Expressions of EF-Tumt and EF-Tsmt in epileptogenic zone of patients with refractory temporal lobe epilepsy

Objective: To examine the expressions of mitochondrial translation elongation factors Tu (EF-Tumt) and Ts (EF-Tsmt) in the epileptogenic zone of patients with refractory temporal lobe epilepsy. Methods: Epileptogenic zone resection specimens were obtained from 20 patients with refractory temporal lobe epilepsy. Control samples were temporal lobe cortex tissues derived from 6 non-epileptic patients with brain trauma. Histological examination was performed using hematoxylin and eosin (H&E) staining. EF-Tumt and EF-Tsmt expression patterns were evaluated using immunohistological analysis. Ultrastructural alterations were determined by transmission electron microscopy. Subcellular localization of target proteins was examined by immune electron microscopy. Results: Pathological changes and ultrastructural alterations were observed in all epileptogenic zone specimens taken from the patients with refractory temporal lobe epilepsy. Immunostaining indicated that the number of EF-Tumt-positive and EF-Tsmtpositive cells in epilepsy group was significantly higher than those in control subjects (50.99 ± 9.41 vs. 27.87 ± 3.46, P<0.05 and 53.00 ± 9.40 vs. 27.94 ± 7.05, P<0.05 respectively). Electron microscopy analysis further revealed that the number of EF-Tumt-positive and EF-Tsmt-positive particles in epilepsy patients was also higher than those in the controls (112.76 ± 20.79 vs. 32.67 ± 10.73, P<0.01; 111.48 ± 19.55 vs. 33.50 ± 8.62, P<0.01). In addition, both EF-Tumt and EF-Tsmt were predominantly localized within mitochondria. Conclusions: EF-Tumt and EFTsmt are up-regulated in the epileptogenic zone of patients with refractory temporal lobe epilepsy, implying that these proteins may contribute to the pathogenesis and progression of epilepsy.