Effect of angiotensin 1-7 on the TLR4/NF-κB pathway in cerulein-induced pancreatic acinar cells

Objective To investigate the effect of angiotensin 1- 7 [Ang( 1- 7) ] on the TLR4 / NF- κB pathway in cerulein- stimulated pancreatic acinar AR42 J cells. Methods AR42 J cells were randomly divided into control group,model group( stimulated with 10 nmol / L cerulein),Ang( 1- 7) group( 10- 7,10- 6,and 10- 5mol / L Ang( 1- 7) + 10 nmol / L cerulein),and Ang( 1- 7) receptor inhibitor A779group( 10- 7,10- 6,and 10- 5mol / L A779 + 10 nmol / L cerulein). The control group was AR42 J cells with normal growth. The AR42 J cells in the model group were stimulated with 10 nmol / L cerulein and the cells were collected at 15 minutes,30 minutes,2 hours,6 hours,12 hours,and 24 hours after stimulation. The AR42 J cells in the Ang( 1- 7) group were treated with various concentrations of Ang( 1- 7) for30 minutes and then stimulated with cerulein for 12 hours,and then the cells were collected. The AR42 J cells in the A779 group were treated with various concentrations of A779 for 30 minutes and then stimulated with cerulein for 12 hours,and then the cells were collected. Immunofluorescence assay was used to determine the expression sites of TLR4 and NF- κB in AR42 J cells,and Western blot was used to measure the protein expression of TLR4 and NF- κB in AR42 J cells in each group. A one- way analysis of variance was used for comparison of continuous data between groups,and the least significant difference method was used for further comparison between any two groups. Results Both TLR4 and NF- κB were expressed in the cytoplasm of AR42 J cells. Compared with the control group,the model group showed significant increases in the expression of TLR4 at 30 minutes,2 hours,and 6 hours after modeling and a significant reduction at 12 hours after modeling( all P < 0. 05),as well as significant increases in the expression of NF- κB at 30 minutes,2 hours,6 hours,12 hours,and 24 hours after modeling( all P < 0. 05). The 10- 5mol / L Ang( 1- 7) group had significantly downregulated protein expression of TLR4 and NF- κB compared with the model group( 0. 570 ± 0. 046 vs 0. 893 ± 0. 057,0. 520 ± 0. 071 vs 0. 750 ± 0. 057,both P < 0. 05).The 10- 5mol / L A779 group had significantly upregulated protein expression of TLR4 and NF- κB compared with the model group( 0. 680± 0. 045 vs 0. 563 ± 0. 088,0. 617 ± 0. 071 vs 0. 453 ± 0. 054,both P < 0. 05). Conclusion In cerulein- stimulated AR42 J cells,Ang( 1- 7) can downregulate TLR4 and inhibit NF- κB activation.