Integrated analysis of mRNA and miRNA expression in response to interleukin-6 in hepatocytes

• Analysis of miRNA and mRNA transcriptomes in hepatocyte acute phase response
• Investigated mRNA and miRNA expression between cell types after IL-6 stimulation
• Certain miRNAs regulate important acute phase response genes.
• Changes in gene and miRNA expression can be cell-type and time point-specific.

The expression of plasma proteins changes dramatically as a result of cytokine induction, particularly interleukin-6, and their levels are used as clinical markers of inflammation. miRNAs are important regulators of gene expression and play significant roles in many inflammatory diseases and processes. The interactions between miRNAs and the genes that they regulate during the acute phase response have not been investigated. We examined the effects of IL-6 stimulation on the transcriptome and miRNome of human and mouse primary hepatocytes and the HepG2 cell line. Using an integrated analysis, we identified differentially expressed miRNAs whose seed sequences are significantly enriched in the 3′ untranslated regions of differentially expressed genes, many of which are involved in inflammation-related pathways. Our finding that certain miRNAs may de-repress critical acute phase proteins within acute timeframes has important biological and clinical implications.