RESUMEN
The ongoing pandemic caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), necessitates strategies to identify prophylactic and therapeutic drug candidates for rapid clinical deployment. Here, we describe a screening pipeline for the discovery of efficacious SARS-CoV-2 inhibitors. We screen a best-in-class drug repurposing library, ReFRAME, against two high-throughput, high-content imaging infection assays: one using HeLa cells expressing SARS-CoV-2 receptor ACE2 and the other using lung epithelial Calu-3 cells. From nearly 12,000 compounds, we identify 49 (in HeLa-ACE2) and 41 (in Calu-3) compounds capable of selectively inhibiting SARS-CoV-2 replication. Notably, most screen hits are cell-line specific, likely due to different virus entry mechanisms or host cell-specific sensitivities to modulators. Among these promising hits, the antivirals nelfinavir and the parent of prodrug MK-4482 possess desirable in vitro activity, pharmacokinetic and human safety profiles, and both reduce SARS-CoV-2 replication in an orthogonal human differentiated primary cell model. Furthermore, MK-4482 effectively blocks SARS-CoV-2 infection in a hamster model. Overall, we identify direct-acting antivirals as the most promising compounds for drug repurposing, additional compounds that may have value in combination therapies, and tool compounds for identification of viral host cell targets.
Asunto(s)
Antivirales/farmacología , Tratamiento Farmacológico de COVID-19 , Reposicionamiento de Medicamentos/métodos , Pandemias , SARS-CoV-2 , Animales , COVID-19/prevención & control , COVID-19/virología , Línea Celular , Citidina/administración & dosificación , Citidina/análogos & derivados , Citidina/farmacología , Bases de Datos Farmacéuticas , Descubrimiento de Drogas/métodos , Evaluación Preclínica de Medicamentos/métodos , Células HeLa , Ensayos Analíticos de Alto Rendimiento/métodos , Humanos , Hidroxilaminas/administración & dosificación , Hidroxilaminas/farmacología , Mesocricetus , Nelfinavir/farmacología , SARS-CoV-2/efectos de los fármacos , SARS-CoV-2/fisiología , Replicación Viral/efectos de los fármacosRESUMEN
Clinical efficacy of two pretreatment regimens, sodium nitrite (SN) + hydroxylamine (HA) and SN + 4-dimethylaminophenol (DMAP) were evaluated in rats by studying various biochemical variables at different time intervals. Animals given single subcutaneous (s.c.) co-administration of SN+HA or SN+DMAP showed significantly elevated levels of blood bilirubin indicating hemolytic anemia. Increased levels of blood creatine phosphokinase (CPK), lactate dehydrogenase (LDH) and glutamic oxaloacetic transaminase (GOT) were indicative of aseptic necrosis at the injection site. On account of low methemoglobin reductase activity in human erythrocytes, a reduced sub-clinical dose of HA or DMAP is envisaged in humans.
Asunto(s)
Cianuros/antagonistas & inhibidores , Cianuros/toxicidad , Aminofenoles/administración & dosificación , Aminofenoles/toxicidad , Anemia Hemolítica/inducido químicamente , Animales , Antídotos/administración & dosificación , Antídotos/toxicidad , Evaluación Preclínica de Medicamentos , Hidroxilamina , Hidroxilaminas/administración & dosificación , Masculino , Metahemoglobinemia/inducido químicamente , Ratas , Ratas Endogámicas , Nitrito de Sodio/administración & dosificaciónRESUMEN
Intraventricular injections of 6-hydroxydopamine produced 95 percent depletion of telencephalic norepinephrine and 62 percent depletion of striatal dopamine in rats. Treated rats maintained body weight at subnormal levels and failed to increase food intake in response to a short-term decrease in glucose utilization. After treatment with the monoamine oxidase inhibitor pargyline, 6-hydroxydopamine produced no further norepinephrine depletion but increased the dopamnine depletion to 95 percent and produced complete aphagia. These effects are comparable to events that follow bilateral electrolytic lesions of the lateral hypothalanmus.