Figure 4. The neuroprotective effect of the GPNMB extracellular fragment against SOD1^G93A with serum free stress-induced cell death was blocked by NKA inhibitors.

Cells were treated with vehicle or with human recombinant GPNMB (2.5 μg/ml), along with NAK inhibitors, (A) ouabain (10 μM) and (B) sanguinarine (0.3 μM), concomitantly with removing the serum. The number of cells displaying PI or Hoechst 33342 fluorescence was counted, and the cell death rate was expressed as the ratio of PI-positive cells to Hoechst 33342-positive cells. ^##p < 0.01 vs. control group (Student’s t-test). **p < 0.01 vs. Vehicle group, ^††p < 0.01 vs. GPNMB group (Student’s t-test). Each column and bar represents the mean ± S.E.M. (n = 4). Scale bar = 50 μm.