ImmunoSensation - the immune sensory system

Nucleic Acid Ther . 2020 Jun 2.

Selective Modulation of the Protease Activated Protein C Using Exosite Inhibiting Aptamers

Vittorio Branchi, Tobias J Weismüller, Taotao Zhou, Jonas Henn, Alexander Semaan, Tim R Glowka, Maria Gonzalez-Carmona, Christian Strassburg, Jörg C Kalff, Steffen Manekeller, Hanno Matthaei, Hiroki Kato, Hideo Nagatomo, Mitsuo Nakai, Tatsuhiro Sakaiya, Hidenori Terasaki, Tadashi Kondo, Yoichiro Hironaka, Katsuya Shimizu, Keisuke Shigemori, Nasim Shahidi Hamedani, Jens Müller, Fabian Tolle, Heiko Rühl, Behnaz Pezeshkpoor, Kerstin Liphardt, Johannes Oldenburg, Günter Mayer, Bernd Pötzsch

Activated protein C (APC) is a serine protease with anticoagulant and cytoprotective activities. Nonanticoagulant APC mutants show beneficial effects as cytoprotective agents. To study, if such biased APC signaling can be achieved by APC-binding ligands, the aptamer technology has been used. A G-quadruplex-containing aptamer, G-NB3, has been selected that binds to the basic exosite of APC with a KD of 0.2 nM and shows no binding to APC-related serine proteases or the zymogen protein C. G-NB3 inhibits the inactivation of activated cofactors V and VIII with IC50 values of 11.6 and 13.1 nM, respectively, without inhibiting the cytoprotective and anti-inflammatory functions of APC as tested using a staurosporine-induced apoptosis assay and a vascular barrier protection assay. In addition, G-NB3 prolongs the plasma half-life of APC through inhibition of APC-serine protease inhibitor complex formation. These physicochemical and functional characteristics qualify G-NB3 as a promising therapeutic agent usable to enhance the cytoprotective functions of APC without increasing the risk of APC-related hemorrhage.

PMID: 32486960