RESUMEN
Hepatitis C virus (HCV) infection is treated with a combination of peginterferon alfa-2a/b and ribavirin. To address the limitations of this therapy, numerous small molecule agents are in development, which act by directly affecting key steps in the viral life-cycle. Herein we describe our discovery of quinolone derivatives, novel small-molecules that inhibit NS5b polymerase, a key enzyme of the viral life-cycle. A crystal structure of a quinoline analog bound to NS5B reveals that this class of compounds binds to allosteric site-II (non-nucleoside inhibitor-site 2, NNI-2) of this protein.
Asunto(s)
Antivirales/química , Inhibidores Enzimáticos/química , Hepacivirus/enzimología , Quinolonas/química , Proteínas no Estructurales Virales/antagonistas & inhibidores , Regulación Alostérica , Antivirales/síntesis química , Antivirales/farmacología , Sitios de Unión , Simulación por Computador , Cristalografía por Rayos X , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Quinolonas/síntesis química , Quinolonas/farmacología , Relación Estructura-Actividad , Proteínas no Estructurales Virales/metabolismoRESUMEN
Allografting and autografting of osteochondral tissues is a promising strategy to treat articular cartilage lesions in damaged joints. We developed a new model of fresh osteochondral allografting using the entire rabbit trochlea. The objective of the current study was to demonstrate that this model would achieve reproducible graft-host healing and maintain normal articular cartilage histologic, immunolocalization, and biochemical characteristics after transplantation under diverse storage and transplantation conditions. New Zealand white (n = 8) and Dutch belted (n = 8) rabbits underwent a 2-stage transplantation operation using osteochondral grafts that had been stored for 2 or 4 wk. Trochlear grafts harvested from the left knee were transplanted to the right knee as either autografts or allografts. Grafts were fixed with 22-gauge steel wire or 3-0 nylon suture. Rabbits were euthanized for evaluation at 1, 2, 4, 6, and 12 wk after transplantation. All grafts that remained in vivo for at least 4 wk demonstrated 100% interface healing by microCT. Trabecular bridging was present at the host-graft interface starting at 2 wk after transplantation, with no significant difference in cartilage histology between the various groups. The combined histology scores indicated minimal evidence of osteoarthritis. Immunostaining revealed that superficial zone protein was localized at the surface of all transplants. The rabbit trochlear model met our criteria for a successful model in regard to the ease of the procedure, low rate of surgical complications, relatively large articular cartilage surface area, and amount of host-graft bone interface available for analysis.