Thioredoxin-1 Increases Survival in Sepsis by Inflammatory Response Through Suppressing Endoplasmic Reticulum Stress

Sepsis is the main cause of death in critically ill patients, pathogenesis of which is still unclear. The nuclear factor κB (NF-κB) inflammatory signal pathway mediated by endoplasmic reticulum stress is involved in sepsis. Thioredoxin-1 (Trx-1) is an important protein of regulating oxidative stress. It plays a crucial role in the anti-oxidation, anti-apoptosis, and anti-inflammation. However, the role and the mechanism of Trx-1 in sepsis have not been extensively studied. In the present study, we showed that the survival was longer in sepsis induced by cecal ligation and puncture in Trx-1 overexpression transgenic (Tg) mice compared with wild-type mice. Wet/dry lung weight ratio was decreased in Trx-1 Tg mice. The levels of TNF-α and IL-1β in plasma and lung tissue were inhibited in Tg mice. The expressions of glucose-regulated protein 78, inositol-requiring enzyme 1α (IRE1α), tumor necrosis factor receptor-associated factor 2, C/EBP homologous protein, NF-κB, and inhibitors of NF-κBα were increased in lung tissue. More importantly, the overexpression of Trx-1 in transgenic mice suppressed NF-κB inflammatory signal pathway by inhibiting the activation of molecules involved in ER stress. Our results suggest that Trx-1 may play protective role in extending survival in sepsis by regulating inflammatory response through suppressing ER stress.