MicroRNA-223 ameliorates alcoholic liver injury by inhibiting the IL-6–p47^phox–oxidative stress pathway in neutrophils

Abstract

ObjectivesChronic-plus-binge ethanol feeding activates neutrophils and exacerbates liver injury in mice. This study investigates how recent excessive drinking affects peripheral neutrophils and liver injury in alcoholics, and how miR-223, one of the most abundant microRNAs (miRNAs) in neutrophils, modulates neutrophil function and liver injury in ethanol-fed mice.DesignsThree hundred alcoholics with (n=140) or without (n=160) recent excessive drinking and 45 healthy controls were enrolled. Mice were fed an ethanol diet for 10 days followed by a single binge of ethanol.ResultsCompared with healthy controls or alcoholics without recent drinking, alcoholics with recent excessive drinking had higher levels of circulating neutrophils, which correlated with serum levels of alanine transaminase (ALT) and aspartate transaminase (AST). miRNA array analysis revealed that alcoholics had elevated serum miR-223 levels compared with healthy controls. In chronic-plus-binge ethanol feeding mouse model, the levels of miR-223 were increased in both serum and neutrophils. Genetic deletion of the miR-223 gene exacerbated ethanol-induced hepatic injury, neutrophil infiltration, reactive oxygen species (ROS) and upregulated hepatic expression of interleukin (IL)-6 and phagocytic oxidase (phox) p47phox. Mechanistic studies revealed that miR-223 directly inhibited IL-6 expression and subsequently inhibited p47phox expression in neutrophils. Deletion of the p47phox gene ameliorated ethanol-induced liver injury and ROS production by neutrophils. Finally, miR-223 expression was downregulated, while IL-6 and p47phox expression were upregulated in peripheral blood neutrophils from alcoholics compared with healthy controls.ConclusionsmiR-223 is an important regulator to block neutrophil infiltration in alcoholic liver disease and could be a novel therapeutic target for the treatment of this malady.

Alcohol, Diet and Drug Use Preceding Alcoholic Hepatitis

“…This is comparable with our finding of a baseline alcohol intake of around 20 UK units of alcohol. A recent study of patients admitted for alcohol detoxification found higher neutrophil counts among those who had been drinking up to the point of admission compared to those who had stopped at least 10 days before admission [15]. In our cohort, we saw a similar effect in the patients who had increased their alcohol intake.…”

Mitochondrial DNA–enriched microparticles promote acute-on-chronic alcoholic neutrophilia and hepatotoxicity

“…Our recent human data showed that EAU + RD patients had much higher levels of circulating neutrophils, which positively correlated with elevated serum levels of ALT and AST (5). To further explore the underlying mechanism of neutrophilia, particularly in those with recent excessive alcohol drinking, we analyzed serum EVs, MPs, and mtDNA content in 171 EAU patients in whom serum samples were available.…”

“…The above human data suggest that recent excessive alcohol (binge) drinking leads to the elevation in the levels of serum mtDNA and circulating neutrophils. To explore the underlying mechanisms, we used a E10d + 1B ethanol feeding mouse model, which mimics the EAU + RD pattern in humans (5). As illustrated in Figure 2A, the number and percentage of circulating neutrophils were also elevated in the E10d + 1B group The total numbers of particles in the sera of healthy control human (control, n = 30), EAU -RD (n = 71), and EAU + RD (n = 100) patients were counted using an NTA system.…”

“…The recruitment strategy of the human subject cohort was reported in our previous study (5). In brief, healthy controls were recruited from the clinics at the Roudebush Veterans Administration Medical Center, and patients with chronic EAU were from Fairbanks Drug and Alcohol Treatment Center (Indianapolis, Indiana, USA).…”

“…However, the mechanisms underlying hepatic neutrophil infiltration in alcoholics are not fully understood. Recently, we reported that chronic excessive alcohol use (EAU) patients with recent excessive drinking (RD) (EAU + RD) had much higher levels of circulating neutrophils, which positively correlated with elevated serum levels of alanine transaminase (ALT) and aspartate transaminases (AST) when compared with those without RD (EAU -RD) and healthy controls (5). These clinical data suggest that RD (or binge drinking) in patients with chronic EAU elevates peripheral blood neutrophils and likely leads to hepatic neutrophil infiltration and liver injury.…”