Selenium supplementation attenuates procollagen-1 and interleukin-8 production in fat-loaded human C3A hepatoblastoma cells treated with TGFbeta1.
BACKGROUND
Non-alcoholic fatty liver disease (NAFLD) is associated with obesity, insulin resistance and hepatic steatosis. Non-alcoholic steatohepatitis (NASH) is a serious consequence of NAFLD where chronic tissue damage and inflammation result in fibrosis which may progress to cirrhosis. Transforming growth factor beta1 (TGFbeta1), proinflammatory cytokines and oxidative stress are thought to play crucial roles in the pathogenesis of these conditions. The contributions of individual liver cell types to fibrogenesis remain controversial and the influence of selenium status has not been investigated.


METHODS
In this study we have used a cell culture model of fat-loading using oleate-treated human hepatoblastoma (C3A) cells to investigate how fat-loading and selenium status might influence the production of collagen in response to TGFbeta1. The secretion of inflammatory cytokines was also investigated, together with the epithelial character of the treated cells.


RESULTS
We found that in response to treatment with TGFbeta1, C3A cells produced mRNA encoding the pro-alphaI chain of procollagen I, secreted procollagen I peptide, up-regulated production of the proinflammatory cytokine interleukin-8 (IL-8) and the mesenchymal marker vimentin, and down-regulated albumin production. Most of these responses were considerably enhanced when cells were fat-loaded with oleate and were attenuated by selenium addition at a dose that optimised the expression of thioredoxin reductase and glutathione peroxidase.


CONCLUSIONS
Our data establish that both fat-loading and suboptimal selenium status enhance collagen and IL-8 production by C3A hepatocytes in response to TGFbeta1, possibly as part of an epithelial to mesenchymal transition.


CONCLUSIONS
These findings suggest that the hepatocyte may be an important contributor to the pathogenesis of fibrosis associated with NAFLD.
Clarke
Catriona
C
Clinical Biochemistry, Western General Hospital, Edinburgh, UK. catriona.clarke@nhs.net
Baghdadi
Hussam
H
Howie
Alexander F
AF
Mason
J Ian
JI
Walker
Simon W
SW
Beckett
Geoffrey J
GJ
D001483:Base Sequence; D045744:Cell Line, Tumor; D017931:DNA Primers; D004847:Epithelial Cells / Q000166:cytology; D005223:Fats / Q000032:analysis*; D018197:Hepatoblastoma / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis*; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D008648:Mesoderm / Q000166:cytology; D016133:Polymerase Chain Reaction; D011347:Procollagen / Q000096:biosynthesis*; D012643:Selenium / Q000008:administration & dosage* / Q000494:pharmacology; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*
D017931:DNA Primers; D005223:Fats; D016209:Interleukin-8; D011347:Procollagen; C508960:TGFB1 protein, human; D053773:Transforming Growth Factor beta1; D012643:Selenium