Fig. 8.

NT-stimulated proliferation of human microglia depends on mTOR signaling and is inhibited by Lut and Methlut. (A) HM-SV40 (5 × 10³ cells per well for 48 h or 10 × 10³ cells per well for 24 h) were stimulated with NT (10 or 100 nM) in phenol-free medium, and proliferation was measured using the MTT-based assay. Absorbance of converted dye was measured at a wavelength of 570 nm with background subtraction at 690 nm; cell proliferation was calculated with control cells set at 100%. (B) Microglia (5 × 10³ cells per well) were pretreated with the dual PI3K/mTOR (PF, 0.5 μM) and the mTOR (Rap and KU, 0.5 μM) inhibitors or the flavonoids (Lut and Methlut, 5 μM) for 2 h and then stimulated with NT (10 nM) for 48 h, and an MTT assay was performed. All conditions were done in triplicate for each dataset and were repeated three times (n = 3). Results are expressed as the percentage (%) of cell proliferation relative to the control cells, with significance of comparisons determined for control and stimulated cells, as denoted by *P < 0.05 or **P < 0.001. Multiple comparisons were also made for stimulated cells and for those cells with inhibitors/flavonoids, as denoted by the horizontal lines (P < 0.001 or P < 0.0001), and also among each of the inhibitor/flavonoid treatments shown by the horizontal brackets and by corresponding *P < 0.05 and **P < 0.001.