FIG 7.

DiI-Labeled PC12 cells co-cultured with young adult astrocytes for 6 days exhibited increased levels of TGFβ1 as compared to co-cultures with reproductive senescent astrocytes. NGF-induced neuronal differentiation of PC12 cells significantly increased the protein expression of TGFβ1 (a). An increase in TGFβ1 protein expression was also observed when PC12 cells were co-cultured with young adult astrocytes but not when PC12 co-cultured with reproductive senescent astrocytes or in astrocyte only cultures (b). 0 indicates that no detectable level of TGFβ1 was observed. Bars represent mean ± SEM of a single representative experiment with n=3-5 for each treatment group. Statistical significance at p< 0.05 is indicated by (*, **). Bar: 50 μm.