PB0422 - The piperazinyl-purine analogue MK177 is a bifunctional drug with promising anti-ischemic and anti-thrombotic potential

Sunday, June 25, 2023

18:30 – 19:30 ET

Room: Exhibition

Co-Author(s)

MK

Maria Koufaki

Research Director
Institute of Chemical Biology, National Hellenic Research Foundation, Athens, Greece
Athens, Attiki, Greece
ML

Madelene Lindkvist

PhD
School of Medical Sciences, Cardiovascular Research Centre Örebro University, Sweden
Örebro, Ostergotlands Lan, Sweden
TF

Theano Fotopoulou

Researcher
Institute of Chemical Biology, National Hellenic Research Foundation, Athens, Greece
Athens, Attiki, Greece
HN

Hayat Nuru

Medical student
School of Medical Sciences, Cardiovascular Research Centre Örebro University, Sweden
Örebro, Orebro Lan, Sweden
MZ

Maria Zervou

Senior Researcher
Institute of Chemical Biology, National Hellenic Research Foundation, Athens, Greece
Athens, Attiki, Greece
JJ

Josef Jakobsson

Medical student
School of Medical Sciences, Cardiovascular Research Centre Örebro University, Sweden
Örebro, Orebro Lan, Sweden
DP

Dimitra Pournara

Researcher
Institute of Chemical Biology, National Hellenic Research Foundation, Athens, Greece
Athens, Attiki, Greece
EI

Eleni Ifanti

Researcher
Institute of Chemical Biology, National Hellenic Research Foundation, Athens, Greece
Athens, Attiki, Greece
EK

Eftichia Kritsi

Researcher
Institute of Chemical Biology, National Hellenic Research Foundation, Athens, Greece
Athens, Attiki, Greece
KN

Kristofer Nilsson

Associate professor
School of Medical Sciences, Cardiovascular Research Centre Örebro University, Sweden
Örebro, Orebro Lan, Sweden
EL

Eva Lindström

Senior Lecturer
Department of Biomedical and Clinical Sciences, Linköping University, Sweden
Linköping, Ostergotlands Lan, Sweden
KF

Karin H. Fransén

Associate professor
School of Medical Sciences, Cardiovascular Research Centre Örebro University, Sweden
Orebro, Orebro Lan, Sweden

Presenting Author(s)

Sofia Ramström, PhD, Associate Professor (she/her/hers)

Associate professor
School of Medical Sciences, Cardiovascular Research Centre Örebro University, Sweden
Örebro, Orebro Lan, Sweden

Co-Author(s)

MG

Magnus Grenegård

Professor
School of Medical Sciences, Cardiovascular Research Centre Örebro University, Sweden
Örebro, Orebro Lan, Sweden

Background: Nitrate ester bearing 6-piperazinyl-purine analogues (denoted MK drugs) have been shown to be cardioprotective in animal infarction models and to inhibit Janus kinase (JAK) and Rho-associated kinase (ROCK). Despite the nitrate ester moiety, the MK drugs do not release nitric oxide (NO).

Aims: To further improve the therapeutic potential of MK compounds, we synthesized a derivative with two nitrate ester moieties and characterized this drug (MK177) in various experimental models.

Methods: We utilize organic chemistry platforms to synthesize and purify MK177, in silico analysis of binding interactions to molecular targets, cell-free and cellular assays to elucidate anti-thrombotic and anti-ischemic activities, tissue models to analyze vasodilation, and animal models to evaluate drug activities in vivo.

Results: MK177 inhibited collagen-induced platelet aggregation (72±12.6 % inhibition of maximal aggregation response, mean±SD, n=7) and also inhibited GPVI activation-induced fibrinogen binding and exposure of P-selectin and CD63 as measured by flow cytometry. Western blot analyses showed that MK177 reduced ROCK-dependent phosphorylation of MYPT-1 in platelets. Conversely, MK177 did not cause NO/cyclic GMP-dependent phosphorylation of vasodilator-stimulated phosphoprotein. In anesthetized pigs, infusion of MK177 reduced the arterial blood pressure. Analysis of exhaled air confirmed release of NO. MK177 caused dose-dependent relaxation of iliac arteries (87±6.8 % relaxation of phenylephrine-precontracted arteries, n=5) mediated by activation of the NO/cyclic GMP signaling pathway in vascular smooth muscle cells. It is noteworthy that other members of the MK family (which are mononitrate or non-nitrate ester derivatives) did not cause NO-induced vasodilation.

Conclusion(s): We have successfully developed a bifunctional molecule, MK177, that acts by NO-dependent and NO-independent mechanisms. MK 177, in common with nitroglycerin, induced cardiovascular NO effects in vivo and relaxed vessels in vitro. Opposite to nitroglycerin, MK177 also prevented platelet activation via NO-independent ROCK inhibition. The bifunctional nature of MK177 can be of significance in future management of thrombotic and ischemic disease.