Application of Sirna Technology to Manipulate Factors Involved in Acetylcholine Exocytosis and Botulinum Toxicity

We demonstrated that the RhoB signaling pathway, regulates ACh release via actin cytoskeletal reorganization and that botulinum toxin type A (BoNT) inhibits neuroexocytosis by targeting the RhoB pathway in nerve growth factor-differentiated PC12 cells. To confirm these facts, small interfering RNA (siRNA) was used to knockout the expression of RhoB. Transfection of PC12 cells by the siRNA resulted in about 70% reduction of both mRNA and RhoB expression. This siRNA-induced RhoB suppression totally inhibited ACh release actin reorganization. The results of these studies strongly suggest that RhoB is involved in ACh exocytosis, likely that RhoB is a target of BoNT.