmin, thrombin-activatable fibrinolysis inhibitor (TAFI), plasminogen activator inhibitor-1 (PAI-1), α2-macroglobulin, and others. While each of these is a potential therapeutic target for diseases, they each lack effective or long-acting inhibitors. Rapid advances in RNA-based technologies are creating powerful tools to control the expression of proteins. RNA agents can be long-acting and tailored to either decrease or increase production of a specific protein. Advances in nucleic acid delivery, such as by lipid nanoparticles, have enabled the delivery of RNA to the liver, where most proteins of coagulation and fibrinolysis are produced. This review will summarize the classes of RNA that induce 1) inhibition of protein synthesis, including small interfering RNA (siRNA) and antisense oligonucleotides (ASOs); 2) protein expression including messenger RNA (mRNA) and self-amplifying RNA (saRNA); and 3) gene editing for gene knockdown and precise editing. It will review specific examples of RNA therapies targeting proteins in the coagulation and fibrinolysis systems, and comment on the wide range of opportunities for controlling fibrinolysis for biological applications and future therapeutics using state-of-the-art RNA therapies.