RESUMEN
Poly (ADP-ribose) polymerase 1 (PARP1)-dependent cell death in the retinal pigment epithelium (RPE) is implicated in dry age-related macular degeneration (AMD). Although PARP1 inhibitors are available for treating dry AMD, their delivery route is not ideal for patients. The aim of this study was to test the efficacy of a novel PARP1-inhibitory compound (PIC) in vitro and in vivo. This study presents PIC, a novel small molecule, with superior efficacy to PARP1 inhibitors in the market. PIC demonstrated a distinctive inhibitory profile against PARP isotypes than the FDA-approved PARP1 inhibitors. PIC inhibited PARP1 activation at an IC50 of 0.41 ± 0.15 nM in an enzyme-based assay in vitro and at IC50 and EC50 in ARPE-19 cells of 0.11 ± 0.02 nM and 0.22 ± 0.02 nM, respectively, upon H2O2 insult. PIC also moderated mitochondrial fission and depolarization and maintained cellular energy levels under oxidative stress in ARPE-19 cells. Furthermore, PIC demonstrated good corneal penetration in a rat model, presenting PIC as a promising candidate for eye drop therapeutics for dry AMD. When PIC was administered as an eye drop formulation, RPE morphology was preserved, maintaining the thickness of the outer nuclear layers under sodium iodate (SI) treatment in rats. In SI-treated rabbits, eye drop administration of PIC also retained the structural and functional integrity when analyzed using funduscopy and electroretinogram. Collectively, our data portray PIC as an attractive treatment measure for dry AMD.
Asunto(s)
Degeneración Macular/tratamiento farmacológico , Poli(ADP-Ribosa) Polimerasa-1/antagonistas & inhibidores , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Epitelio Pigmentado de la Retina/efectos de los fármacos , Administración Oftálmica , Animales , Antioxidantes/farmacología , Línea Celular , Modelos Animales de Enfermedad , Humanos , Yodatos , Degeneración Macular/inducido químicamente , Degeneración Macular/enzimología , Degeneración Macular/patología , Masculino , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Mitocondrias/patología , Absorción Ocular , Soluciones Oftálmicas , Estrés Oxidativo/efectos de los fármacos , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , Inhibidores de Poli(ADP-Ribosa) Polimerasas/administración & dosificación , Conejos , Ratas Sprague-Dawley , Epitelio Pigmentado de la Retina/enzimología , Epitelio Pigmentado de la Retina/patologíaRESUMEN
Platelet activation is an important process in the pathogenesis of atherothrombosis. However, the serial changes of platelet activation in atherosclerotic ischemic stroke have not been determined. In this study, we measured serially platelet expression of CD63 and P-selectin and platelet aggregability to ADP and collagen. Measurements were made 24 and 72 h and 7 and 90 days after the ischemic event in 29 patients with atherosclerotic ischemic stroke. Platelet aggregability was significantly decreased after 72 h compared to that at 24 h of stroke onset. However, platelet CD63 and P-selectin expression remained high even 90 days after the events. These findings suggest that platelet hyperactivation in atherosclerotic ischemic stroke may be sustained for a considerable period.