RESUMEN
BACKGROUND: Viruses can modulate intracellular signalling pathways to complete their infectious cycle. Among these, the PI3K/Akt pathway allows prolonged survival of infected cells that favours viral replication. GSK3ß, a protein kinase downstream of PI3K/Akt, gets inactivated upon activation of the PI3K/Akt pathway, and its association with viral infections has been recently established. In this study, the role of GSK3ß during Dengue virus-2 (DENV-2) infection was investigated. METHODS: GSK3ß participation in the DENV-2 replication process was evaluated with pharmacological and genetic inhibition during early [0-12 h post-infection (hpi)], late (12-24 hpi), and 24 hpi in Huh7 and Vero cells. We assessed the viral and cellular processes by calculating the viral titre in the supernatants, In-Cell Western, western blotting and fluorescence microscopy. RESULTS: Phosphorylation of GSK3ß-Ser9 was observed at the early stages of infection; neither did treatment with small molecule inhibitors nor pre-treatment prior to viral infection of GSK3ß reduce viral titres of the supernatant at these time points. However, a decrease in viral titres was observed in cells infected and treated with the inhibitors much later during viral infection. Consistently, the infected cells at this stage displayed plasma membrane damage. Nonetheless, these effects were not elicited with the use of genetic inhibitors of GSK3ß. CONCLUSIONS: The results suggest that GSK3ß participates at the late stages of the DENV replication cycle, where viral activation may promote apoptosis and release of viral particles.
Asunto(s)
Virus del Dengue/enzimología , Glucógeno Sintasa Quinasas/antagonistas & inhibidores , Glucógeno Sintasa Quinasas/fisiología , Replicación Viral/fisiología , Aedes/citología , Animales , Apoptosis/fisiología , Western Blotting , Línea Celular Tumoral , Microscopía Fluorescente , Fosforilación/fisiología , Transducción de SeñalRESUMEN
BACKGROUND Viruses can modulate intracellular signalling pathways to complete their infectious cycle. Among these, the PI3K/Akt pathway allows prolonged survival of infected cells that favours viral replication. GSK3β, a protein kinase downstream of PI3K/Akt, gets inactivated upon activation of the PI3K/Akt pathway, and its association with viral infections has been recently established. In this study, the role of GSK3β during Dengue virus-2 (DENV-2) infection was investigated. METHODS GSK3β participation in the DENV-2 replication process was evaluated with pharmacological and genetic inhibition during early [0-12 h post-infection (hpi)], late (12-24 hpi), and 24 hpi in Huh7 and Vero cells. We assessed the viral and cellular processes by calculating the viral titre in the supernatants, In-Cell Western, western blotting and fluorescence microscopy. RESULTS Phosphorylation of GSK3β-Ser9 was observed at the early stages of infection; neither did treatment with small molecule inhibitors nor pre-treatment prior to viral infection of GSK3β reduce viral titres of the supernatant at these time points. However, a decrease in viral titres was observed in cells infected and treated with the inhibitors much later during viral infection. Consistently, the infected cells at this stage displayed plasma membrane damage. Nonetheless, these effects were not elicited with the use of genetic inhibitors of GSK3β. CONCLUSIONS The results suggest that GSK3β participates at the late stages of the DENV replication cycle, where viral activation may promote apoptosis and release of viral particles.
Asunto(s)
Animales , Replicación Viral/fisiología , Virus del Dengue/enzimología , Glucógeno Sintasa Quinasas/antagonistas & inhibidores , Glucógeno Sintasa Quinasas/fisiología , Fosforilación/fisiología , Transducción de Señal , Western Blotting , Apoptosis/fisiología , Aedes/citología , Línea Celular Tumoral , Microscopía FluorescenteRESUMEN
Valproic acid (VA) is an antiepileptic that is also used for the treatment of bipolar disorders. The objective was to evaluate the neuroprotective effects of VA on a brain ischemia model. The groups of male Wistar rats were: SO (sham-operated), ischemic and ischemic treated with VA (25, 50 and 100â¯mg/kg, p.o.). After anesthesia with ketamine and xilazine, the animals were subjected to clamping of carotid arteries (30â¯min) and reperfusion. Except for the carotid clamping, the SO group was submitted to the same procedure. On the 7th day, the animals were behaviorally evaluated, euthanized and had their brain dissected for neurochemical and immunohistochemical assays. The data were analyzed by ANOVA and Tukey as the post hoc test. The results showed that VA reversed partly or completely the behavioral (locomotor activity and memory deficits), neurochemical (striatal DA and DOPAC levels, brain nitrite and lipid peroxidation) and immunohistochemical alterations (iNOS, COX-2, HDAC and GSK3) observed in the untreated ischemic group. VA neuroprotective effects are probably related to its anti-inflammatory and antioxidant properties, as well as to HDAC and GSK3 inhibitory effects. These findings stimulate translational studies focusing on VA as a neuroprotective drug to be potentially used in the clinic for several neurological conditions.