Project description:Hepatitis B virus (HBV)-associated acute liver failure (ALF) is a dramatic clinical syndrome due to a sudden loss of hepatic cells leading to multiorgan failure. The mechanisms whereby HBV induces ALF are unknown. We used gene expression profiling to establish a molecular definition of hepatitis B virus (HBV)-associated ALF. Two patients who underwent liver transplantation for HBV-associated ALF were studied. Gene expression profiling was performed on 8 liver specimens obtained from the two patients with ALF (4 samples per liver) and individual liver specimens from 8 liver donors and normal livers from 11 patients who underwent resection for angioma. Statistical analyses were used to identify the signature genes of HBV-associated ALF. Multivariate permutation analysis identified 1,368 transcripts that were differentially expressed in ALF; 709 were up-regulated and 659 down-regulated. The most represented up-regulated transcripts were those involved in the immune response, whereas the most abundant down-regulated transcripts were those involved in metabolism and hepatic synthesis. ALF was characterized by overriding B-cell signature comprising genes related to mature B cells and plasma cells with abundant polyclonal expression of immunoglobulin genes. By contrast, there was a limited T-cell signature and up-regulation of several inhibitors of T-cell activation. Immunohistochemical analysis confirmed the prominent B-cell signature showing diffuse liver infiltration by plasma blasts and plasma cells with strong cytoplasmic staining for IgM and IgG, associated with a significant deposition of complement factors. Using phage display technology, we demonstrated that the molecular target of the massive intrahepatic antibody response is the hepatitis B core antigen (HBcAg). These data suggest that the humoral immunity may exert a primary role in the pathogenesis of HBV-associated ALF. Liver samples were obtained from explanted livers of two patients with HBV-associated ALF (4 samples per liver), 8 normal liver donors and 11 patients who underwent resection for angioma. Gene expression profiling was used to establish a molecular definition of ALF. Patient data derived from associated publication Table S2. This dataset is part of the TransQST collection.

Project description:The liver has inherent regenerative capacity via mitotic division of mature hepatocytes. However, if the hepatic loss is massive or mature hepatocyte proliferation is impaired by chronic liver injury, HSPC are activated to support liver regeneration. Access to liver tissue from 4 patients who underwent liver transplantation for hepatitis B virus (HBV)- associated acute liver failure (ALF) provided us with the opportunity to investigate the molecular mechanisms of liver regeneration in humans by means of gene expression profiling and immunohistochemistry (IHC). Gene expression profiling of 17 liver specimens from the 4 ALF cases and individual liver specimens from 10 liver donors documented a distinct gene signature for ALF. However, unsupervised multidimensional scaling and hierarchical clustering identified two-well defined clusters that segregated according to the histopathological severity, i.e. massive hepatic necrosis (MHN; 2 patients) and submassive hepatic necrosis (SHN; 2 patients). We found that ALF is characterized by a strong hepatic stem/progenitor cell (HSPC) gene signature, as also confirmed by IHC, along with ductular reaction, both of which are more prominent in MHN. Interestingly, no evidence of further lineage differentiation was seen in MHN, whereas in SHN we detected cells with hepatocyte-like morphology. Strikingly, ALF was associated with a strong tumorigenesis gene signature. MHN had the greatest upregulation of cancer stem cell genes (EpCAM, CK19 and CK7), whereas the most upregulated genes in SHN were related to cellular growth and proliferation (AKR1B10, NQO1, RRM2, SFN, TOP2A, CCNB1, CDC20, ANLN and KI67). The extent of liver necrosis correlated with an overriding fibrogenesis gene signature, reflecting the wound healing process. Conclusion: Our data provide evidence of marked HSPC cell activation and fibrogenesis in HBV-associated ALF, which positively correlate with the extent of liver necrosis. Moreover, we detected a strong tumorigenesis gene signature in ALF, which underlines the relationship between liver regeneration and liver cancer. Liver samples were obtained from explanted liver of four patients with HBV-associated acute liver failure (4-5 samples per liver) and 10 individual normal liver donors and gene expression profiling was used to establish a molecular definition of this disease. This dataset is part of the TransQST collection.

Project description:The liver has inherent regenerative capacity via mitotic division of mature hepatocytes. However, if the hepatic loss is massive or mature hepatocyte proliferation is impaired by chronic liver injury, HSPC are activated to support liver regeneration. Access to liver tissue from 4 patients who underwent liver transplantation for hepatitis B virus (HBV)- associated acute liver failure (ALF) provided us with the opportunity to investigate the molecular mechanisms of liver regeneration in humans by means of gene expression profiling and immunohistochemistry (IHC). Gene expression profiling of 17 liver specimens from the 4 ALF cases and individual liver specimens from 10 liver donors documented a distinct gene signature for ALF. However, unsupervised multidimensional scaling and hierarchical clustering identified two-well defined clusters that segregated according to the histopathological severity, i.e. massive hepatic necrosis (MHN; 2 patients) and submassive hepatic necrosis (SHN; 2 patients). We found that ALF is characterized by a strong hepatic stem/progenitor cell (HSPC) gene signature, as also confirmed by IHC, along with ductular reaction, both of which are more prominent in MHN. Interestingly, no evidence of further lineage differentiation was seen in MHN, whereas in SHN we detected cells with hepatocyte-like morphology. Strikingly, ALF was associated with a strong tumorigenesis gene signature. MHN had the greatest upregulation of cancer stem cell genes (EpCAM, CK19 and CK7), whereas the most upregulated genes in SHN were related to cellular growth and proliferation (AKR1B10, NQO1, RRM2, SFN, TOP2A, CCNB1, CDC20, ANLN and KI67). The extent of liver necrosis correlated with an overriding fibrogenesis gene signature, reflecting the wound healing process. Conclusion: Our data provide evidence of marked HSPC cell activation and fibrogenesis in HBV-associated ALF, which positively correlate with the extent of liver necrosis. Moreover, we detected a strong tumorigenesis gene signature in ALF, which underlines the relationship between liver regeneration and liver cancer.

Dataset Information

B-Cell Gene Signature with Massive Intrahepatic Production of Antibodies to Hepatitis B Core Antigen in HBV-Associated Acute Liver Failure

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