Apoptosis prevention in neuronally differentiated PC12 cells, by bcl-2 gene transfection in the non- proliferative and differentiated state, with retention of neuron-specific proteins and blockage of mitocondrion-relayed apoptotic pathway

摘要

Transfected bcl-2 genes are known to inhibit apoptosis in proliferative or stable transfectants, but have been scarcely scrutinized in neuronally differentiated cells that are transiently transfected in the non-proliferative and differentiated state. In the present study, NGF-differentiated PC12 cells were transiently transfected with cDNA encoding human bcl-2 wrapped by HVJ virus-based liposomes. The resultant >50-fold Bcl-2 overexpression prevented NGF-removal-induced cell death, as shown by repression of either the diminished mitocondrial tetrazolium-reducing function or the augmented DNA-3’-OH cleavage terminals, through blockages of apoptosis- associated events such as lowered mitochodrial membrane potentials, release of cytochrome c and activation of caspase-3, together with transiently repressed intracellular ROS. Overexpressed Bcl-2 could also inhibit NGFremoval-induced neurite-retraction, and the decreased levels of neurofilaments and neuron-specific enolase.