U6 is unsuitable for normalization of serum miRNA levels in patients with sepsis or liver fibrosis

摘要: MicroRNA (miRNA) levels in serum have recently emerged as potential novel biomarkers for various diseases. miRNAs are routinely measured by standard quantitative real-time PCR (qPCR); however, the high sensitivity of qPCR demands appropriate normalization to correct nonbiological variation. Presently, RNU6B (U6) is used data circulating many studies. However, it was suggested that U6 themselves might differ between individuals. Therefore, no consensus has been reached on best strategy 'circulating miRNA'. We analyzed well spiked-in SV40-RNA sera 44 healthy volunteers, 203 intensive care unit patients and 64 with liver fibrosis. Levels demonstrated a variability donors, critical illness This could also be confirmed mice after cecal ligation puncture procedure. Most importantly, were significantly upregulated sepsis compared controls correlated established markers inflammation. In fibrosis, downregulated. contrast, SV40 displayed higher stability both human cohorts (healthy, illness, fibrosis) mice. Thus, we conclude dysregulated disease-specific manner. should not inflammatory diseases previous studies using this approach interpreted caution. Further warranted identify specific regulatory processes