Artefactual effects of lipid-based cell transfection reagents on AbetaPP processing and Abeta production.

The study of amyloidogenic beta-amyloid precursor protein (A beta PP) metabolism and amyloid beta protein (A beta) production has been a major focus of Alzheimer's disease (AD) neuropathogenesis research. Cell transfection is a commonly employed method for assessing the effects of various genes on A beta PP processing and A beta production. Certain cell transfection reagents utilize lipid-based formulations that could potentially affect A beta PP processing and A beta production. Thus, we set out to assess the effects of cell transfection reagents with lipid formulations (TKO, FuGene6, RNAifect) on A beta PP processing and A beta level in H4 human neuroglioma cells overexpressing human A beta PP. We found both TKO and RNAifect increase the protein levels of A beta PP-C-terminal fragments (CTFs) and A beta levels, while FuGene6 increases the protein levels of A beta PP-CTFs without altering A beta level. In contrast, electroporation-based cell transfection does not affect A beta PP processing and A beta production in our studies. These results suggest for the first time that lipid-based cell transfection reagents may artefactually affect A beta PP processing and A beta production, thereby confounding studies aimed at assessing the effects of transfected genes on A beta PP metabolism.