Expressions of programmed death 1 and programmed death ligand 1 in rat model of acute liver failure / 中华传染病杂志

ABSTRACT

Objective To study the expressions of programmed death 1 (PD-1) and programmed death ligand 1 (PD-L1) in liver injury of acute liver failure (ALF) in rats and the role of PD-1/ PD-L1 in liver inflammatory injury. Methods SD rats were divided into two groups 6 in normal group and 30 in ALF model group. The ALF models in rats were induced by D-galactosamine (D-Gal). The sera and hepatic tissue samples were collected at 12, 24, 48, 72 and 120 hours after D-Gal injection. Expressions of PD-1 mRNA and PD-L1 mRNA in hepatic tissue samples were detected by reverse transcription-polymerase chain reaction (RT-PCR). Comparison of measurement data between groups was done by t test. Correlation test was performed using Pearson linear correlation analysis. Results The levels of alanine animotransferase (ALT) and aspartate animotransferase (AST) at 12 h of D-Gal injection were (217. 3±33. 7) U/L and (397. 2± 101.3) U/L, respectively,which were both significantly higher than those in normal group [(30. 5 ±3. 1) U/L and (78. 6±4.2) U/L, respectively; t=-8. 921 and -6. 121, respectively; both P＜0.01] and peaked at 48 h.The expression of PD-1 mRNA in model group at 12 h (0. 385±0. 074) was significantly higher than that in normal group (0. 097±0.009) (t= -7. 725, P＜0.01) , and peaked at 48 h (0. 927±0. 132),then decreased obviously at 72 h. The expression of PD-L1 mRNA in the liver tissue of normal rats was very little, while that in model group was increased gradually over time, then peaked at 48 h (0. 593±0. 105; t =- 10. 076, P＜0. 01). The expressions of PD-1 and PD-L1 were positively correlated with ALT level (r=0. 807 and 0. 792, respectively; both P＜0. 01). Conclusion The expressions of PD-1/PD-L1 may play an important role in liver inflammatory injury in rat model of acute liver failure.