Resveratrol inhibits β-amyloid-induced neuronal apoptosis via regulation of p53 acetylation in PC12 cells

Abstract

The natural product resveratrol possesses diverse biological activities, including anti‑inflammatory, anti‑oxidant, anti‑cancer and anti‑aging effects in multiple organisms. The neuroprotective role of resveratrol has recently been reported in a cell model of amyloid (A)β(25‑35)‑induced neurotoxic injury using PC12 cells. However, the pathomechanism by which resveratrol inhibits neuronal apoptosis has remained to be elucidated. The present study therefore aimed to confirm the neuroprotective effects of resveratrol in an Aβ(25‑35)‑induced model of neurotoxicity in PC12 cells and elucidate the mechanisms underlying these effects. It was demonstrated that resveratrol exerted neuronal protection through inhibition of cell apoptosis, which was associated with an increased acetylation level of p53. In accordance with this effect, when the acetylation level of p53 was decreased by p53 acetylation inhibitor pifithrin‑α, the protective effects of resveratrol were abrogated. In conclusion, it was revealed that resveratrol inhibited Aβ(25‑35)‑induced cell apoptosis via the acetylation of p53 in PC12 cells.

Figure 1

Resveratrol prevents Aβ(25–35)-induced apoptotic cell death in PC12 cells. (A) Flow cytometry was used to examine the effects of resveratrol on Aβ(25–35)-induced cell apoptosis. In each image, the lower left quadrant area indicates the survival of cells, the lower right quadrant indicates the level of early-stage apoptosis and the upper right quadrant indicates the level of late-stage apoptosis. (B) A CCK-8 assay was used to evaluate cell viability. Resveratrol inhibited Aβ(25–35)-induced cell apoptosis. Values are presented as the mean ± standard error of the mean of three independent experiments. ^*P<0.05 between the Aβ(25–35) injury group and the revesterol + Aβ(25–35) group. DMSO, dimethyl sulfoxide; FITC, fluorescein isothiocyanate; Aβ, β amyloid.

Figure 2

Resveratrol inhibits apoptotic inducers and promotes apoptotic inhibitors in PC12 cells. (A) Cell growth and morphology of each group. Cells receiving Aβ(25–35) treatment presented retracted neurites and decreased cell confluence due to loss of cells (lower left and right panels). Resveratrol-treated cells presented recovered neutites and cell growth confluence (right upper and right lower panels). (B) Resveratrol treatment inhibited the apoptotic inducers, Bax and caspase-3, and the apoptotic inhibitor, Bcl-2, in PC12 cells. Aβ, β amyloid; DMSO, dimethyl sulfoxide; Bcl-2, B-cell lymphoma-2 protein; Bax, Bcl-2-associated protein.

Figure 3

Inhibition of apoptosis by resveratrol is associated with an increase in p53 acetylation levels. Expression levels of ERK, Akt and p53, as well as their common translational modifications were detected. ac-p53 levels were recovered and increased markedly following resveratrol treatment by comparing ac-p53 levels in the resveratrol + Aβ(25–35) group with those in the Aβ(25–35) group. DMSO, dimethyl sulfoxide; pERK, phosphorylated extracellular-signal-regulated kinases; ac-P53, acetylated p53; Aβ, β amyloid.

Figure 4

Inhibition of p53 acetylation abrogates resveratrol-mediated apoptosis inhibition. Pifithrin-α treatment was used to inhibit acetylation of p53 and resulted in attenuation of resveratrol-inhibited apoptosis. Resveratrol treatment promoted cell growth with natural neurites and adequate cell confluence (middle images). However, pifithrin-α treatment resulted in cell death with retracted neurites and damaged cell growth confluence (bottom images).