Abundance of Cytochromes in Hepatic Extracellular Vesicles Is Altered by Drugs Related With Drug‐Induced Liver Injury

Abstract

Drug‐induced liver injury (DILI) is a serious worldwide health problem that accounts for more than 50% of acute liver failure. There is a great interest in clinical diagnosis and pharmaceutical industry to elucidate underlying molecular mechanisms and find noninvasive biomarkers for this pathology. Cell‐secreted extracellular vesicles (EVs) have provided a new biological source to identify low disease invasive markers. Despite the intense research developed on these vesicles, there is currently a gap on their patho‐physiological effects. Here, we study EVs secreted by primary rat hepatocytes challenged with galactatosamine (GalN), acetaminophen, or diclofenac as DILI in vitromodels. Proteomics analysis of these EVs revealed an increase in enzymes already associated with liver damage, such as catecholamine‐methyl transferase and arginase 1. An increase in translation‐related proteins and a decrease in regulators of apoptosis were also observed. In addition, we show the presence of enzymatic activity of P450 cytochrome 2d1 in EVs. The activity specifically is decreased in EVs secreted by hepatocytes after acetaminophen treatment and increased in EVs derived from GalN‐treated hepatocytes. By using in vivo preclinical models, we demonstrate the presence of this cytochrome activity in circulation under normal conditions and an increased activity after GalN‐induced injury. Conclusion: Hepatocyte‐secreted EVs carry active xenobiotic‐metabolizing enzymes that might be relevant in extracellular metabolism of drugs and be associated with DILI. (Hepatology Communications 2018;0:00‐00)

Circulating Extracellular Vesicles Containing Xenobiotic Metabolizing CYP Enzymes and Their Potential Roles in Extrahepatic Cells Via Cell–Cell Interactions

“…Furthermore, studies have revealed that EVs carry a multitude of drug metabolizing enzymes, including members of the CYP enzyme group [23,83,84] (Table 2). However, the presence and amount of CYP enzymes is likely to vary greatly depending on the EV source, whether the EVs are isolated from plasma or a specific cell line, as well as the physiological condition of the cells from which they originate [85].…”

“…For example, alcohol use increases CYP2E1 expression in plasma EVs [88] and there is a correlation between increased CYP2E1 level and alcohol-induced liver injury [99]. Furthermore, alcohol exposure increases EV release into the circulation [88], making circulatory EVs a potential source of biomarkers in the setting of drug-induced liver injury [84,100].…”

Metabolic Nano-Machines: Extracellular Vesicles Containing Active Enzymes and Their Contribution to Liver Diseases

“…The presence of cytochromes in rat hepatocytederived EVs was described in vitro [31], but also in vivo, where increasing values of active Cyp2d1 was observed in rats under DILI challenge [55], and interestingly, it has been described that there is an increasing activity of CYP2E1 in circulating EVs isolated from human samples after alcohol exposure [56]. Potentially, circulating active cytochromes could trigger activation of drugs, such as acetaminophen, which could end up in tissue damage, in the same way that liver-produced toxic metabolites are toxic for other tissues [91].…”

From Endogenous Compounds as Biomarkers to Plasma‐Derived Nanovesicles as Liquid Biopsy; Has the Golden Age of Translational Pharmacokinetics‐Absorption, Distribution, Metabolism, Excretion‐Drug–Drug Interaction Science Finally Arrived?

“…Undoubtedly, the successful implementation of Genotyping, Exosome, M&S, and Biomarker (“GEMB”)‐based methods, by minimizing probe drug administration and obviating the need for invasive tissue biopsy, would be a great boon to nonclinical researchers and clinical pharmacologists. Further expansion of GEMB–based approaches with other aspects of clinical testing, such as TOX and pharmacodynamics, could also advance translational PK‐pharmacodynamics‐ADME‐DDI‐TOX science in the service of patients, researchers, and agency reviewers …”