PPARδ activation protects H9c2 cardiomyoblasts from LPS‑induced apoptosis through the heme oxygenase‑1‑mediated suppression of NF‑κB activation.

Abstract

The aim of the present study was to investigate the protective effect of the selective peroxisome proliferator-activated receptor δ (PPARδ) agonist GW501516 (GW) on lipopolysaccharide (LPS)‑induced apoptosis in the rat cardiomyoblast cell line H9c2, and to investigate the possible underlying mechanisms. Cell viability was estimated using the MTT assay. Apoptosis was estimated by flow cytometry using Annexin V‑fluorescein isothiocyanate/propidium iodide staining and caspase‑3 activity assay. The protein level of heme oxygenase‑1 (HO‑1), cleaved caspase‑3 (CC3), apoptosis regulator Bcl‑2 (bcl‑2), apoptosis regulator BAX (bax) and nuclear factor‑κB (NF‑κB) p65 was measured by western blot analysis. The results demonstrated that pretreatment with GW inhibited the LPS‑induced increase in the rate of apoptosis. Pretreatment with GW also increased the bcl‑2/bax ratio, and decreased CC3 protein expression as well as caspase‑3 activity, in LPS‑stimulated H9c2 cells. Further studies demonstrated that GW inhibited LPS‑induced NF‑κB nuclear translocation in a dose‑dependent manner. In addition, GW induced HO‑1 protein expression in a dose‑dependent manner. ZnPP‑IX, an inhibitor of HO‑1, reversed the inhibitory effect of GW on LPS‑induced NF‑κB activation, leading to the attenuation of PPARδ‑mediated apoptosis resistance. In conclusion, these results suggest that PPARδ activation exerts an anti‑apoptotic effect in LPS‑stimulated H9c2 cardiomyoblasts, potentially through heme oxygenase‑1‑mediated suppression of NF‑κB activation. PPARδ appears to be a promising therapeutic target for the treatment of sepsis‑associated cardiac dysfunction.