Current and emerging biomarkers of hepatotoxicity

Xi Yang, William F Salminen, Laura K SchnackenbergDivision of Systems Biology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR, USAAbstract: Drug-induced liver injury (DILI) is of great concern to human health. Generally, liver function and injury is evaluated based upon clinical signs, a select group of serum clinical biomarkers, and occasionally liver biopsies. While alanine aminotransferase, the most commonly used biomarker of hepatocellular injury, is a sensitive marker of liver injury, it is not necessarily specific for liver injury. Furthermore, alanine aminotransferase levels may not always correlate with the extent of injury. Therefore, new hepatotoxicity biomarkers are needed that are more predictive and specific indicators of liver injury and altered function. In addition, no current biomarker provides prognostic information about ultimate outcome once injury occurs, and any new biomarker filling this need is desperately needed. The omics technologies, including genomics, proteomics, and metabolomics, are being used in preclinical animal studies as well as clinical studies to evaluate markers of hepatotoxicity in easily obtained biofluids, such as urine and serum. Recently, the evaluation of circulating microRNAs in urine and blood has also shown promise for the identification of novel, sensitive markers of liver injury. This review evaluates the current status of proposed biomarkers of hepatotoxicity from the omics platforms, as well as from analysis of microRNAs. A brief description of the qualification of proposed biomarkers is also given.Keywords: biomarkers, hepatotoxicity, metabolomics, microRNA, proteomics, transcriptomics