Itaconic acid facilitates inflammation abatement and alleviates liver ischemia-reperfusion injury by inhibiting NF-κB/NLRP3/caspase-1 inflammasome axis

Abstract

BACKGROUND: Ischemia-reperfusion injury (IRI) severely limits the efficacy and donor source of liver transplantation, and the crucial step in alleviating it is to control inflammation. Itaconic acid is a metabolite produced by intrinsic immune cells (especially macrophages) in the inflammatory state and can promote inflammation subsidence. However, its role in liver ischemia-reperfusion is insufficiently clarified. METHODS: A mouse liver ischemia-reperfusion model was constructed, and blood and liver tissue samples were collected by sequential euthanasia of mice at pre-set time points. Liver function and inflammatory factor concentrations were measured, and HE staining was conducted. In the hypoxia-reoxygenation model, proteins were collected at pre-set time points, and the expression of NF-κB pathway-associated protein and its downstream inflammation-associated protein NLRP3 and caspase-1 were detected by Western blot, immunohistochemistry, and immunofluorescence. The level of P-P65 in the nucleus was detected by immunofluorescence. RESULTS: In the liver ischemia-reperfusion model, liver function and inflammatory factors were dynamically varied with reperfusion time in mice, and itaconic acid significantly modified liver function and inflammatory status during this process. NF-κB pathway activity was dynamically varied during hypoxia-reoxygenation, and itaconic acid significantly inhibited the activity of the pathway and significantly suppressed the expression of its downstream inflammation-related proteins. CONCLUSIONS: Itaconic acid inhibits NF-κB pathway activation and reduces the accumulation of P-P65 in the nucleus. In turn, this reduces NLRP3 and caspase-1 expression of downstream inflammation-related proteins, promotes inflammation regression, and attenuates liver IRI.