Figure 5.

Sertraline regulates glucocorticoid receptor (GR) phosphorylation, GR-mediated expression of p27^Kip1 and p57^Kip2 and GR transactivation. During progenitor cell proliferation, SERT (1 μ) decreases GR phosphorylation at S203 after 1 h of treatment, but increases S203 phosphorylation after 6 h and 12 h (a, white columns). These effects are counteracted by H89. DEX increases S203 phosphorylation after 1 h and decreases S203 phosphorylation after 6 h (a, striped columns). DEX+SERT co-treatment does not change S203 phosphorylation at 1 h, but increases S203 phosphorylation at 6 h and 12 h (a, squared columns). These effects of DEX+SERT are also abolished by H89. SERT does not change GR phosphorylation at S211 (b, white columns). DEX increases S211 phosphorylation after 1, 6 and 12 h (b, striped columns). DEX+SERT co-treatment induces hyperphosphorylation at S211, which exceeds the phosphorylation induced by DEX alone, and this effect is also abolished by H89 (b, squared columns). Western blots for the GR-phosphoisoforms S203 and S211 are shown after 1 h of treatment (a,b). SERT increased the expression of p27^Kip1 (c) and p57^Kip2 (e). The increased expression of p27^Kip1 and p57^Kip2 after 12 h of sertraline treatment was abolished by RU486 (d,f). SERT increased GR transactivation after 12 h of treatment (g), an effect which was abolished by H89 (h). S203 and S211 phosphorylation are normalized to the expression of the unphosphorylated, total GR protein. Gene expression of p27^Kip1 and p57^Kip2 is normalized to the housekeeping genes ACTB, GAPDH and B2M. All data are mean±s.e.m. ^*P<0.05, ^**P<0.01 and ^***P<0.001 compared with the respective vehicle.