Src regulates Rac1-dependent microglial phagocytosis through PI3K/Akt pathway. (A) LPS-activated BV-2 cells pretreated with or without PP1 (10 μM), wortmannin (100 nM), or API-2 (5 μM), followed by LLLT (20 J/cm2) treatment. Cells stably transfected with GFP-FRNK were also collected for LPS stimulation and LLLT treatment. Western blot analysis of the treated cells was performed to detect GTP-Rac1 and total Rac1 at 10 min. Data were the representative graph. (B) Quantitative analysis of the levels of GTP-Rac1 and total Rac1 in treated cells. Data represent mean ± SEM (n = 4; *P <0.05 versus control cells,). (C) LPS-activated BV-2 cells pretreated with or without PP1, wortmannin, or API-2, followed by LLLT (20 J/cm2) treatment. The levels of phospho-Thr308-Akt, phospho-Ser473-Akt, and total Akt were detected with western blot analysis at indicated times. (D) Quantitative analysis of the levels of phospho-Thr308-Akt and phospho-Ser473-Akt in treated cells. (n = 4; *P <0.05 and **P <0.05 versus corresponding control cells, #P <0.05 versus indicated cells). (E and F) LPS-activated microglial cells pretreated with or without wortmannin, API-2, or SMT (100 μM) for 1 h, followed by LLLT (20 J/cm2) treatment. (E) Total F-actin in primary microglia was stained using FITC-phalloidin at the indicated times and measured as described in Materials and Methods. Data represent mean ± SEM (n = 6). (F) Fluorescent images of the distinct microglial phagocytosis in BV-2 cells. Merged beads (red) and F-actin (green) are displayed in yellow (bottom). Images shown are representative of approximately 100 cells. Bar = 10 μm. LLLT, low-level laser therapy; LPS, lipopolysaccharide.