Effects of activated ACM on expression of signal transducers in cerebral cortical neurons of rats

Abstract

To explore the roles of astrocytes in the epileptogenesis, astrocytes and neurons were isolated, purified and cultured in vitro from cerebral cortex of rats. The astrocytes were activated by ciliary neurotrophic factor (CNTF) and astrocytic conditioned medium (ACM) was collected to treat neurons for 4, 8 and 12 h. By using Western blot, the expression of calmodulin dependent protein kinase (CaMK), inducible nitric oxide synthase (iNOS) and adenylate cyclase (AC) was detected in neurons. The results showed that the expression of CaMK, iNOS and AC was increased significantly in the neurons treated with ACM from 4 h to 12 h (P<0.05), and that of iNOS and AC peaked at 8 h and 12 h respectively. It was suggested that there might be some epileptogenic factors in the ACM and such signal pathways as NOS-NO-cGMP, Ca²⁺/CaM-CaMK II and AC-cAMP-PKA might take part in the signal transduction of epileptogenesis.

Keywords

astrocytic conditioned medium / neuron / calmodulin dependent protein kinase II / inducible nitric oxide synthase / adenylate cyclase / signal transduction