Fig. 7.

Expression of SEKAL does not prevent NGF withdrawal-induced death or the increase in c-Jun protein levels that occurs after NGF withdrawal. A, Expression of SEKAL does not protect sympathetic neurons against NGF withdrawal-induced death. Neurons were injected with pcDNA1 (0.05 mg/ml), pCDBcl-2 (0.05 mg/ml), pSG5 (0.4 mg/ml), or the SEKAL vector (0.4 mg/ml) together with Texas Red–dextran. pcDNA1 and pSG5 were control vectors for pCDBcl-2 and SEKAL, respectively. After injection, the cells were deprived of NGF. Seventy-two hours later, the percentage of viable injected neurons was determined as described in Materials and Methods. The results shown are the average of three independent experiments. Error bars indicate SE. B, SEKAL does not inhibit expression of c-Jun protein after NGF withdrawal. Sympathetic neurons were injected with pCDFLAGΔ169 (0.2 mg/ml), the SEKAL expression vector (0.4 mg/ml), or the empty vector pSG5 (0.4 mg/ml) together with guinea pig IgG at 5 mg/ml. After injection, the cells were withdrawn from NGF. Twenty-four hours later, the percentage of injected cells that expressed c-Jun was determined as described in Materials and Methods. c-Jun expression in uninjected cells on the same coverslips was scored for comparison. Only cells in which nuclear staining with the c-Jun antibody was more intense than the background cytoplasmic staining were considered to be expressing c-Jun. Two hundred cells were injected per construct. The data shown are the average of three independent experiments. Error bars indicate SE.