Association of injury pattern and entrapment location inside damaged buildings in the 2016 Taiwan earthquake.

BACKGROUND/PURPOSE: To explore the association of patient injury patterns and entrapped locations inside damaged buildings in the 2016 Taiwan earthquake. METHODS: A retrospective analysis was conducted using the Tainan incident registry system. Residents inside nine conjunctive, 16-story (49.3 m in height) reinforced concrete buildings were categorized as non-injured, injured, and dead. Residents were classified into different groups according to their entrapped locations in height and the severity of building damage. The field triage acuity and trauma severity among groups were compared. Statistical significance was set at the level of 0.05. RESULTS: There were 309 enrollees with 76 (24.6%) non-injured, 118 (38.2%) injured, and 115 (37.2%) dead. Residents either in the high floors (odds ratio [OR] = 2.9, 95% CI: 1.5-5.8, p = 0.003) or in the collapsed buildings (OR = 18.2, 95% CI: 7.6-43.6, p < 0.001) were more likely to be dead. Injured patients who were located in the high floors were more likely to have severe field triage acuities (adjusted OR = 14.7, 95% CI: 1.8-118.0, p = 0.012); intracranial hemorrhage (12.5%), intrathoracic injury (18.8%), or intra-abdominal damage (12.5%) (All p < 0.05); the need for emergency surgical intervention (31.3%, p = 0.035); and major trauma (18.8%, p = 0.001). Residents in the collapsed buildings were more likely to have a crush injury (80.0%, p < 0.001) or crush syndrome (80.0%, p < 0.001). CONCLUSION: People entrapped at different heights of floors or in differently damaged buildings could have a distinct pattern of injury. Our findings may facilitate strategic approaches of patients entrapped in damaged buildings and may contribute to future training for field searches and rescues after earthquakes.

Design and characterization of a potent and selective dual ATP- and substrate-competitive subnanomolar bidentate c-Jun N-terminal kinase (JNK) inhibitor.

c-Jun N-terminal kinases (JNKs) represent valuable targets in the development of new therapies. Present on the surface of JNK is a binding pocket for substrates and the scaffolding protein JIP1 in close proximity to the ATP binding pocket. We propose that bidentate compounds linking the binding energies of weakly interacting ATP and substrate mimetics could result in potent and selective JNK inhibitors. We describe here a bidentate molecule, 19, designed against JNK. 19 inhibits JNK kinase activity (IC(50) = 18 nM; K(i) = 1.5 nM) and JNK/substrate association in a displacement assay (IC(50) = 46 nM; K(i) = 2 nM). Our data demonstrate that 19 targets for the ATP and substrate-binding sites on JNK concurrently. Finally, compound 19 successfully inhibits JNK in a variety of cell-based experiments, as well as in vivo where it is shown to protect against Jo-2 induced liver damage and improve glucose tolerance in diabetic mice.

Targeting metalloproteins by fragment-based lead discovery.

It has been estimated that nearly one-third of functional proteins contain a metal ion. These constitute a wide variety of possible drug targets including metalloproteinases, dehydrogenases, oxidoreductases, hydrolases, deacetylases, or many others in which the metal ion is either of catalytic or of structural nature. Despite the predominant role of a metal ion in so many classes of drug targets, current high-throughput screening techniques do not usually produce viable hits against these proteins, likely due to the lack of proper metal-binding pharmacophores in the current screening libraries. Herein, we describe a novel fragment-based drug discovery approach using a metal-targeting fragment library that is based on a variety of distinct classes of metal-binding groups designed to reliably anchor the fragments at the target's metal ions. We show that the approach can effectively identify novel, potent and selective agents that can be readily developed into metalloprotein-targeted therapeutics.

A novel pharmacophore model for the design of anthrax lethal factor inhibitors.

This study aims at the identification of novel structural features on the surface of the Zn-dependent metalloprotease lethal factor (LF) from anthrax onto which to design novel and selective inhibitors. We report that by targeting an unexplored region of LF that exhibits ligand-induced conformational changes, we could obtain inhibitors with at least 30-fold LF selectivity compared to two other most related human metalloproteases, MMP-2 and MMP-9. Based on these results, we propose a novel pharmacophore model that, together with the preliminarily identified compounds, should help the design of more potent and selective inhibitors against anthrax.

Synthesis and optimization of thiadiazole derivatives as a novel class of substrate competitive c-Jun N-terminal kinase inhibitors.

A series of thiadiazole derivatives has been designed as potential allosteric, substrate competitive inhibitors of the protein kinase JNK. We report on the synthesis, characterization and evaluation of a series of compounds that resulted in the identification of potent and selective JNK inhibitors targeting its JIP-1 docking site.

Structure-activity relationship studies of a novel series of anthrax lethal factor inhibitors.

We report on the identification of a novel small molecule inhibitor of anthrax lethal factor using a high-throughput screening approach. Guided by molecular docking studies, we carried out structure-activity relationship (SAR) studies and evaluated activity and selectivity of most promising compounds in in vitro enzyme inhibition assays and cellular assays. Selected compounds were further analyzed for their in vitro ADME properties, which allowed us to select two compounds for further preliminary in vivo efficacy studies. The data provided represents the basis for further pharmacology and medicinal chemistry optimizations that could result in novel anti-anthrax therapies.

Discovery of 2-(5-nitrothiazol-2-ylthio)benzo[d]thiazoles as novel c-Jun N-terminal kinase inhibitors.

A new series of 2-thioether-benzothiazoles has been synthesized and evaluated for JNK inhibition. The SAR studies led to the discovery of potent, allosteric JNK inhibitors with selectivity against p38.

Design, synthesis, and structure-activity relationship of substrate competitive, selective, and in vivo active triazole and thiadiazole inhibitors of the c-Jun N-terminal kinase.

We report comprehensive structure-activity relationship studies on a novel series of c-Jun N-terminal kinase (JNK) inhibitors. The compounds are substrate competitive inhibitors that bind to the docking site of the kinase. The reported medicinal chemistry and structure-based optimizations studies resulted in the discovery of selective and potent thiadiazole JNK inhibitors that display promising in vivo activity in mouse models of insulin insensitivity.

Identification of a new JNK inhibitor targeting the JNK-JIP interaction site.

JNK is a stress-activated protein kinase that modulates pathways implicated in a variety of disease states. JNK-interacting protein-1 (JIP1) is a scaffolding protein that enhances JNK signaling by creating a proximity effect between JNK and upstream kinases. A minimal peptide region derived from JIP1 is able to inhibit JNK activity both in vitro and in cell. We report here a series of small molecules JIP1 mimics that function as substrate competitive inhibitors of JNK. One such compound, BI-78D3, dose-dependently inhibits the phosphorylation of JNK substrates both in vitro and in cell. In animal studies, BI-78D3 not only blocks JNK dependent Con A-induced liver damage but also restores insulin sensitivity in mouse models of type 2 diabetes. Our findings open the way for the development of protein kinase inhibitors targeting substrate specific docking sites, rather than the highly conserved ATP binding sites. In view of its favorable inhibition profile, selectivity, and ability to function in the cellular milieu and in vivo, BI-78D3 represents not only a JNK inhibitor, but also a promising stepping stone toward the development of an innovative class of therapeutics.

Development of paramagnetic probes for molecular recognition studies in protein kinases.

We report on the synthesis and evaluation of an indazole-spin-labeled compound that was designed as an effective chemical probe for second site screening against the protein kinase JNK using NMR-based techniques. We demonstrate the utility of the derived compound in detecting and characterizing binding events at the protein kinase docking site. In addition, we report on the NMR-based design and synthesis of a bidentate compound spanning both the ATP site and the docking site. We show that the resulting compound has nanomolar affinity for JNK despite the relatively weak affinities of the individual fragments that constitute it. The approach demonstrates that targeting the docking site of protein kinases represents a valuable yet unexplored avenue to obtain potent kinase inhibitors with increased selectivity.

Rhodanine derivatives as selective protease inhibitors against bacterial toxins.

In this study, we analyzed a series of rhodanine derivatives, as potential inhibitors of bacterial toxins, namely the proteases anthrax lethal factor and the botulinum neurotoxin type A. Conducting an extensive structure-activity relationship study on rhodanine derivatives, we profiled their selectivity against the two bacterial toxins and two related human metalloproteases using in vitro assays. In addition, we examined initial in vitro ADME-Tox properties of selected compounds and their ability to protect lethal factor-induced cell death of macrophages. These data allowed the selection of one additional drug candidate for which preliminary in vivo efficacy studies against anthrax spores were conducted. Integration of these results with our structure-activity relationship studies provides a framework for the development of potential drug candidates against anthrax and botulinum.

A high-throughput screening approach to anthrax lethal factor inhibition.

A high-throughput screening approach was used to identify new inhibitors of the metallo-protease lethal factor from Bacillus anthracis. A library of approximately 14,000 compounds was screened using a fluorescence-based in vitro assay and hits were further characterized enzymatically via measurements of IC50 and Ki values against a small panel of metallo-proteases. This study led to the identification of new scaffolds that inhibit LF and the Botulinum Neurotoxin Type A in the low micromolar range, while sparing the human metallo-proteases MMP-2 and MMP-9. Therefore, these scaffolds could be further exploited for the development of potent and selective anti-toxin agents.