Antisense Oligodeoxynucleotide Dependent Suppression of Acetylcholinesterase Expression Reduces Process Extension from Primary Mammalian Neurons

The only currently approved drugs for Alzheimer’s disease (AD) are potent blockers of acetylcholinesterase (AChE) activity (Knapp et al., 1994). However, several lines of evidence suggest novel, non-catalytic morphogenic properties of AChE in process extension (Small et al, 1995; Layer and Willbold, 1995; Jones et al., 1995; Darboux et al., 1996; Sternfeld et al., 1997) and amyloid fibril formation (Inestrosa et al, 1996). This calls for the development of alternative approaches in which both AChE protein synthesis and enzymatic activity would be suppressed, such as the “antisense”.technology (Grifman et al., 1997). To this end, we have designed seven synthetic 3′-phosphorothioatedoligonucleotides (AS-ODNs) targeted towards AChEmRNA and tested their AChE suppression efficacies on the rat neuroendocrine pheochromocytoma cell line, PC 12. Two of these AS-ODNs suppressed the catalytic activity of AChE in nerve growth factor (NGF) -treated PC 12 cells by 25–35%, significantly more than the parallel suppression by control ODNs (Grifman and Soreq, 1997). To study the involvement of AChE in neurite outgrowth and differentiation of primary neurons, we added these two AS-ODNs to primary neuronal cultures from embryonic (El4) mouse whole brain.