Fig. 2.
Expression of CDK inhibitors andBcl-xL using the Sindbis viral delivery system promotes survival of primary cultured sympathetic neurons deprived of trophic support. Each data point is the mean ± SEM of three samples and is expressed relative to the number of neurons present in each well at the time of NGF withdrawal. Control viruses for each vector were generated by removal of the start codon and, in some cases, by introduction of a premature stop site.Flag denotes that the wild-type (WT) protein has a flag epitope attached to the C terminal. The values of p derived from Student’st tests comparing the wild-type or flagged protein with the control-stop virus at days 1 and 2 are given. A–D, Effects of overexpression of Bcl-xL(p < 0.01) (A), p16 (p < 0.05) (B), p21 (p < 0.005) (C), and p27 (p < 0.05) (D) and respective controls on the time course of survival of sympathetic neurons after withdrawal of NGF. Similar results were obtained in at least three independent experiments.