To gain insight into pathogenic mechanisms underlying fibrosis in hepatitis C virus (HCV)-mediated liver injury, we compared intrahepatic gene expression profiles in HCV-infe-cted patients at different stages of fibro...To gain insight into pathogenic mechanisms underlying fibrosis in hepatitis C virus (HCV)-mediated liver injury, we compared intrahepatic gene expression profiles in HCV-infe-cted patients at different stages of fibrosis and α -smooth muscle actin (α - SMA) staining patterns. We studied 21 liver biopsy specimens: 5 had no fibrosis (Ludwig-Batts stage 0); 10 had early portal or periportal fibrosis (stages 1 and 2); and 6, advanced fibrosis (stages 3 and 4). None of the patients had hepatocellular carcinoma. Transcriptional profiles were determined by highdensity oligonucleotide microarrays. ANOVA identified 157 genes for which transcript abundance was associated with fibrosis stage. These defined three distinct hierarchical clusters of patients. Patients with predominantly stage 0 fibrosis had increased abundance of mRNAs linked to glycolipid metabolism. PDGF, a potent stellate cell mitogen, was also increased. Transcripts with increased abundance in stages 1 and 2 fibrosis were associated with oxidative stress, apoptosis, inflammation, proliferation, and matrix degradation, whereas transcripts increased in stages 3 and 4 were associated with fibrogenesis and cellular proliferation. Cells staining for α -SMA were detectable at all stages but infrequent in advanced fibrosis without active inflammation. A high frequency of such cells was associated with mRNAs linked to glycolipid metabolism. In conclusion, the presence of α -SMA-positive HSCs and expression of PDGF in stage 0 fibrosis suggests that stellate cells are activated early in HCV-mediated injury, possibly in response to oxidative stress resulting from inflammation and lipid metabolism. Increased abundance of transcripts linked to cellular proliferation in advanced fibrosis is consistent with a predisposition to cancer.展开更多
文摘To gain insight into pathogenic mechanisms underlying fibrosis in hepatitis C virus (HCV)-mediated liver injury, we compared intrahepatic gene expression profiles in HCV-infe-cted patients at different stages of fibrosis and α -smooth muscle actin (α - SMA) staining patterns. We studied 21 liver biopsy specimens: 5 had no fibrosis (Ludwig-Batts stage 0); 10 had early portal or periportal fibrosis (stages 1 and 2); and 6, advanced fibrosis (stages 3 and 4). None of the patients had hepatocellular carcinoma. Transcriptional profiles were determined by highdensity oligonucleotide microarrays. ANOVA identified 157 genes for which transcript abundance was associated with fibrosis stage. These defined three distinct hierarchical clusters of patients. Patients with predominantly stage 0 fibrosis had increased abundance of mRNAs linked to glycolipid metabolism. PDGF, a potent stellate cell mitogen, was also increased. Transcripts with increased abundance in stages 1 and 2 fibrosis were associated with oxidative stress, apoptosis, inflammation, proliferation, and matrix degradation, whereas transcripts increased in stages 3 and 4 were associated with fibrogenesis and cellular proliferation. Cells staining for α -SMA were detectable at all stages but infrequent in advanced fibrosis without active inflammation. A high frequency of such cells was associated with mRNAs linked to glycolipid metabolism. In conclusion, the presence of α -SMA-positive HSCs and expression of PDGF in stage 0 fibrosis suggests that stellate cells are activated early in HCV-mediated injury, possibly in response to oxidative stress resulting from inflammation and lipid metabolism. Increased abundance of transcripts linked to cellular proliferation in advanced fibrosis is consistent with a predisposition to cancer.
