Identification of key genes, MicroRNAs and potentially regulated pathways in alcoholic hepatitis by integrative analysis.

Alcoholic hepatitis (AH) is a severe form of alcoholic liver disease associated with high mortality. Current pharmacological treatment options are not fully effective, and novel target therapies are urgently needed. Until now, key genes, miRNAs and potential signaling pathways in AH remain unclear. Here, we integrated mRNA and miRNA expression profiles to reveal 1411 differentially expressed genes (DEG) and 69 differentially expressed miRNAs (DEM) in AH. And then 51 overlapping genes were identified by compared with miRNA target genes and DEGs, which named as consistent expression genes (CEGs). Pathway analysis showed that CEGs were mainly enriched in PI3K-Akt signaling pathway, MicroRNAs in cancer, FoxO signaling pathway, TNF signaling pathway and P53 signaling pathway. A total of 8 hub genes，FOS, FOXO1, SIRT1, ESR1, BCL2L11, CDK1, CCNB1 and CDKN1A, were screened using protein-protein interaction network analysis. In the regulatory network of miRNA and hub genes, a total of five miRNAs, miR-29c, miR-92b, miR-132, miR-221, miR-222, were identified as key miRNAs. Among them, miR-132 has been shown to target SIRT1, FOXO1, CDKN1A and BCL2L11, and miR-92b targets SIRT1 and BCL2L11. miR-221 and miR-222 both target FOS, ESR1, and BCL2L11. In addition, miR-29c is one of the major down-regulated miRNAs in AH, targeting FOS. Western blot analysis showed that SIRT1 and FoxO1 were expressed at low levels (P < 0.05) and CDK1 was highly expressed in the AH group (P < 0.05). The other five proteins were not significantly different between the two groups (P > 0.05). RT-PCR results showed that miR-132 was significantly higher in the AH group than in the normal group (P < 0.05), while miR-29c was lower than the normal group (P < 0.05), and the other three miRNAs were not significantly different between the two groups (P > 0.05). Therefore, SIRT1, FOXO1, CDK1, miR-132 and miR-29c are involved in the regulation of FoxO and P53 signaling pathways, cell cycle and other biological processes, which may play a key role in the pathogenesis of AH.