Liver Immune Cells Release Type 1 Interferon Due to DNA Sensing and Amplify Liver Injury from Acetaminophen Overdose

Abstract

Hepatocytes may rupture after a drug overdose, and their intracellular contents act as damage-associated molecular patterns (DAMPs) that lead to additional leukocyte infiltration, amplifying the original injury. Necrosis-derived DNA can be recognized as a DAMP, activating liver non-parenchymal cells (NPCs). We hypothesized that NPCs react to DNA by releasing interferon (IFN)-1, which amplifies acetaminophen (APAP)-triggered liver necrosis. We orally overdosed different knockout mouse strains to investigate the pathways involved in DNA-mediated amplification of APAP-induced necrosis. Mice were imaged under intravital confocal microscopy to estimate injury progression, and hepatocytes and liver NPCs were differentially isolated for gene expression assays. Flow cytometry (FACS) using a fluorescent reporter mouse estimated the interferon-beta production by liver leukocytes under different injury conditions. We also treated mice with DNase to investigate the role of necrosis DNA signaling in IFN-1 production. Hepatocytes released a large amount of DNA after APAP overdose, which was not primarily sensed by these cells. However, liver NPCs promptly sensed such environmental disturbances and activated several DNA sensing pathways. Liver NPCs synthesized and released IFN-1, which was associated with concomitant hepatocyte necrosis. Ablation of IFN-1 recognition in interferon α/β receptor (IFNAR−/−) mice delayed APAP-mediated liver necrosis and dampened IFN-1 sensing pathways. We demonstrated a novel loop involving DNA recognition by hepatic NPCs and additional IFN-1 mediated hepatocyte death.

Prolonged neutrophil survival at necrotic sites is a fundamental feature for tissue recovery and resolution of hepatic inflammation

“…Mice were fasted for 12–15 h before a single administration of APAP (600 mg/kg) or vehicle as previously described 20 . Fasting was performed to assure full APAP absorption and reproducibility among experiments.…”

“…Mice were fasted for 12-15 h before a single administration of APAP (600 mg/kg) or vehicle as previously described. 20 Fasting was performed to assure full APAP absorption and reproducibility among experiments. APAP (Sigma-Aldrich, St. Louis, MO, USA) was diluted in warm saline 0.9% at a concentration of 75 mg/mL prior oral gavage.…”

A Potential Role for Mitochondrial DNA in the Activation of Oxidative Stress and Inflammation in Liver Disease

“…NLRP3 deletion and the related inflammatory body components ASC and caspase-1 could prevent the induction of liver failure [ 66 ]. In addition, mtDNA also activate the GAS-STING pathway to accelerate APAP-induced liver injury, and ablation of IFN I recognition in interferon α / β receptor (IFNAR−/−) mice protected them from APAP-induced liver injury by limiting the GAS-STING pathway [ 68 ]. Chlorpromazine is an antischizophrenia dopamine inhibitor that activates autophagy to remove damaged mitochondria and protect mice from APAP-induced liver damage [ 69 ].…”

Danger-Associated Molecular Patterns (DAMPs): Molecular Triggers for Sterile Inflammation in the Liver

“…In mouse models of APAP intoxication, mtDAMPs have been shown to contribute to neutrophil-mediated injury as blocking the receptors for NFPs (i.e., FPR1) and for mtDNA (TLR9) reduced liver injury [ 109 ]. Another group confirmed the release of large amounts of DNA after APAP overdose, its deposition within the liver microvasculature and its lining along the sinusoidal lumen [ 101 ]. Furthermore, the authors demonstrated sensing of DNA via cGAS and STING, as mice deficient in cGAS or STING were completely resistant to APAP-induced liver injury.…”

“…Furthermore, the authors demonstrated sensing of DNA via cGAS and STING, as mice deficient in cGAS or STING were completely resistant to APAP-induced liver injury. Moreover, by employing IFNAR-deficient mice and in vitro analyses on hepatocytes and non-parenchymal cells they provided evidence for a role of non-parenchymal type I IFNs in amplification of liver injury [ 101 ].…”