Resolvin D1 reduces the toxic effects of active BV-2 microglial cells to PC12 cells

Abstract

Objective To investigate the effects of Resolvin D1 (RvD1) on lipopolysaccharide (LPS)-induced BV-2 microglial cells activation and neuron-like PC12 cells apoptosis through suppressing activated BV-2 microglial cell-mediated inflammatory reaction. Methods BV-2 microglial cells were divided into four groups: control group, LPS group, RvD1+ LPS group and RvD1group. BV-2 cells in each group were incubated with corresponding drugs for 24 h. The PC12 cells in each group were incubated with corresponding BV-2 cells culture supernatant for 24 h. The apoptotic PC12 cells were observed by 4', 6-diamidino-2-phenylindole (DAPI) staining. The survival rate of PC12 cells was tested by cell counting kit (CCK-8) assay. The apoptosis rate of PC12 cells was examined by Annexin V-fluoresceine isothiocyanate (FITC)/propidium iodide (PI) apoptosis detection kit. The BV-2 cells culture supernatants were collected after incubating with corresponding drugs for 24 h, and the concentrations of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) were determined by enzyme linked immunosorbent assay (ELISA). Results Compared to the control group, the PC12 cells presented evident apoptosis features and the cells survival rate (100.00% vs. 84.93%) was significantly reduced (P<0.05) and the apoptosis rate (5.12% vs. 14.42%) was significantly increased (P<0.05) in LPS group. The concentrations of IL-1β, IL-6, and TNF-α [(45.68±4.80) pg/ml vs. (297.97±16.14) pg/ml, (26.97±4.44) pg/ml vs. (297.46±14.21) pg/ml, (80.12±9.34) pg/ml vs. (920.63±25.56) pg/ml]were significantly increased (P<0.05) in LPS group. As compared with the LPS group, the apoptosis of PC12 cells was significantly reduced, the cells survival rate (91.60% vs. 84.93%) was significantly increased (P<0.05) and the apoptosis rate (8.51% vs. 14.42%) was significantly reduced in RvD1+ LPS group. The concentrations of IL-1β, IL-6, and TNF-α [(114.47±9.65) pg/ml vs. (297.97±16.14) pg/ml, (111.10±9.57) pg/ml vs. (297.46±14.21) pg/ml, (320.66±18.21) pg/ml vs. (920.63±25.56) pg/ml)]were significantly reduced (P<0.05) in RvD1+ LPS group. Conclusion RvD1 could reduce the toxic effects of activated BV-2 microglial cells on PC12 cells through reducing activated BV-2 microglial cell-mediated inflammatory factor levels. Key words: Resolvin D1; Lipopolysaccharide; Microglial cells; Inflammation