| BackgroundEpilepsy is a chronic neurological disease that affects larger populations and its incidence increases year by year. Temporal lobe epilepsy(TLE) is the most common type of refractory epilepsy because of its complex pathogenesis, and the exact etiology has not been elucidated. Currently, the treatments of TLE are still limited, only surgery can cure epilepsy, however, the Antiepileptic drugs(ADE) play an important role in controling epileptic seizures. As one of representative new antiepileptic drugs, Levetiracetam(LEV) is more secure than traditional drugs. Meta-analysis of randomized controlled trials(RCT) showed that Levetiracetam may be a first-line drug for all types of epilepsy(including status epilepticus(SE)) because of its higher security for adults, children, infants and even pregnant women. Finding effective biomarkers for diagnosing, observing progression, assessing pesticide effect and avoiding the side effects of drug is one emerging field of medical interest. C-fos(immediate early genes, IEGs) is a member of proto-oncogenes which can respond to external stimuli by the second messengers. C-fos is one indirect marker of active neurons of central nervous system(CNS). The expression of c-fos plays an extremely important role in evaluating nerve cell damage, Ischemia-reperfusion and so on. Calciumion(Ca2+) and calcium binding protein are important factors to maintain normal brain physiological function, calcium binding protein involved in cellular function procession through the regulation of numerous Ca2 +- dependent enzymes. Calcium binding protein has a protective effect on nerve cells; therefore, it may be used as a biomark to reflect tissue lesion and extent in brain.ObjestsTo estiblesh temporal lobe epilepsy rat model(lithium chloride – pilocarpine) with Sprague Dawley rats and investigate the effect of antiepileptic drug levetiracetam(LEV) on the expression of immediate early gene c-fos and calcium-binding proteins-Calretinin, and to further clarify the pathogenesis and pathophysiology of temporal lobe epilepsy, hoping to guide clinical diagnosis and treatment of epilepsy.MethodsWe established the rapid period(epilepsy period<3d) and slow period(epilepsy period>3d) model of temporal lobe epilepsy, and then randomly divided those models into Control Group, EP Group and LEV Group; The experimental models are deemed as success through rats’ behavior, hematoxylin-eosin staining and Fluoro-jade B staining. Besides, the expression of c-fos and Calretinin in hippocampus tissue was detected through the experimental techniques of Real-time RCR, Western-blot, immunohistochemistry and immunofluorescence; the data were analyzed by SPSS 21.0.Results15 rats were randomly chosen from 156 adult Sprague Dawley ones to acted as blank group, and the remaining 141 were used to establish epileptic models. The number of successful models was 122, and the success rate is 86.5%. The injured hippocampus cells were showed by H-E staining, and there are a large number of cells gathered which were showed by Fluoro-Jade B staining in EP group, and degree of brain injury is related to time. According to our data, the expression of c-fos was up-regulated at rapid period(especially at the time of 4h and 6h), while there was no significant difference in chronic period(at the time of 7d, 14 d and 28d). Compared with EP Group, LEV Group is also improved in rapid period(especially at the time of 4h and 6h), however, its c-fos expression is declined(P<0.05). The expression of calretinin in Control Group is higher, while EP Group declined rapidly in slow period(especially at the time of 7d, 14 d, 28d), however, the reduction is not obvious in rapid period. The expression level of c-fos in LEV Group is reduced, however, compared with EP Group, its levels of expression is increased, which has significant difference(P<0.05). Immunofluorescence double-labeling experiments showed that there is no co-localization relationship between c-fos and calretinin.Conclusions1. The temporal lobe epilepsy rat models were successfully established.2. The c-fos expression of hippocampus tissue of Temporal lobe epilepsy mice was higher in rapid period of epilepsy(especially at the time of 4h and 6h), while calretinin is rapidly reduced in slow period(especially at time of 14 d and 28d). Levetiracetam can reduce the expression of c-fos in rapid period(especially at the time of 4h and 6h) to a certain extent; however, the c-fos expression in EP group is still increasing when compared with the Control Group. Levetiracetam can increase the expression of calretinin in slow periods; however, calretinin is also still increasing when compared with the Control Group.3. Levetiracetam can reduce rats’ brain damage. 4. C-fos and calretinin have no co-localization relationships in the brains of model rats. |
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