Metaloproteinases de matriz derivadas de neutrófilos amplificam a lesão hepática induzida por drogas

Abstract

The liver plays pivotal role in biosynthetic, metabolic and detoxifying functions. Despite its known capacity for regeneration, in some conditions like excess medication, it can be damaged, compromising their function and the individual healthy. Drug-induced liver injury (DILI) has been more frequent in the world due to the easy access to drugs by the population. Among the several marketed drugs, acetaminophen (APAP) is being used indiscriminately, and the APAP overdose is the leading cause of acute liver failure (ALF). The sterile injury caused by APAP leads to inflammatory process with recruitment of many leukocytes to the liver, but in cases of acute inflammation, such as the liver necrosis, neutrophils are the first to be recruited and migrate in large numbers. These cells eventually amplify the liver damage and little is known about the effector mechanism of this amplification. Considering this, our objective was to identify the granular components present in neutrophils responsible for amplification of liver injury after APAP overdose. We started working using degranulation inhibitors and a reduction of the liver damage with the use of doxycycline and cromoglycate at doses of 50 and 100 mg/kg, and an increase in liver function with the highest dose of cromoglycate was observed. Among the components present in the granules, we first inhibit unspecific proteases with a cocktail and observed decreased liver damage and decreased number of neutrophils at the dose of 1.4 mg/mouse. After that, we tried to identify which proteases were being responsible for the results found. To this end, we inhibited each protease separately and found that the inhibition of MMPs with 2 mg/kg of MMP1 inhibitor was able to reduce the damage and improve liver function in addition to 40% reduction in MPO activity. To understand whether the reduction of the injury was due to the reduction of neutrophils, we inhibited neutrophils recruitment, with DF2156A inhibitor, and noted that even with the decrease in the number of neutrophils injury has not changed. We also inhibited ROS production in many pathways and there was no change in the injury and liver function. This way, we concluded that MMPs are responsible for increase hepatocyte death and decrease the hepatic functionality after APAP overdose.