Figure 5. miR-21 regulates astrogliosis through the PI3K/Akt/mTOR signaling pathway. Western blot was performed to examine changes in the expression of key proteins in the PI3K/Akt/mTOR signaling pathway; an Akt signaling inhibitor was used to confirm results. Two groups were examined: one treated with TGF-β1 in addition to transfection with miR-21 KD or NC, and a second transfected with miR-21 OE or NC alone. (A) PTEN, PI3K, p-Akt, Akt, p-mTOR, GAPDH were examined (n = 5). (B–K) Results were analyzed by ImageJ and SPSS. Data are expressed as mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001 compared with NC group. (L) Two groups were analyzed: one transfected with miR-21 OE or NC with or without LY294002; and a second treated with TGF-β1 or PBS with or without LY294002. p-Akt, Akt, p-mTOR and GAPDH were examined by western blot (n=5). (M–P) Results were analyzed by ImageJ and SPSS. Data are expressed as mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001. Akt, protein kinase B; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; miR, microRNA; miR-21 KD, LV-mmu-miR-21a-inhibition; miR-21 OE, LV-mmu-miR-21a; mTOR, mechanistic target of rapamycin; NC, negative control; PBS, phosphate-buffered saline; PI3K, phosphoinositide 3-kinase; PTEN, phosphatase and tensin homolog deleted on chromosome ten; SD, standard deviation; TGF-β1, transforming growth factor beta 1.