Protective effect of heme oxygenase-1 overexpression on acute necrotizing pancreatitis rat model

Objective To observe the effect of up-regulating Heme oxygenase-1(HO-1)expression in acute necrotizing pancreatitis(ANP) rats and to investigate its potential mechanism. Methods A total of 63 male healthy Sprague-Dawley(SD) rats were treated by retrograde injection of 5% sodium taurocholate into pancreatic duct to establish ANP model. ANP rats were randomly divided into ANP group, Adenoviral empty vector(Adv-0) group and Adenoviral carriging HO-1 gene(Adv-Ho-1) group with 21 rats in each group. Adv-0 and Adv-HO-1 were constructed by Virus and Gene Therapy Center, Eastern Hapatobiliary Surhery Hospital. In ANP group, 1ml normal saline solution per animal was intraperitoneally injected at 30 minutes after the establishment of model; in Adv-0 group, 2.0×109 pfu/mL Adv-0 per animal was intraperitoneally injected; in Adv-HO-1 group, 2.0×109 pfu/mL Adv-HO-1 per animal was intraperitoneally injected. 15 rats in each group were used to observe the survival rate for 72 hours and the other 6 rats in each group were executed at 20 hours after the establishment of ANP model to detect serum HO-1, IL-10 and TNF-α level. Pancreatic tissue was collected and the histopathological changes were observed. HO-1, IL-10 and TNF-α mRNA level in pancreatic tissue were detected by real-time PCR. Results At 20 hours after ANP model establishment, serum HO-1 level in ANP group, Adv-0 group and Adv-HO-1 gene group was (0.90±0.09), (0.89±0.07) and(1.29±0.07)μg/L; serum IL-10 was (85.68±5.61), (81.11±2.48) and(120.93±8.07)ng/L; serum TNF-α was (47.77±6.54), (50.08±6.60) and (28.07±2.98)ng/L. HO-1 mRNA expression in pancreatic tissue in each group was 160.44±11.47, 158.23±10.51 and 237.25±12.09; IL-10 mRNA expression was 33.93±2.56, 34.13±3.01 and 60.02±2.89; TNF-αmRNA expression was 25.23±2.37, 25.03±2.07 and 13.12±1.77. The serum level and mRNA expression of HO-1 and IL-10 in Adv-HO-1 gene group were both significantly higher than those in ANP group and Adv-0 group, while TNF-αl level and mRNA expression were decreased, indicating that the differences were statistically significant(P 0.05). At 72 hours after ANP model establishment, the survival rate in ANP group, Adv-0 group and Adv-HO-1 group was 6.67%, 0 and 46.67%. The survival rate of Adenoviral HO-1 gene group was significantly higher than that of ANP group and Adv-0 group, and the difference was statistically significant(P 0.05). Conclusions Adenoviral transfection of HO-1 gene can up-regulate HO-1 expression, which could exert protective effects on ANP rats. The potential mechanism might be associated with up-regulating IL-10 and down-regulating TNF-α. Key words: Pancreatitis, acute necrotizing; Heme oxygenase-1; Transfection; Tumor necrosis factor-alpho; Interleukin-10