Fig. 6. RGMa enhanced entry of mutant SOD1 protein into rat primary cortical neurons via F-actin reduction in vitro.

RGMa and jasplakinolide were added to the rat primary neuron culture to evaluate the entry of rSOD1 proteins into the neurons. (A) Recombinant human WT SOD1 protein (rSOD1^WT), recombinant human SOD1 protein with G93A mutation (rSOD1^G93A), or one with A4V mutation (rSOD1^A4V) labeled with FLAG was administered to rat primary neurons treated with or without RGMa and inoculated with jasplakinolide or DMSO. The rSOD1 protein was visualized using an anti-FLAG antibody conjugated to FITC. Representative images are shown. (B) Quantification of mean FITC intensity in rat primary neurons is shown in (A). Each filled dot indicates the mean FITC intensity of a single FITC-positive cell. In all the conditions, 36 cells selected from three individual wells were measured (Data are representative of two individual experiments). Scale bars, 20 μm. Error bars indicate the mean ± SEM.