Transforming growth factor beta 1 reduces spontaneous recurrent seizures and inhibits activation of glial cells in rats

AIM: To investigate the mechanism that intranasal transforming growth factor beta 1 (TGF-β₁) reduces the occurrence of spontaneous seizures after status epilepticus (SE) induced by pilocarpine. METHODS: The rats received recombinant human TGF-β1 or the same volume of PBS, and were treated with pilocarpine to induce SE. All the rats were put into a special cage for video monitoring 7 days later. The determinations of glial fibrillary acidic protein (GFAP) and ionized calcium-binding adaptor molecule 1 (Iba1) positive cells by the method of immunohistochemistry were performed to evaluate the activation levels of the gliocytes in hippocampus. The neuron loss was measured by Nissl staining. RESULTS: TGF-β₁ reduced the average frequency, severity and duration of spontaneous seizures. The activated glia cells in the hippocampus were significantly reduced in TGF-β₁ group compared with pilocarpine group at 14 days after SE (P<0.05). TGF-β₁ significantly attenuated the loss of pyramidal neurons in hippocampal CA3 area at 14 days after SE (P<0.01). CONCLUSION: Intranasal TGF-β₁ reduces spontaneous recurrent seizures by inhibiting the activation of glia cells and attenuating the loss of pyramidal neurons.