ABSTRACT
OBJECTIVE@#To To investigate the changes of MicroRNA-134, CREB and p-CREB expression in epileptic rat brains in order to elucidate the molecular mechanisms of epilepsy, providing new ideas for clinical treatment.@*METHODS@#Sixty-four Spraque-Dawley (SD) rats were divided into groups randomly, including control group, six hours after seizure group, 24-hour group, three-day group, one-week group, two-week group, four-week group, and eight-week group. All groups were placed under a pilocarpine-induced epilepsy model except the control group, and all rats were decapitated in different points of time. Brain specimens were taken for quantitative PCR experiments, immunohistochemistry and Western blot experiments. The results of the epilepsy model groups and the control group were compared.@*RESULTS@#There were no significant differences between the six hours after seizure group, the 24-hour group and the control group about the MicroRNA-134 levels. MicroRNA-134 in the hippocampus tissue of the three-day group significantly reduced compared with the control group; same result was observed with the one-week, two-week, four-week and eight-week groups. The CREB and p-CREB levels in the three-day group's rat hippocampus significantly increased compared with the control group; and the high levels of CREB and p-CREB were constantly maintained in the one-week, two-week, four-week and eight-week groups.@*CONCLUSIONS@#The MicroRNA-134 level of the epileptic rat hippocampus is significantly lower than normal after three days, and continues to maintain a low level; while CREB and p-CREB levels are rsignificantly increased after three days, and continue to remain at a high level. MicroRNA-134 plays a role in inhibiting synaptic plasticity by inhibiting CREB and p-CREB expressions.
ABSTRACT
Objective: To To investigate the changes of MicroRNA-134, CREB and p-CREB expression in epileptic rat brains in order to elucidate the molecular mechanisms of epilepsy, providing new ideas for clinical treatment. Methods: Sixty-four Spraque-Dawley (SD) rats were divided into groups randomly, including control group, six hours after seizure group, 24-hour group, three-day group, one-week group, two-week group, four-week group, and eight-week group. All groups were placed under a pilocarpine-induced epilepsy model except the control group, and all rats were decapitated in different points of time. Brain specimens were taken for quantitative PCR experiments, immunohistochemistry and Western blot experiments. The results of the epilepsy model groups and the control group were compared. Results: There were no significant differences between the six hours after seizure group, the 24-hour group and the control group about the MicroRNA-134 levels. MicroRNA-134 in the hippocampus tissue of the three-day group significantly reduced compared with the control group; same result was observed with the one-week, two-week, four-week and eight-week groups. The CREB and p-CREB levels in the three-day group's rat hippocampus significantly increased compared with the control group; and the high levels of CREB and p-CREB were constantly maintained in the one-week, two-week, four-week and eight-week groups. Conclusions: The MicroRNA-134 level of the epileptic rat hippocampus is significantly lower than normal after three days, and continues to maintain a low level; while CREB and p-CREB levels are rsignificantly increased after three days, and continue to remain at a high level. MicroRNA-134 plays a role in inhibiting synaptic plasticity by inhibiting CREB and p-CREB expressions.
ABSTRACT
<p><b>BACKGROUND</b>Annexin A7 (synexin, ANXA7) is a member of annexins, which plays an essential role in the regulation of calcium homeostasis. Considerable evidence shows that the pathogenetic mechanism of acquired epilepsy (AE) has been related to the imbalance of calcium homeostasis. The aim of this study was to investigate ANXA7 expression and cellular localization in the cortex and hippocampus in the rat lithium-pilocarpine model of AE.</p><p><b>METHODS</b>Totally 81 adult healthy male Wistar rats were randomly divided into control group (n = 9) and experimental group (n = 72), the experimental group contained eight subgroups according to sacrifice time (n = 9) (6-hour, 24-hour, 48-hour, 72-hour, 7-day, 15-day, 1-month, and 2-month). In the experimental group, rats were intraperitoneally injected by lithium-pilocarpine to induce AE model. We examined the expression and localization of ANXA7 via immunohistochemistry, double-label immunofluorescence with the use of neuron specific enolase (NSE) antibody, glial fibrillary acidic protein (GFAP) antibody and propidium iodide (PI), respectively. The data of optical density value were analyzed by analysis of variance.</p><p><b>RESULTS</b>ANXA7 expression increased significantly in the experimental groups especially in the acute period (6 hours, 24 hours, and 48 hours after the onset of seizure) using immunohistochemistry. Double-label immunofluorescence and confocal microscopy disclosed that ANXA7 localized in the neurons but not in astrocytes and did not localize in the nucleus, which were performed with anti-NSE, anti-GFAP and PI respectively.</p><p><b>CONCLUSION</b>ANXA7 may play a potential role in the pathogenetic mechanisms of the rat lithium-pilocarpine model of AE.</p>