Tert‐butylhydroquinone attenuates LPS‐induced pyroptosis of IPEC‐J2 cells via downregulating HMGB1/TLR4/NF‐κB axis

Abstract Inflammatory response induced by biological stress usually occurs in weaning piglets, it reduces the production performance of piglets and even causes death. Tert‐butylhydroquinone (TBHQ) is a food additive that has the effect of anti‐inflammation and anti‐oxidation. However, there are few reports related to the protective mechanisms of TBHQ on lipopolysaccharide (LPS) induced injury in intestinal porcine epithelial (IPEC‐J2) cells. Quantitative real‐time polymerase chain reaction and western blot analysis, respectively, detected the mRNA levels and protein expressions related to pyroptosis, tight junction (TJ) protein and high‐mobility group box 1/toll‐like receptor 4/nuclear factor kappa‐B (HMGB1/TLR4/NF‐κB) axis. Localisation and expression of NOD‐like receptor pyrin domain containing 3 (NLRP3), HMGB1 and P‐NF‐κB proteins detected by immunofluorescence. The results showed that TBHQ (12.5 and 25 μM) can increase cell activity and reduce intracellular lactate dehydrogenase (LDH) levels in a dose‐dependent manner. LPS significantly decreases cell viability and increases the LDH level. However, pretreatment with TBHQ evidently increases cell viability and decreases the LDH level of IPEC‐J2 cells. In addition, treatment with LPS decreased the mRNA level and protein expression of zonula occludens‐1, occludin and claudin‐1, and increased the mRNA level and protein expression of pyroptosis and HMGB1/TLR4/NF‐κB axis. Interestingly, pretreatment with TBHQ increased the TJ protein expressions as well as decreased the mRNA level and protein expressions of pyroptosis and HMGB1/TLR4/NF‐κB axis. Moreover, the results of immunofluorescence showed that TBHQ significantly reduced the expression of NLRP3, HMGB1 and P‐NF‐κB in LPS‐induced injury of IPEC‐J2 cells. Therefore, we come to the conclusion that TBHQ attenuates LPS‐induced pyroptosis in IPEC‐J2 cells through downregulation of the HMGB1/TLR4/NF‐κB axis, TBHQ may become a potential feed additive for preventing inflammatory diarrhoea in piglets.