Figure 1

RPE-CM protect SH-SY5Y cells from injury in the presence of neurotoxins. (A) SH-SY5Y cells cultured without rotenone (Control), cells treated with 10 μM rotenone (Re), cells treated with 10 μM rotenone in RPE-CM (CM+Re) were examined by MTT assay. Rotenone treatment produce significant cell lose in SH-SY5Y cultures (**p < 0.01 compared with control). RPE-CM significantly attenuated rotenone-induced cell loss (##p < 0.01 compared with rotenone group). (B) SH-SY5Y cells were treated as in A in the presence of 50 μM 6-OHDA. 6-OHDA treatment produced significant cell lose in SH-SY5Y cultures (**p < 0.01 compared with CM treated control). RPE-CM significantly attenuated 6-OHDA-induced cell loss (## p < 0.01 compared with 6-OHDA treated group). (C) Blockage of GDNF and BDNF by antibodies inhibited the protection of the RPE-CM. RPE-CM was pretreated with 1 μg/ml GDNF antibody (Re+GDNFab+CM) or with 1 μg/ml BDNF antibody (Re+BDNFab+CM) and incubated with SH-SY5Y cells in the presence of 10 μM rotenone. The protective effect of RPE-CM could be partially blocked by GDNF and BDNF antibodies (*p < 0.05 compared with CM treated group). (D) Cells were treated as in C in the presence of 50 μM 6-OHDA. The protective effect of RPE-CM could be partially blocked by GDNF and BDNF antibodies when treated with 6-OHDA (*p < 0.05 compared with CM treated group; **p < 0.01 compared with CM treated control). Data showed the mean ± SEM values from three independent experiments performed in triplicate.