ABSTRACT
Objective To explore the effects of tumor necrosis factor-α induced protein 6 (TSG-6) on acute kidney injury (AKI) following paraquat poisoning in rats.Methods Twenty-four male Sprague-Dawley (SD) rats were randomly divided into sham group (n=8),model group (n=8) and TSG-6-treated group (n=8) using a randomized number table.Rats were given an injection of 50 mg/kg of paraquat intraperitoneally (total volume was equalled to sterile normal saline) in model and TSG-6-treated groups.Rats in sham group were given 2 mg/kg of sterile saline.Mter 1 hour of paraquat administration,rats were treated with 30 μg of recombinant human TSG-6 intraperitoneally in TSG-6-treated group.After 6 hours of paraquat administration,serum was collected to assess renal function,then rats were sacrificed and renal tissues were immediately harvested.AKI score was evaluated by renal histopathology and gene expression of pro-inflammatory cytokines including interleukins (IL-1β and IL-6) and tumor necrosis factor-α (TNF-α) in kidney was assayed with real-time reverse transcription-polymerase chain reaction (RT-PCR).Results Compared with sham group,blood urea nitrogen (BUN),creatinine (Cr) and AKI score were significandy increased in model group [BUN (mmoUL):22.64 ±2.36 vs.7.09 ±0.65,t=6.986,P=0.000; Cr (μmol/L):177.28 ± 18.67 vs.60.32 ± 3.11,t=7.134,P=0.000; AKI score:9.14 ± 0.28 vs.0.30 ± 0.23,t=9.013,P=0.000].Moreover,the mRNA expressions of IL-1β,IL-6 and TNF-α were significantly elevated in model group (IL-1β mRNA:3.23 ± 0.28 vs.1.00 ±0.07,t=5.874,P=0.000; IL-6 mRNA:4.16 ±0.37 vs.1.00 ±0.08,t=7.125,P=0.000; TNF-α mRNA:3.85 ±0.31 vs.1.00 ±0.10,t=6.342,P=0.000).However,serum BUN,Cr,AKI score and the mRNA expressions of IL-1β,IL-6 and TNF-α in TSG-6-treated group were significantly lower than those in model group [BUN (mmol/L):14.07 ± 5.23 vs.22.64 ± 2.36,t=2.533,P=0.026; Cr (μmol/L):112.76 ± 14.81 vs.177.28 ± 18.67,t=2.778,P=0.016; AKI score:5.35 ±0.19 vs.9.14 ±0.28,t=2.885,P=0.013; IL-1β mRNA:2.26 ± 0.19 vs.3.23 ±0.28,t=2.457,P=0.023; IL-6 mRNA:2.92 ±0.29 vs.4.16 ±0.37,t=2.975,P=0.011; TNF-α mRNA:2.58 ± 0.23 vs.3.85 ± 0.31,t=2.564,P=0.019].Conclusion TSG-6 attenuates AKI following paraquat poisoning by suppressing inflammatory response.