New microRNA Biomarkers for Drug-Induced Steatosis and Their Potential to Predict the Contribution of Drugs to Non-alcoholic Fatty Liver Disease

Abstract

Background and Aims: Drug-induced steatosis is a major reason for drug failure in clinical trials and post-marketing withdrawal; and therefore, predictive biomarkers are essential. These could be particularly relevant in non-alcoholic fatty liver disease (NAFLD), where most patients show features of the metabolic syndrome and are prescribed with combined chronic therapies, which can contribute to fatty liver. However, specific biomarkers to assess the contribution of drugs to NAFLD are lacking. We aimed to find microRNAs (miRNAs) responsive to steatotic drugs and to investigate if they could become circulating biomarkers for drug-induced steatosis.Methods: Human HepG2 cells were treated with drugs and changes in miRNA levels were measured by microarray and qRT-PCR. Drug-induced fat accumulation in HepG2 was analyzed by high-content screening and enzymatic methods. miRNA biomarkers were also analyzed in the sera of 44 biopsy-proven NAFLD patients and in 10 controls.Results: We found a set of 10 miRNAs [miR-22-5p, -3929, -24-2-5p, -663a, -29a-3p, -21 (5p and 3p), -27a-5p, -1260 and -202-3p] that were induced in human HepG2 cells and secreted to the culture medium upon incubation with model steatotic drugs (valproate, doxycycline, cyclosporin A and tamoxifen). Moreover, cell exposure to 17 common drugs for NAFLD patients showed that some of them (e.g., irbesartan, fenofibrate, and omeprazole) also induced these miRNAs and increased intracellular triglycerides, particularly in combinations. Finally, we found that most of these miRNAs (60%) were detected in human serum, and that NAFLD patients under fibrates showed both induction of these miRNAs and a more severe steatosis grade.Conclusion: Steatotic drugs induce a common set of hepatic miRNAs that could be used in drug screening during preclinical development. Moreover, most of these miRNAs are serum circulating biomarkers that could become useful in the diagnosis of iatrogenic steatosis.

Interplay of lamin A and lamin B LADs on the radial positioning of chromatin

“…Our findings, rather, are reminiscent of partial pre-lamin A processing observed after depletion or inhibition of isoprenylcysteine carboxymethylation [24]. We cannot at present exclude that this pre-lamin A accumulation results from a senescence phenotype or cellular stress elicited by CsA [1,2,23,25]. Accumulation of pre-lamin A at the nuclear envelope however suggests that interactions of chromatin with the nuclear lamina could be altered.…”

“…Drug-induced hepatotoxicity, a common cause of clinical trial failure, has led to the use of cellular models such as HepG2 hepatocarcinoma cells for drug testing [1,2]. At micromolar concentrations, the steatotic drug cyclosporin A (CsA) inhibits several signaling pathways in HepG2 cells [3], resulting in metabolic alterations [1,3,4].…”

Adipose may actively delay progression of NAFLD by releasing tumor‐suppressing, anti‐fibrotic miR‐122 into circulation

“…The NAFLD‐associated changes in the spectrum of extracellular miRNA species present in human blood have been the subject of more than one intensive investigation . Each of these reports showed that circulating miRNAs reflect liver damage more precisely than do serum transaminases.…”

“…According to a very thorough RNA-Seq-based study by Hou et al, miR-122 is expressed almost exclusively in the liver, comprising more than 52% of the total pool of liver miRNAs (66). Overwhelming majority of published reports agree that the levels of miR-122 in sera of NAFLD individuals are elevated (53)(54)(55)(56)(57)(59)(60)(61)(62). If a majority of miRNAs present in circulation of individuals with NAFLD originate from the liver, it would be reasonable to expect an increase in the expression of miR-122 in hepatic parenchyma, along with a progression of NAFLD across its stages.…”

“…The NAFLD-associated changes in the spectrum of extracellular miRNA species present in human blood have been the subject of more than one intensive investigation (50,(53)(54)(55)(56)(57)(58)(59)(60)(61)(62)(63). Each of these reports showed that circulating miRNAs Tissue-cooperative homeostatic model of NAFLD A.…”