Inhibition of plasminogen activator inhibitor-1: its mechanism and effectiveness on coagulation and fibrosis.
OBJECTIVE
Serine protease inhibitors (serpin) play a central role in various pathological processes including coagulation, fibrinolysis, malignancy, and inflammation. Inhibition of serpins may prove therapeutic. As yet, however, only very few small molecule serpin inhibitors have been reported. For the first time, we apply a new approach of virtual screening to discover novel, orally active, small molecule serpin inhibitors and report their effectiveness.


RESULTS
We focused on a clinically important serpin, plasminogen activator inhibitor-1 (PAI-1), whose crystal structure has been described. We identify novel, orally active molecules able to enter into the strand 4 position (s4A) of the A beta-sheet of PAI-I as a mock compound. In vitro they specifically inhibit the PAI-1 activity and enhance fibrinolysis activity. In vivo the most effective molecule (TM5007) inhibits coagulation in 2 models: a rat arteriovenous (AV) shunt model and a mouse model of ferric chloride-induced testicular artery thrombosis. It also prevents the fibrotic process initiated by bleomycin in mouse lung.


CONCLUSIONS
The present study demonstrates beneficial in vitro and in vivo effects of novel PAI-1 inhibitors. Our methodology proves to be a useful tool to obtain effective inhibitors of serpin activity.
Izuhara
Yuko
Y
Institute of Medical Sciences, Tokai University, Kanagawa, Japan
Takahashi
Satoru
S
Nangaku
Masaomi
M
Takizawa
Shunya
S
Ishida
Hideyuki
H
Kurokawa
Kiyoshi
K
van Ypersele de Strihou
Charles
C
Hirayama
Noriaki
N
Miyata
Toshio
T
D000818:Animals; D000925:Anticoagulants / Q000737:chemistry / Q000494:pharmacology*; D001166:Arteriovenous Shunt, Surgical; D001665:Binding Sites; D001761:Bleomycin / Q000633:toxicity; D001777:Blood Coagulation / Q000187:drug effects; D002712:Chlorides; D003198:Computer Simulation; D004353:Drug Evaluation, Preclinical / Q000379:methods; D005290:Ferric Compounds / Q000633:toxicity; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008958:Models, Molecular; D017395:Plasminogen Activator Inhibitor 1 / Q000737:chemistry / Q000502:physiology*; D011487:Protein Conformation; D011658:Pulmonary Fibrosis / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control; D051381:Rats; D058258:Serpin E2; D015843:Serpins / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology; D013737:Testis / Q000098:blood supply; D013927:Thrombosis / Q000188:drug therapy; D014584:User-Computer Interface
D000925:Anticoagulants; D002712:Chlorides; D005290:Ferric Compounds; D017395:Plasminogen Activator Inhibitor 1; D058258:Serpin E2; C511869:Serpine2 protein, mouse; D015843:Serpins; D001761:Bleomycin; C024555:ferric chloride