Nucleofection of rat pheochromocytoma PC-12 cells with human mutated beta-amyloid precursor protein gene (app-sw) leads to reduced viability, autophagy-like process, and increased expression and secretion of beta amyloid

Abstract

Pheochromocytoma PC-12 cells are immune to physiological stimuli directed to evoke programmed cell death. Besides, metabolic inhibitors are incapable of sensitizing PC-12 cells to extrinsic or intrinsic apoptosis unless they are used in toxic concentrations. Surprisingly, these cells become receptive to cell deletion after human APP-sw gene expression. We observed reduced cell viability in GFP vector + APP-sw-nucleofected cells (drop by 36%) but not in GFP vector - or GFP vector + APP-wt-nucleofected cells. Lower viability was accompanied by higher expression of A β 1-16 and elevated secretion of A β 1-40 (in average 53.58 pg/mL). At the ultrastructural level autophagy-like process was demonstrated to occur in APP-sw-nucleofected cells with numerous autophagosomes and multivesicular bodies but without autolysosomes. Human APP-sw gene is harmful to PC-12 cells and cells are additionally driven to incomplete autophagy-like process. When stimulated by TRAIL or nystatin, CLU protein expression accompanies early phase of autophagy.