FIGURE 5:

Hsp27 also regulates bim-3′UTR sequence during excitotoxicity. (A) CGNs were transfected with pNEO-Hsp27 or a control construct before glutamate (100 μM)/glycine (10 μM) exposure. pNEO-Hsp27–transfected neurons exhibited significantly lower Bim protein levels than control neurons after H₂O₂ treatment (*p < 0.05; n = 3). β-Actin served as loading control. (B) CGNs were cotransfected with a luciferase reporter plasmid containing the bim-3′UTR (sequence 1) and either pNEO-Hsp27 or a control construct. Glutamate/glycine (100/10 μM) exposure decreased the luciferase activity in control neurons (*p < 0.05; n = 3), whereas expression of the pNEO-Hsp27 construct significantly enhanced this effect (*p < 0.05; n = 3). (C) Cortical neurons were cotransfected with a luciferase reporter plasmid containing the bim-3′UTR (sequences 1) and either pNEO-Hsp27 or a control construct. NMDA (100 μM)/glycine (10 μM) exposure decreased the luciferase activity in control neurons (*p < 0.05; n = 3), and expression of the pNEO-Hsp27 construct significantly enhanced this effect (*p < 0.05; n = 3).