Effects of TLR9/NF-κB on oxidative stress and inflammation in IPEC-J2 cells

Oxidative stress is one of the most important factors affecting large-scale breeding, especially the performance of pigs. Oxidative stress plays a role by affecting various genes in pigs, which can cause serious body damage, functional degradation and reduce production performance.

The purpose of this study was to investigate the effect of Toll like receptor 9 (TLR9) pathway on IPEC-J2 cells under oxidative stress and to provide reference for the growth development of Dapulian pigs.

In this study, Diquat was used as a source of oxidative stress to study the effects on Dapulian pigs by detecting relevant indicators. Then the IPEC-J2 cells were selected to verify the TLR9 signaling pathway in oxidative stress.

Compared with the control group, superoxide dismutase (SOD) in experimental group decreased significantly, malondialdehyde (MDA) was significantly increased, accompanied by inflammatory reaction, and inflammatory factors were significantly increased in the experimental group. Oxidative stress model was constructed by H2O2 incubating IPEC-J2 cells. The interference and overexpression vectors of TLR9 and myeloid differentiation primary response protein 88 (MyD88) were constructed to detect the activity of antioxidant enzymes and related proteins. The results showed that overexpression of TLR9 enhanced the activity of antioxidant enzymes, decreased the secretion of inflammatory factors, and decreased the activity of MDA，reactive oxygen species (ROS); the results were opposite after TLR9 interference. This study also showed that H₂O₂ can activate the nuclear factor-κB (NF-κB) pathway and promote the translocation of NF-κB into the nucleus. After co-transfection with TLR9 and MyD88, the results showed that TLR9 regulated the expression of NF-κB through MyD88.

The study showed that TLR9 pathway had a significant positive effect on antioxidant.