Ghrelin inhibits high glucose-induced PC12 cell apoptosis by regulating TLR4/NF-κB pathway

Ghrelin has a protective effect on diabetic encephalopathy. To expound the protective mechanism, we investigated the effects of ghrelin on high glucose-induced cell apoptosis and intracellular signaling in cultured PC12, which is a suitable model for studying neuronal cell death. High glucose-induced PC12 apoptosis was significantly inhibited by co-treatment of ghrelin. Sustaining inflammatory response is one of the molecular mechanisms of diabetic encephalopathy and TLR4 signaling has close relationship with inflammatory response. But there is no report about the biologic role of toll-like receptor 4/nuclear factor-κB (TLR4/NF-κB) signaling in controlling high glucose-induced PC12 apoptosis by ghrelin. In this study, we found that TLR4/NF-κB pathway was activated by high glucose stimulation in PC12 and significantly alleviated by the co-treatment of ghrelin. From these findings, we made the conclusion that ghrelin could attenuate the symptoms of diabetic encephalopathy, which alleviates inflammatory reaction of diabetic encephalopathy by regulating TLR4/NF-κB pathway.