Functional role of MicroRNA-19b in acinar cell necrosis in acute necrotizing pancreatitis.

The expression of microRNA-19b (miR-19b) in acute necrotizing pancreatitis (ANP) and its functional role in acinar cell necrosis of SD rats were investigated. Twelve SD rats were divided into two groups randomly, including control group and ANP group. The rat ANP models were established by intraperitoneal injection of L-arginine (2400 mg/kg body weight), and equal volume of 0.9% NaCl was injected in the control group. MiRNA chip assay was performed to examine the expression of miRNAs in the pancreas in two different groups. Besides, to further explore the role of miR-19b in ANP in vitro, taurolithocholic acid 3-sulfate disodium salt (TLC-S) (200 μmol/L) was administrated to treat the rat pancreatic acinar cell line, AR42J, for establishing the ANP cells model. The quantitative real-time PCR (qRT-PCR) was adopted to measure the miR-19b expression. Moreover, the mimic miRNA, miRNA antisense oligonucleotide (AMO) and control vector were used to transfect AR42J cells, the expression of miR-19b was confirmed by qRT-PCR and the necrotizing rate of AR42J cells was detected with AO/EB method. The expression of miR-19b was significantly higher in ANP group than in control group as displayed by the miRNA chip assay. Furthermore, after inducing necrosis of AR42J cells in vitro, the expression of miR-19b was significantly increased by 2.51±0.14 times in comparison with the control group. As revealed by qRT-PCR assay, the expression of miR-19b was 5.94±0.95 times higher in the mimic miRNA group than in the control vector group, companied with an obviously increased acinar cell necrotizing rate (50.3%±1.5% vs. 39.6%±2.3%, P<0.05). Moreover, the expression of miR-19b in the miRNA AMO group was 0.38±0.15 times lower than in the control vector group, and the cell necrosis rate was much lower accordingly (23.1%±3.3% vs. 39.6%±2.3%, P<0.05). Besides, there was no significant difference between the control vector cells and the cells without treatment (P>0.05). The expression of miR-19b was significantly induced in ANP. In addition, up-regulation of miR-19b could promote the necrosis of pancreatic acinar cells and miR-19b deficiency could decrease the rate of pancreatic acinar cell necrosis.