Human liver biopsy of different phases from control to NASH

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder in industrialized countries. Liver samples from morbidly obese patients (N=45) with all stages of NAFLD and controls (N=18) were analysed by array-based DNA methylation and mRNA expression profiling. NAFLD-specific expression and methylation differences were seen for nine genes coding for key enzymes in intermediate metabolism (including PC, ACLY, PLCG1) and insulin/insulin-like signalling (including IGF1, IGFBP2, PRKCE) and replicated by bisulfite pyrosequening (independent N=39). Transcription factor binding sites at NAFLD-specific CpG sites were >1000-fold enriched for ZNF274, PGC1A and SREBP2. Intra-individual comparison of liver biopsies before and after bariatric surgery showed NAFLD-associated methylation changes to be partially reversible. Post-bariatric and NAFLD-specific methylation signatures were clearly distinct both in gene-ontology and transcription factor binding site analyses, with >400-fold enrichment of NRF1, HSF1 and ESRRA sites. Our findings provide one of the first examples of treatment-induced epigenetic organ remodelling in humans.

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Ahrens M, Ammerpohl O, von Schönfels W, Kolarova J, Bens S, Itzel T, Teufel A, Herrmann A, Brosch M, Hinrichsen H, Erhart W, Egberts J, Sipos B, Schreiber S, Häsler R, Stickel F, Becker T, Krawczak M, Röcken C, Siebert R, Schafmayer C, Hampe J