Dehydroepiandrosterone ameliorates hepatocellular damage in obstructive jaundice

Lower levels of dehydroepiandrosterone sulfate are associated with more advanced liver fibrosis in chronic hepatitis C

Chronic infection with the hepatitis C virus induces liver fibrosis, but it is unknown why some patients progress to advanced fibrosis while others remain with mild disease. Recently, an inverse association between serum levels of dehydroepiandrosterone sulphate (DHEA-S) and liver fibrosis in patients with nonalcoholic fatty liver disease was described, and it was postulated that dehydroepiandrosterone (DHEA) has antifibrotic effects. Our aim was to compare serum DHEA-S levels with liver fibrosis in hepatitis C patients. We collected serum samples from hepatitis C patients at the same day they underwent a liver biopsy. S-DHEA was compared to different stages of fibrosis. Binary logistic regression models were applied to evaluate independent variables associated to fibrosis. We included 287 patients (43.9% male). According to fibrosis stages 0, 1, 2, 3 and 4, median serum DHEA-S levels were 103 (26-462), 73 (5-391), 46 (4-425), 35 (6-292) and 28 (2-115) μg/dL, respectively (P < .001). Median serum DHEA-S levels were 74 (5-462) vs 36 (2-425) μg/dL for mild (F0-1) vs significant (F2-4) fibrosis, respectively (P < .001). Median serum DHEA-S levels were 64 (4-462) vs 31 (2-292) μg/dL for non advanced (F0-2) vs advanced fibrosis (F3-4), respectively (P < .001). The same association was found when the subgroup of HCV patients with and without steatosis or steatohepatitis was analysed. The association between lower DHEA-S levels and advanced fibrosis was independent of age, gender, diabetes mellitus, obesity and steatosis. Lower circulating DHEA-S levels are associated with more advanced stages of liver fibrosis in hepatitis C patients.

Inflammation-associated upregulation of the sulfated steroid transporter Slc10a6 in mouse liver and macrophage cell lines

AIM

Slc10a6, an incompletely characterized member of the SLC10A bile acid transporter family, was one of the most highly induced RNA transcripts identified in a screen for inflammation-responsive genes in mouse liver. This study aimed to elucidate a role for Slc10a6 in hepatic inflammation.

METHODS

Mice were treated with lipopolysaccharide (LPS; 2 mg/kg) or interleukin (IL)-1β (5 mg/kg) for various time points. Cells were treated with LPS (1 μg/mL) at various time points, with cell signaling inhibitors, nuclear receptor ligands and Slc10a6 substrates. All mRNA levels were determined by quantitative polymerase chain reaction.

RESULTS

Slc10a6 mRNA levels were upregulated in mouse liver at 2 h (7-fold), 4 h (100-fold) and 16 h (50-fold) after LPS treatment, and 35-fold by the cytokine IL-1β (4 h). Both absence of the nuclear receptor Fxr and pretreating mice with the synthetic retinoid X receptor-α ligand LG268 attenuated the LPS upregulation of Slc10a6 mRNA by 60-75%. In vitro, Slc10a6 mRNA was induced 30-fold by LPS in mouse RAW264.7 macrophages in a time-dependent manner (maximum at 8 h). The Slc10a6 substrate dehydroepiandrosterone sulfate (DHEAS) enhanced LPS induction of CCL5 mRNA, a pro-inflammatory chemokine, by 50% in RAW264.7 cells. This effect was abrogated in the presence of anti-inflammatory nuclear receptor ligands 9-cis-retinoic acid and dexamethasone.

CONCLUSION

Dramatic upregulation of Slc10a6 mRNA by LPS combined with enhanced LPS stimulation of CCL5 expression by the Slc10a6 substrate DHEAS in macrophages suggests that Slc10a6 function contributes to the hepatic inflammatory response.

Interleukin-10 suppresses hepatic TGF-β1 expression and attenuates hepatocyte apoptosis in biliary-obstructed rats

AIM: To explore the effect of interleukin-10 (IL-10) on hepatocyte apoptosis in biliary-obstructed rats.

METHODS: Male Wistar rats were divided randomly into sham operation (SO) group, obstructive jaundice (OJ) group and IL-10 group. Rats of the OJ and IL-10 groups underwent ligation and severing of the common bile duct, while mobilization of the common bile duct was performed in the SO group. The IL-10 group was intraperitoneally injected with IL-10 (4 μg/kg) daily after operation. The mRNA and protein expression of transforming growth factor-β1 (TGF-β1) in liver tissue was detected by fluorescence real-time quantitative PCR and immunohistochemical staining, respectively. Blood samples were taken to measure serum total bilirubin (TBIL), direct bilirubin (DBIL), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels, while hepatic cell apoptosis was evaluated by TUNEL method.

RESULTS: Compared to the SO group, the levels of serum ALT and AST, hepatic TGF-β1 mRNA and protein expression, and hepatic cell apoptosis index significantly increased in the OJ group 3 days after operation (ALT: 91.83 U/L ± 21.47 U/L vs 47.67 U/L ± 12.79 U/L; AST: 208.67 U/L ± 32.36 U/L vs 75.17 U/L ± 11.96 U/L; TGF-β1 mRNA: 7.48 ± 1.51 vs 1.21 ± 0.79; TGF-β1 protein: 6.11% ± 1.11% vs 1.26% ± 0.64%; apoptosis: 15.06% ± 1.17% vs 3.94% ± 0.46%; all P < 0.05), and further increased 7 d after operation (ALT: 178.83 U/L ± 46.25 U/L vs 44.50 U/L ± 9.97 U/L; AST: 461.17 U/L ± 88.48 U/L vs 76.50 U/L ± 12.39 U/L; TGF-β1 mRNA: 11.98 ± 3.05 vs 1.01 ± 0.52; TGF-β1 protein: 9.97% ± 2.84% vs 1.68% ± 0.71%; apoptosis: 23.49% ± 3.35% vs 4.31% ± 0.67%; all P < 0.05). Treatment with IL-10 significantly decreased hepatic function, hepatic TGF-β1 expression, and hepatic cell apoptosis compared to the OJ group 7 d after operation (ALT: 94.17 U/L ± 20.02 U/L vs 178.83 U/L ± 46.25 U/L; AST: 257.83 U/L ± 56.53 U/L vs 461.17 U/L ± 88.48 U/L; TGF-β1 mRNA: 7.05 ± 1.15 vs 11.98 ± 3.05; TGF-β1 protein: 7.06% ± 1.32% vs 9.97% ± 2.84%; apoptosis: 15.08% ± 1.69% vs 23.49% ± 3.35%; all P < 0.05).

CONCLUSION: IL-10 could attenuate hepatocyte apoptosis by suppressing hepatic TGF-β1 expression in biliary-obstructed rats.