Effect of nuclear factor-E2-related factor 2 signal pathway on the heme oxygenase-1 against ethanol-induced osteoblast damage

Abstract

Objective To find the mechanism of the heme oxygenase-1 (HO-1) against ethanol-induced osteoblast damage, and clarify the effect of nuclear factor-E2-related factor 2 (Nrf-2)/antioxidant response element (ARE) signal pathway on the protective effect of HO-1, to provide theoretical support for the later research and the clinical application of biological agent of HO-1. Methods The osteoblast cells were isolated and cultured, then HO-1 was transfected using Lipofectamine 2000. After cells were exposed to ethanol for 24 h, the levels of Nrf-2 and HO-1 were measured by Western blotting. The enzyme activity of myeloperoxidase (MPO) and glutathione peroxidase (GSH-Px) were tested using the corresponding kits. Results The enzyme activity of MPO and GSH-Px was respectively (54.17±20.61) mU/mg prot and (7.94±2.42) U/mg prot in the positive group, which was significantly decreased (P=0.023, 0.012) as compared with that in the negative group. The enzyme activity of MPO and GSH-Px was significantly increased to (286.54±13.82) mU/mg prot and (38.59±5.30) U/mg prot (P=0.000, 0.000) in HO-1 group as compared with that in the negative group and positive group. The Nrf-2 and HO-1 levels (respectively 0.27±0.08 and 0.81±0.05) were significantly decreased than those in the positive group (respectively 0.62±0.11 and 1.26±0.20, P=0.016, 0.003), but Nrf-2 and HO-1 were all significantly increased in the HO-1 group(respectively 0.94±0.10, 2.43±0.13; P=0.000, 0.000). Conclusion The protective effect of HO-1 against ethanol-induced osteoblast damage was related to Nrf-2/ARE signal pathway, which could activate and enhance the celluar antioxidant ability to reduce the damage of the osteoblast cells induced by alcohol. Key words: Heme oxygenase-1; Osteoblast; Nuclear factor-E2-related factor 2; Myeloperoxidase; Glutathione peroxidase