In vitro, antithrombotic and bleeding time studies of BMS-654457, a small-molecule, reversible and direct inhibitor of factor XIa

SummaryThe in vitro anticoagulant activities of recombinant desulphatohirudin (r-hirudin) were studied in the activated partial thromboplastin time (APTT) and the thrombin generation test : systems. In the APTT at concentrations below 5 μg/ml, r-hirudin showed a dose-response curye. At concentrations above 5 μg/ml, the plasma became unclottable, but in the thrombin generation test , at least 10 μg/ml of r-hirudin was required for full inhibition of thrombin generation. The antithrombotic effect was assessed using a rabbit venous stasis model; 150 μg/ml r-hirudin completely prevented thrombus formation at 10 and 20 min stasis. At antithrombotic dose, the mean bleeding time ratio measured in a rabbit ear template model, was not prolonged over control values. At higher doses, the bleeding time ratios were higher than those observed for the same dosage of heparin. These data indicate that while r-hirudin is an effective antithrombotic agent, antithrombotic doses have to be carefully titrated to avoid excessive bleeding.

Download Full-text

The d-Enantiomer Form of Indobufen Totally Accounts for the Anti-Cyclooxygenase and Antiplatelet Activity Ex Vivo and for the Increase in Bleeding Time by Indobufen in Man

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648422 ◽

1992 ◽

Vol 67 (02) ◽

pp. 258-263 ◽

Cited By ~ 12

Author(s):

Raffaele De Caterina ◽

Rosa Sicari ◽

An Yan ◽

Walter Bernini ◽

Daniela Giannessi ◽

...

Keyword(s):

Arachidonic Acid ◽

Platelet Aggregation ◽

Plasma Levels ◽

Bleeding Time ◽

Ex Vivo ◽

Random Sequence ◽

Antiplatelet Agent ◽

Antiplatelet Drug ◽

Double Blind

SummaryIndobufen is an antiplatelet drug able to inhibit thromboxane production and cyclooxygenase-dependent platelet aggregation by a reversible inhibition of cyclooxygenase. Indobufen exists in two enantiomeric forms, of which only d-indobufen is active in vitro in inhibiting cyclooxygenase. In order to verify that also inhibition of platelet function is totally accounted for by d-indobufen, ten patients with proven coronary artery disease (8 male, 2 female, age, mean ± S.D., 58.7 ± 7.5 years) were given, in random sequence, both 100 mg d-indobufen and 200 mg dl-indobufen as single administrations in a double-blind crossover design study with a washout period between treatments of 72 h. In all patients thromboxane (TX) B2 generation after spontaneous clotting (at 0, 1, 2, 4, 6, 8, 12, 24 h), drug plasma levels (at the same times), platelet aggregation in response to ADP, adrenaline, arachidonic acid, collagen, PAF, and bleeding time (at 0, 2, 12 h) were evaluated after each treatment. Both treatments determined peak inhibition of TXB2 production at 2 h from administration, with no statistical difference between the two treatments (97 ±3% for both treatments). At 12 h inhibition was 87 ± 6% for d-indobufen and 88 ± 6% for dl-indobufen (p = NS). Inhibition of TXB2 production correlated significantly with plasma levels of the drugs. Maximum inhibitory effect on aggregation was seen in response to collagen 1.5 pg/ml (63 ± 44% for d-indobufen and 81 ± 22% for dl-indobufen) and arachidonic acid 0.5-2 mM (78 ± 34% for d-indobufen and 88 ± 24% for dl-indobufen) at 2 h after each administration. An effect of both treatments on platelet aggregation after 12 h was present only for adrenaline 2 μM (55 ± 41% for d-indobufen and 37 ± 54% for dl-indobufen), collagen 1.5 pg/ml (69 ± 30% for d-indobufen and 51 ± 61% for dl-indobufen), arachidonic acid 0.5-2 mM (56 ± 48% for d-indobufen and 35 ± 49% for dl-indobufen). The extent of inhibition of TX production and the extent of residual platelet aggregation were never significantly different between treatments. Bleeding time prolongation was similar in the two treatment groups without showing a pronounced and long lasting effect (from 7.0 ± 2.0 min to 10.0 ± 3.0 min at 2 h and 8.0 ± 2.0 min at 12 h for d-indobufen; from 6.0 ±1.0 min to 8.5 ± 2.0 min at 2 h and 8.0 ± 1.0 min at 12 h for dl-indobufen). These results demonstrate that the biological activity of dl-indobufen as an antiplatelet agent in vivo is totally accounted for by d-indobufen.

Download Full-text

The Effect of Dextran of Various Molecular Weight on the Coagulation in Dogs

Thrombosis and Haemostasis ◽

10.1055/s-0038-1654535 ◽

1961 ◽

Vol 06 (01) ◽

pp. 015-024 ◽

Cited By ~ 32

Author(s):

Sven Erik Bergentz ◽

Oddvar Eiken ◽

Inga Marie Nilsson

Keyword(s):

Molecular Weight ◽

Body Weight ◽

High Molecular Weight ◽

Bleeding Time ◽

Factor Vii ◽

Low Molecular Weight ◽

Factor V ◽

Coagulation Mechanism ◽

Coagulation Defects

Summary1. Infusions of low molecular weight dextran (Mw = 42 000) to dogs in doses of 1—1.5 g per kg body weight did not produce any significant changes in the coagulation mechanism.2. Infusions of high molecular weight dextran (Mw = 1 000 000) to dogs in doses of 1—1.5 g per kg body weight produced severe defects in the coagulation mechanism, namely prolongation of bleeding time and coagulation time, thrombocytopenia, pathological prothrombin consumption, decrease of fibrinogen, prothrombin and factor VII, factor V and AHG.3. Heparin treatment of the dogs was found to prevent the decrease of fibrinogen, prothrombin and factor VII, and factor V otherwise occurring after injection of high molecular weight dextran. Thrombocytopenia was not prevented.4. In in vitro experiments an interaction between fibrinogen and dextran of high and low molecular weight was found to take place in systems comprising pure fibrinogen. No such interaction occurred in the presence of plasma.5. It is concluded that the coagulation defects induced by infusions of high molecular weight dextran are due to intravascular coagulation.

Download Full-text

Faculty Opinions recommendation of Identification of new small molecule inhibitors of cystic fibrosis transmembrane conductance regulator protein: in vitro and in vivo studies.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1069767.522696 ◽

2007 ◽

Author(s):

Kim Barrett

Keyword(s):

Cystic Fibrosis ◽

Small Molecule ◽

Small Molecule Inhibitors ◽

In Vivo Studies ◽

Transmembrane Conductance Regulator ◽

Transmembrane Conductance ◽

Regulator Protein ◽

Cystic Fibrosis Transmembrane

Download Full-text

Cyclodextrin-Based Supramolecular Complexes of Osteoinductive Agents for Dental Tissue Regeneration

Pharmaceutics ◽

10.3390/pharmaceutics13020136 ◽

2021 ◽

Vol 13 (2) ◽

pp. 136

Author(s):

Masahiko Terauchi ◽

Atsushi Tamura ◽

Yoshinori Arisaka ◽

Hiroki Masuda ◽

Tetsuya Yoda ◽

...

Keyword(s):

Growth Factors ◽

Bone Formation ◽

Small Molecule ◽

Tissue Regeneration ◽

Alveolar Bone ◽

Inclusion Complexation ◽

Dental Tissue ◽

Polyelectrolyte Complexes ◽

Small Molecule Drugs

Oral tissue regeneration has received growing attention for improving the quality of life of patients. Regeneration of oral tissues such as alveolar bone and widely defected bone has been extensively investigated, including regenerative treatment of oral tissues using therapeutic cells and growth factors. Additionally, small-molecule drugs that promote bone formation have been identified and tested as new regenerative treatment. However, treatments need to progress to realize successful regeneration of oral functions. In this review, we describe recent progress in development of regenerative treatment of oral tissues. In particular, we focus on cyclodextrin (CD)-based pharmaceutics and polyelectrolyte complexation of growth factors to enhance their solubility, stability, and bioactivity. CDs can encapsulate hydrophobic small-molecule drugs into their cavities, resulting in inclusion complexes. The inclusion complexation of osteoinductive small-molecule drugs improves solubility of the drugs in aqueous solutions and increases in vitro osteogenic differentiation efficiency. Additionally, various anionic polymers such as heparin and its mimetic polymers have been developed to improve stability and bioactivity of growth factors. These polymers protect growth factors from deactivation and degradation by complex formation through electrostatic interaction, leading to potentiation of bone formation ability. These approaches using an inclusion complex and polyelectrolyte complexes have great potential in the regeneration of oral tissues.

Download Full-text

A small molecule HIF-1α stabilizer that accelerates diabetic wound healing

Nature Communications ◽

10.1038/s41467-021-23448-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Guodong Li ◽

Chung-Nga Ko ◽

Dan Li ◽

Chao Yang ◽

Wanhe Wang ◽

...

Keyword(s):

Wound Healing ◽

Small Molecule ◽

Hypoxia Inducible Factor ◽

Diabetic Patients ◽

Diabetic Mice ◽

Impaired Wound Healing ◽

Von Hippel Lindau ◽

Design And Synthesis

AbstractImpaired wound healing and ulcer complications are a leading cause of death in diabetic patients. In this study, we report the design and synthesis of a cyclometalated iridium(III) metal complex 1a as a stabilizer of hypoxia-inducible factor-1α (HIF-1α). In vitro biophysical and cellular analyses demonstrate that this compound binds to Von Hippel-Lindau (VHL) and inhibits the VHL–HIF-1α interaction. Furthermore, the compound accumulates HIF-1α levels in cellulo and activates HIF-1α mediated gene expression, including VEGF, GLUT1, and EPO. In in vivo mouse models, the compound significantly accelerates wound closure in both normal and diabetic mice, with a greater effect being observed in the diabetic group. We also demonstrate that HIF-1α driven genes related to wound healing (i.e. HSP-90, VEGFR-1, SDF-1, SCF, and Tie-2) are increased in the wound tissue of 1a-treated diabetic mice (including, db/db, HFD/STZ and STZ models). Our study demonstrates a small molecule stabilizer of HIF-1α as a promising therapeutic agent for wound healing, and, more importantly, validates the feasibility of treating diabetic wounds by blocking the VHL and HIF-1α interaction.

Download Full-text

Transcriptional perturbation of protein arginine methyltransferase-5 exhibits MTAP-selective oncosuppression

Scientific Reports ◽

10.1038/s41598-021-86834-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sara Busacca ◽

Qi Zhang ◽

Annabel Sharkey ◽

Alan G. Dawson ◽

David A. Moore ◽

...

Keyword(s):

Small Molecule ◽

Selective Vulnerability ◽

Dependent Manner ◽

Histone H4 ◽

Wild Type ◽

Protein Arginine Methyltransferase ◽

Arginine Methyltransferase ◽

Methylthioadenosine Phosphorylase ◽

Protein Arginine Methyltransferase 5

AbstractWe hypothesized that small molecule transcriptional perturbation could be harnessed to target a cellular dependency involving protein arginine methyltransferase 5 (PRMT5) in the context of methylthioadenosine phosphorylase (MTAP) deletion, seen frequently in malignant pleural mesothelioma (MPM). Here we show, that MTAP deletion is negatively prognostic in MPM. In vitro, the off-patent antibiotic Quinacrine efficiently suppressed PRMT5 transcription, causing chromatin remodelling with reduced global histone H4 symmetrical demethylation. Quinacrine phenocopied PRMT5 RNA interference and small molecule PRMT5 inhibition, reducing clonogenicity in an MTAP-dependent manner. This activity required a functional PRMT5 methyltransferase as MTAP negative cells were rescued by exogenous wild type PRMT5, but not a PRMT5E444Q methyltransferase-dead mutant. We identified c-jun as an essential PRMT5 transcription factor and a probable target for Quinacrine. Our results therefore suggest that small molecule-based transcriptional perturbation of PRMT5 can leverage a mutation-selective vulnerability, that is therapeutically tractable, and has relevance to 9p21 deleted cancers including MPM.

Download Full-text

A small molecule compound with an indole moiety inhibits the main protease of SARS-CoV-2 and blocks virus replication

Nature Communications ◽

10.1038/s41467-021-20900-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Shin-ichiro Hattori ◽

Nobuyo Higashi-Kuwata ◽

Hironori Hayashi ◽

Srinivasa Rao Allu ◽

Jakka Raghavaiah ◽

...

Keyword(s):

Small Molecule ◽

Covalent Bond ◽

Amino Acid Residues ◽

X Ray ◽

Viral Breakthrough ◽

Main Protease ◽

Small Molecule Compound ◽

Polar Interactions ◽

High Concentrations

AbstractExcept remdesivir, no specific antivirals for SARS-CoV-2 infection are currently available. Here, we characterize two small-molecule-compounds, named GRL-1720 and 5h, containing an indoline and indole moiety, respectively, which target the SARS-CoV-2 main protease (Mpro). We use VeroE6 cell-based assays with RNA-qPCR, cytopathic assays, and immunocytochemistry and show both compounds to block the infectivity of SARS-CoV-2 with EC50 values of 15 ± 4 and 4.2 ± 0.7 μM for GRL-1720 and 5h, respectively. Remdesivir permitted viral breakthrough at high concentrations; however, compound 5h completely blocks SARS-CoV-2 infection in vitro without viral breakthrough or detectable cytotoxicity. Combination of 5h and remdesivir exhibits synergism against SARS-CoV-2. Additional X-ray structural analysis show that 5h forms a covalent bond with Mpro and makes polar interactions with multiple active site amino acid residues. The present data suggest that 5h might serve as a lead Mpro inhibitor for the development of therapeutics for SARS-CoV-2 infection.

Download Full-text