Effects of bilirubin on hepatic stellate cells in vitro

Objective To investigate the influence of low bilirubin level on hepatic stellate cells (HSCs) in vitro. Methods HSCs were isolated and cultured from the liver of SD rats. The effect of bilirubin in different concentration on reactive oxygen in HSCs was determined by DCFH-DA kit. The proliferation of HSCs was tested by CCK-8 test kit.Smoothmuscle α-actin (α-SMA) expression of HSCs was tested by Western blot.The apoptosis of HSCs was tested by flow cytometry.The fibrosis-related genes were tested by PCR. Results HSCs were isolated and cultured successfully.Bilirubin in low concentration (0,1,10,20 mg/L) inhibited the generation of the reactive oxygen.Proliferation and α-SMA expression of HSCs was inhibited by bilirubin (0.624 ± 0.092,0.536 ± 0.127,0.407 ± 0.033,0.399 ± 0.022,F =13.454,P ＜0.05 ; 339 ± 2,336 ± 10,246 ± 7,242 ± 5,3.7 ± 0.3,F =191.107,P ＜ 0.05 ) and the apoptosis of HSCs was promoted by bilirubin(2.69 ±0.07％,2.95 ±0.10％,4.41 ±0.22％,4.91 ±0.86％,F =34.731,P ＜0.05 ).Bilirubin in low concentration changed the expression of fibrosis-related genes in HSCs.The ratio of TIMP-1mRNA/MMP-2mRNA decreased (54 ± 2,65 ± 2,47 ± 2,44 ± 2,F =73.400,P ＜ 0.05).Conclusions Bilirubin in low concentration inhibits the proliferation and activation of hepatic stellate cells,orobablv bv a mechanism in which bilirubin promoted antioxidative function. Key words: Bilirubin; Liver cirrhosis; Hepatic stellate cells; Activation