Abstract:  Objective To investigate effects of antioxidant stress protein heme oxygenase-1 （HO-1） on lipopolysaccharide （LPS）-induced endoplasmic reticulum stress （ERS） of rat hepatocytes. Methods The BRL cells （rat hepatocyte cell line） were cultured. The hepatocytes were treated with LPS, LPS+HO-1 siRNA, HO-1 siRNA and PBS solution, respectively. The cell viability was measured by trypan blue exclusion test. The apoptosis cells were detected by the fluorescent dye Hoechst 33258. Expressions of GRP78, CHOP, caspase-12 and HO-1 were detected by Western blotting. Results LPS caused an increase of HO-1 protein expression of rat hepatocytes in a dose-dependent and time-dependent manner, a up-regulation of GRP78, CHOP and caspase-12, a decrease in cell viability, and an increase in apoptosis rate of hepatocytes. Pretreatment of HO-1 siRNA inhibited the up-regulation of LPS-induced HO-1, however, aggravated ERS and cellular injury. Conclusion HO-1 inhibites ERS-mediated cellular injury of rat hepatocytes induced by LPS.

Key words: forensic pathology, RNA, small interfering, endoplasmic reticulum, stress, lipopolysaccharides, heme oxygenase-1, hepatocytes, rats