Glial fibrillary acidic protein is one of the key factors underlying neuron-like elongation in PC12 cells.

Nerve growth factor (NGF) normally induces the differentiation of PC12 cells into a neuron-like phenotype. In this study, we found that exposure of PC12 cells to a temperature of 42°C for 24 h significantly decreased NGF-induced neurite elongation. Glial fibrillary acidic protein (GFAP) levels were decreased when PC12 cells were exposed to the heat stress, while PC12 cells overexpressing the gene encoding GFAP showed resistance. Mock-transfected PC12 cells exposed to NGF could be cultured for 72 h at 37°C, whereas GFAP-transfected PC12 cells exposed to NGF could be cultured for over 100 h. Our results suggest that GFAP is necessary for the long-term maintenance of cells with a neuron-like phenotype.