The effects of fluoxetine and quetiapine on the proliferation and differentiation of, and GDNF release from, C6 cells
According to the literature, there is a decrease in glial cell number or hypofunction of glial cells in depression. It was also found that both antidepressants and atypical antipsychotics might target glial cells, and that they increase the release of glial-cell-line-derived neurotrophic factor (GDNF) from C6 rat glioma cells (C6 cells). In this project, C6 cells were used as a model for glial cells to investigate the effects of fluoxetine and quetiapine on proliferation and differentiation, and to investigate their effects on the release of GDNF. A combination of quetiapine and fluoxetine was used to study their potential synergistic effect on the release of GDNF from C6 cells. C6 cells were treated with different concentrations of fluoxetine and quetiapine in both normal and serum starvation culture conditions. Under the serum present condition, fluoxetine (25 mM) decreased the number of C6 cells from 24 to 48 h, while quetiapine (25 mM) decreased the cell number only at 48h. Under serum starvation, it was found that fluoxetine (12.5 mM) increased the number of C6 cells from 24 to 48 h treatment; in contrast, quetiapine (25 mM) decreased the number of C6 cells after 48 h treatment. Both fluoxetine and quetiapine inhibited the proliferation of C6 cells under normal and serum starvation conditions. Fluoxetine (12.5 mM) decreased C6 cell death, while quetiapine had no significant effect. Fluoxetine, but not quetiapine, changed the morphology of C6 cells and increased the level of glial fibrillary acidic protein (GFAP), an astrocyte marker. Both fluoxetine (12.5, 25 mM) and quetiapine (25 mM) increased the release of GDNF from C6 cells, and an apparent additive effect was found between quetiapine and fluoxetine in the modulation of release of GDNF from these cells. It was concluded that:1. High concentration (25 mM) of fluoxetine and quetiapine decreased the number of C6 cells under the serum present condition and both drugs inhibited the proliferation of C6 cells.2. Fluoxetine had a protective effect on the C6 cells under serum starvation, and affected the differentiation of C6 cells; this implies that fluoxetine may protect glial cells in vivo and affect their differentiation. 3. A high concentration of quetiapine decreased the number of C6 cells and inhibited the proliferation under serum starvation; even though it increased the release of GDNF from C6 cells as did fluoxetine.4. Both quetiapine and fluoxetine increased the release of GDNF from C6 cells under serum starvation. The combination of quetiapine and fluoxetine had an apparent additive effect in the modulation of GDNF release.5. These effects on proliferation & GDNF release may underlie the benefit observed with these drugs in treating depression and schizophrenia.
DegreeMaster of Science (M.Sc.)
SupervisorDyck, Lillian E.
CommitteeTuchek, John M.; Mousseau, Darrell D.; Li, Xin-Min
Copyright DateApril 2006
GDNF quetiapine fluoxetine C6 cells