Bcl-2 accelerates the neuronal differentiation: new evidence approaching to the biofunction of bcl-2 in the neuronal system.

The proto-oncogene product Bcl-2 is unique in that it inhibits apoptosis rather than promoting cell proliferation. In the present study, we encountered a new possible role of Bcl-2 in the neuronal differentiation. Rat pheochromocytoma PC12 cells have been known as the model of neuronal differentiation by the stimulation of NGF. Bcl-2 transfected PC12 (MB2) cells showed the accelerated neuronal differentiation, as compared with control PC12 (V4) cells. In addition, chemotherapeutic agents Taxol which has been known as neurotoxic compound, induced the acute neuronal cell atrophy and suppressed neuronal differentiation. This neuronal cell atrophy and suppression of neuronal differentiation were not due to apoptotic cell death. Interestingly, Bcl-2 rescued PC12 cells from both neuronal cell atrophy and suppression of neuronal differentiation. Taxol suppressed polymerization between neurofilament light and heavy (NF-L and NF-H), and MB2 cell extract rescued it. We, therefore, suggest the acceleration of polymerization between NF-L and NF-H as the new possible role of Bcl-2. Copyright 1998 Elsevier Science B.V.