RESUMEN
The discovery of isozyme-selective histone deacetylase (HDAC) inhibitors is critical for understanding the biological functions of individual HDACs and for validating HDACs as drug targets. The isozyme HDAC10 contributes to chemotherapy resistance and has recently been described to be a polyamine deacetylase, but no studies toward selective HDAC10 inhibitors have been published. Using two complementary assays, we found Tubastatin A, an HDAC6 inhibitor, to potently bind HDAC10. We synthesized Tubastatin A derivatives and found that a basic amine in the cap group was required for strong HDAC10 binding. HDAC10 inhibitors mimicked knockdown by causing dose-dependent accumulation of acidic vesicles in a neuroblastoma cell line. Furthermore, docking into human HDAC10 homology models indicated that a hydrogen bond between a cap group nitrogen and the gatekeeper residue Glu272 was responsible for potent HDAC10 binding. Taken together, our data provide an optimal platform for the development of HDAC10-selective inhibitors, as exemplified with the Tubastatin A scaffold.
Asunto(s)
Benzamidas/metabolismo , Ácido Glutámico/química , Inhibidores de Histona Desacetilasas/metabolismo , Histona Desacetilasas/metabolismo , Ácidos Hidroxámicos/metabolismo , Animales , Benzamidas/síntesis química , Benzamidas/química , Transferencia Resonante de Energía de Fluorescencia , Células HeLa , Histona Desacetilasa 6/química , Histona Desacetilasa 6/metabolismo , Inhibidores de Histona Desacetilasas/síntesis química , Inhibidores de Histona Desacetilasas/química , Histona Desacetilasas/química , Humanos , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Ácidos Hidroxámicos/síntesis química , Ácidos Hidroxámicos/química , Ligandos , Simulación del Acoplamiento Molecular , Estructura Molecular , Unión Proteica , Relación Estructura-Actividad , Pez CebraRESUMEN
A virtual screening campaign is presented that led to small molecule inhibitors of thioredoxin reductase of Mycobacterium tuberculosis (MtTrxR) that target the protein-protein interaction site for the substrate thioredoxin (Trx). MtTrxR is a promising drug target because it dominates the Trx-dependent hydroperoxide metabolism and the reduction of ribonucleotides, thus facilitating survival and proliferation of M. tuberculosis. Moreover, MtTrxR sufficiently differs from its human homologs to suggest the possibility of selective inhibition if the MtTrxR-Trx interaction site is targeted. To this end, high-throughput docking of 6.5 million virtual compounds to the thioredoxin binding site of MtTrxR combined with constraints as filtering steps was applied. A total of 170 high-scoring compounds yielded 18 compounds that inhibited MtTrxR with IC50 values up to the low micromolar range, thus revealing that the protein-protein interaction site of MtTrxR is indeed druggable. Most importantly, selectivity toward MtTrxR in comparison to human TrxR (HsTrxR) is also demonstrated.
Asunto(s)
Inhibidores Enzimáticos/metabolismo , Inhibidores Enzimáticos/farmacología , Ensayos Analíticos de Alto Rendimiento , Simulación del Acoplamiento Molecular , Mycobacterium tuberculosis/enzimología , Reductasa de Tiorredoxina-Disulfuro/antagonistas & inhibidores , Reductasa de Tiorredoxina-Disulfuro/metabolismo , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/química , Escherichia coli/enzimología , Humanos , Conformación Proteica , Bibliotecas de Moléculas Pequeñas/química , Bibliotecas de Moléculas Pequeñas/metabolismo , Bibliotecas de Moléculas Pequeñas/farmacología , Reductasa de Tiorredoxina-Disulfuro/químicaRESUMEN
BACKGROUND: Endoscopic antireflux techniques have emerged as alternative therapies for gastroesophageal reflux disease (GERD). Endoscopic plication receives continuing interest as an effective and safe procedure. This treatment option has not been the subject of comparison with well-established operative therapies to date. The present study aimed at comparatively evaluating the effectiveness of endoscopic plication and laparoscopic fundoplication in terms of quality of life and symptom control. METHODS: Between October 2006 and April 2010, 60 patients with documented GERD were randomly assigned to undergo either endoscopic plication or laparoscopic fundoplication. Quality-of-life scores and symptom grading were recorded before treatment and at 3- and 12-month follow-up. Outcomes were compared with the statistical significance set at a p value of 0.05. RESULTS: Twenty-nine patients from the endoscopic group and 27 patients from the operative group were available at follow-up. Quality-of-life scores showed a substantial and similar increase for both groups after treatment. Symptoms of heartburn (p < 0.02), regurgitation (p < 0.004), and asthma (p = 0.03) were significantly improved in the endoscopic group, whereas laparoscopic fundoplication was more effective in controlling symptoms of heartburn (p < 0.01) and regurgitation (p < 0.05) compared to the endoscopic procedure. CONCLUSIONS: Endoscopic plication and laparoscopic fundoplication resulted in significant symptom improvement with similar quality-of-life scores in a selected patient population with GERD, whereas operative treatment was more effective in the relief of heartburn and regurgitation at the expense of higher short-term dysphagia rates.