Lipopolysaccharide protects kidney ischemia-reperfusion injury by up-regulating heat shock protein-27 in mice / 第二军医大学学报

ABSTRACT

Objective To explore the effect of heat shock protein-27 (HSP27) in lipopolysaccharide (LPS)-induced renoprotection against ischemia-reperfusion (IR) injury in mice. Methods Male C57BL/6 mice were used for establishing renal IR injury model and the animals were divided into 4 groups sham group, LPS+sham group, IR group, and LPS+IR group; each group was further divided into quercetin (200 mg/kg) subgroup and vehicle control subgroup. Renal IR model was established by right nephrectomy + clamping the left renal pedicle for 25 min. Mice were intraperitoneally injected with LPS (3 mg/kg body weight) 3 days prior to renal IR, and the expression of HSP27 was inhibited by quercetin (200 mg/kg), an inhibitor of HSP27 synthesis. 24 h after reperfusion, the extent of IR injury was evaluated by serum creatinine (Cr) and blood urea nitrogen (BUN) levels in abdominal aorta, and the degree of inflammatory reaction, expression of HSP27 protein and activity of apoptosis protein caspase-3 were evaluated in the left kidney. Results LPS pretreatment significantly reduced the levels of Cr and BUN in the serum, improved the expression level of HSP27, and reduced the degree of renal IR injury after renal IR (P<0.05). It was found that quercetin significantly inhibited the expression of HSP27 in the kidney (P<0.05). Quercetin could significantly weaken the alleviating effect of LPS on renal IR by elevating Cr and BUN levels and causing more severe inflammation reaction (P<0.05). In addition, LPS significantly reduced the activity of caspase-3 after renal IR, which could be significantly weakened by quercetin. Conclusion LPS pretreatment can relieve the renal IR injury in mice by up-regulating the expression of HSP27.