Effect of activated CREBH protein on the expression of C-reactive protein in fatty-acid-induced steatotic hepatic cells

Objective To establish a steatosis hepatocyte model in vitro and explore the effect of activated cAMP-responsive element-binding protein H(CREBH) protein on the expression of C-reactive protein(CRP) in this model.Methods L02 cells were cultured with free fatty-acid (FFA) mixtures at different ratios of oleic acid and palmitic acid(2 ∶ 1,1 ∶ 2,and 0 ∶ 3) for 12 or 24 h to induce fat-overloading.Cell viability was investigated by CCK-8,the levels of CRP,CREBH,C/EBP homologous protein (CHOP),and immunoglobulin-binding protein (BIP) were detected by real-time PCR.The level of CREBH in nuclei was detected by western blot.Then CREBH siRNA or negative control siRNA was transfected into L02 cells,and cultured with FFA mixtures for 24 hours.The levels of CRP,CREBH,CHOP,and BIP were detected by real-time PCR.Results (1) Cells cultured with FFA mixtures showed significantly increased fat droplets compared with control group.The level of CRP was increased by FFA mixtures,depending on the proportion of palmitic acid.(2) The expression levels of CREBH were increased by FFA mixture(P＜0.05) and its expression in nuclear was also increased by FFA mixture.(3) Endoplasmic reticulum stress could be induced by FFA mixture,depending on the proportion of palmitic acid.(4)The CREBH siRNA could effectively reduce the expression level of CREBH mRNA.Compared with the negative control group,the expression levels of CRP mRNA were significantly decreased (P＜0.05).Conclusion Palmitic acid,but not oleic acid,could up-regulate the expression of CRP.Palmitic acid-induced expression of CRP was regulated by activated CREBH. Key words: Non-alcoholic fatty liver disease ;  CREBH ;  C-reactive protein ;  Endoplasmic reticulum stress ; Saturated fatty-acid