FIG. 5.

pMEX are readily taken up by cells and induce proliferation. (A) 100 μg pMEX were fluorescently labeled with the lipophilic dye, PKH26, washed, and then exposed to SHSY5Y cells for 1 h, and evaluated via fluorescent microscopy with a 4× objective. SHSY5Y cells costained with Hoechst 33342. (B, C) Quantification of pMEX uptake by SHSY5Y's was determined using flow cytometry analysis of SHSY5Y exposed to 100 μg CellMask Green fluorescent labeled pMEX for 1 h, compared to CellMask Green “labeled” PBS controls. (D–F) Treatment of serum-deprived SHSY5Y cells with 100 μg pMEX for 18 h induced proliferation as determined by CCK8 colorimetric assay followed by fluorescent microscopy of Hoechst 33342-stained cells. (G, H) Following 18 h serum deprivation, SHSY5Y's were treated with 100 μg pMEX and assessed for proliferation 18 h posttreatment with flow cytometry analysis of FITC-labeled Edu compared with vehicle (PBS) controls. (I, J) SHSY5Y's were treated with 100 μg pMEX or vehicle controls (PBS), in the presence or absence of 10 mM AKT-specific inhibitor (PHT427) and proliferation was evaluated using Edu-FITC assay. (K, L) SHSY5Y's were treated with 100 μg pMEX or vehicle control (PBS), in the presence or absence of 100 μM R-G-D-S peptide inhibitor and proliferation was assessed using Edu-FITC assay. All proliferation studies were performed three times to verify reproducibility n = 3, T test analysis was used to test for significance, *P < 0.05, **P < 0.01, ***P < 0.005. PBS, phosphate-buffered saline.