Fig. 5: C/EBPβ mediates the upregulation of LCN2 by SIRT2 under ethanol stress.

a Venn diagram shows common transcription factors predicted as the putative shared regulators on LCN2, Hp, Saa3, Saa1, Hpx, and Orm2. b Western blot analysis of hepatic LCN2, C/EBPβ, and SIRT2 expression in pair and EtOH-fed mice. c, d LCN2 mRNA expression after C/EBPβ knockdown (KD) or overexpression (C/EBPβ) in AML12 cells by qRT-PCR analysis. ^#P < 0.05 and ^###P < 0.001 are used to indicate statistical significance compared between the group with EtOH treatment and the corresponding group without EtOH treatment. e Dual-luciferase reporter assay was performed in HK293T cells. Western blot analysis of C/EBPβ expression (top) and luciferase activities of the LCN2 promoter-reporter system (bottom) are shown. f UCSC Epigenome Browser tracks of the C/EBPβ ChIP-seq signal −3 kb before TSS of LCN2 from Cistrome DB ToolKit (top); information about predicted C/EBPβ binding sites and the primers targeting different sites on LCN2 promoter (middle); ChIP analysis showing C/EBPβ occupancy at the LCN2 proximal promoter in AML12 cells treated with EtOH and control (bottom). PPARγ and distant region primers were, respectively, used as a positive and negative control. g qRT-PCR analysis of LCN2 mRNA expression in SIRT2 knockdown AML12 cells transfected with C/EBPβ. Student’s t-test was used for statistical evaluation. Data are shown as means ± SD and are considered statistically significant at *P < 0.05, **P < 0.01, and ***P < 0.001.