Adiponectin Protects against Glutamate-Induced Excitotoxicity via Activating SIRT1-Dependent PGC-1 Expression in HT22 Hippocampal Neurons

Figure 2

Protective effects of the APN peptide against Glu-induced injury in HT22 cells. (a) Cells were pretreated by the APN peptide with the mentioned concentrations above for 6 h and then exposed to 5 mM Glu for 24 h. Cell viability is shown in OD. (b) LDH release is expressed as fold increase of the control levels. (c) Cell images were taken using a light microscope. Cells shrank and showed decreased cell junctions in the Glu group but a gradual recovery following the increased concentrations of APN peptide in the APN peptide pretreatment groups. (d) HT22 cells were exposed (or not) to an APN peptide pretreatment at the indicated concentrations (100 μM, 250 μM, and 500 μM) for 6 h followed by 5 mM Glu treatment for 24 h and then stained with TUNEL and DAPI. Representative images of apoptotic neurons (400x) were shown. The apoptotic cells were detected by TUNEL (green), and the nuclei were detected by DAPI (blue). (e) The apoptosis index showed a dose-dependent decrease in cell apoptosis. (f) Cleaved-caspase-3, Bax, and bcl-2 levels were analyzed by western blotting and β-actin was used as the control protein. (g) Cleaved caspase-3 expression level. (h) Bax/Bcl-2 ratio. The data are presented as the mean ± SD. ; versus the control group; versus the Glu group; versus the 100 μM APN peptide pretreatment group; versus the 250 μM APN peptide pretreatment group. APN, adiponectin; OD, optical density; LDH, lactate dehydrogenase.

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