Project description:Hepatocellular carcinoma (HCC), the fourth leading cause of cancer mortality, develops almost exclusively in patients with chronic liver disease (CLD) and advanced fibrosis. Here we interrogated functions of hepatic stellate cells (HSC), the main source of liver fibroblasts, during hepatocarcinogenPesis. Genetic depletion, activation or inhibition established HSC as tumour-promoting in mouse models of HCC. HSC were enriched in the preneoplastic environment, where they closely interacted with hepatocytes and modulated hepatocarcinogenesis by regulating hepatocyte proliferation and death. Analysis of mouse and human HSC subpopulations and their associated mediators by single cell RNA-sequencing in conjunction with genetic ablation revealed dual functions of HSC in hepatocarcinogenesis. Hepatocyte growth factor, enriched in quiescent and cytokine-producing HSC (cyHSC), protected from hepatocyte death and HCC development. In contrast, type I collagen, enriched in activated myofibroblastic HSC (myHSC), promoted proliferation and tumour development via increased stiffness and TAZ activation in pretumoural hepatocytes and via activation of discoidin domain receptor 1 in established tumours. An increasing HSC dysbalance between cyHSC and myHSC during liver disease progression was associated with elevated HCC risk in patients. In summary, the dynamic shift of HSC subpopulations and their mediators during CLD is associated with a switch from HCC protection to HCC promotion. This SuperSeries is composed of the SubSeries listed below.
Project description:Hepatocellular carcinoma (HCC) develops almost exclusively in patients with chronic liver disease (CLD) and advanced fibrosis. Here we interrogated functions of hepatic stellate cells (HSC), the main source of fibroblasts in the injured liver, during hepatocarcinogenesis. Genetic depletion, activation, or inhibition established HSC as tumour-promoting in different HCC models. HSC were enriched in the non-tumour environment, where they closely interacted with hepatocytes and modulated hepatocarcinogenesis by regulating hepatocyte proliferation and death. Surprisingly, further analysis of mouse and human HSC subpopulations by single cell and single nucleus RNA-sequencing and their associated mediators revealed dual functions of HSC in hepatocarcinogenesis. Hepatocyte growth factor, enriched in quiescent and cytokine-producing HSC (cyHSC), protected from hepatocyte death and HCC development. In contrast, type I collagen, enriched in highly activated myofibroblastic HSC (myHSC), increased stiffness, TAZ activation, and subsequent hepatocyte proliferation, thereby promoting HCC development. An increasing HSC imbalance with decreased protective cyHSC and increased myHSC during liver disease progression was associated with elevated HCC risk in patients. In summary, our data suggest that the dynamic shift of HSC subpopulations during CLD and their mediators is associated with a switch from HCC protection to HCC promotion.
Project description:Hepatic stellate cells (HSCs) are a significant component of the hepatocellular carcinoma (HCC) tumor microenvironment (TME). Activated HSCs transform into myofibroblast-like cells to promote fibrosis in response to liver injury or chronic inflammation, leading to cirrhosis and HCC. The hepatic TME is comprised of cellular components, including activated HSCs, tumor-associated macrophages, endothelial cells, immune cells, and non-cellular components, such as growth factors, proteolytic enzymes and their inhibitors, and other extracellular matrix (ECM) proteins. Interactions between HCC cells and their microenvironment have become topics under active investigation. These interactions within the hepatic TME have the potential to drive carcinogenesis and create challenges in generating effective therapies. Current studies reveal potential mechanisms through which activated HSCs drive hepatocarcinogenesis utilizing matricellular proteins and paracrine crosstalk within the TME. Since activated HSCs are primary secretors of ECM proteins during liver injury and inflammation, they help promote fibrogenesis, infiltrate the HCC stroma, and contribute to HCC development. In this review, we examine several recent studies revealing the roles of HSCs and their clinical implications in the development of fibrosis and cirrhosis within the hepatic TME.
Project description:Background & Aims: Rapid induction of beta-PDGF receptor (beta-PDGFR) is a core feature of hepatic stellate cell activation, the hallmark of liver fibrogenesis. However, biological consequences of the induction are not well characterized. We aimed to determine the involvement of beta-PDGFR-mediated molecular pathway activation on hepatic stellate cells in liver injury, fibrogenesis, and carcinogenesis in vivo. Methods: Loss and constitutive activation of beta-PDGFR were assessed in mouse models with either a stellate cell-specific beta-PDGFR knockout or the expression of an autoactivating mutation respectively. Liver injury and fibrosis were induced in two mechanistically distinct models: carbontetrachloride (CCl4) treatment and ligation of the common bile duct. Hepatocarcinogenesis with underlying liver injury/fibrosis was assessed by a single dose of diethylnitrosamine (DEN) followed by repeated injections of CCl4. Genome-wide expression profiling was performed isolated stellate cells from these models to determine deregulated pathways. Results: Depletion of beta-PDGFR in hepatic stellate cells led to decreased histological liver injury, serum transaminases, collagen alpha 1(I) and alpha smooth muscle actin expression, and collagen deposition. Stellate cell proliferation was significantly reduced after acute hepatic injury in vivo. In contrast, autoactivation of beta-PDGFR in stellate cells accelerated liver fibrosis, most prominently after 6 weeks of CCl4 induced injury. There was no difference in development of DEN-induced pre-neoplastic loci according to the status of beta-PDGFR. Conclusions: Depletion of beta-PDGFR in hepatic stellate cells attenuated the development of liver injury, fibrosis, and stellate cell proliferation in multiple animal models, whereas the constitutive activation of beta-PDGFR enhanced fibrosis. However, manipulation of beta-PDGFR alone did not reduce development of dysplastic nodules. These findings indicate that titration of receptor beta-PDGFR expression on stellate cells parallels fibrosis and injury, but may not impact the development of hepatic neoplasia alone. Hepatic stellate cells were isolated from liver of beta-PDGFR-wild-type or knockout mice, and treated with beta-PDGF ligand or vehicle control.
Project description:Background & Aims: Rapid induction of beta-PDGF receptor (beta-PDGFR) is a core feature of hepatic stellate cell activation, the hallmark of liver fibrogenesis. However, biological consequences of the induction are not well characterized. We aimed to determine the involvement of beta-PDGFR-mediated molecular pathway activation on hepatic stellate cells in liver injury, fibrogenesis, and carcinogenesis in vivo. Methods: Loss and constitutive activation of beta-PDGFR were assessed in mouse models with either a stellate cell-specific beta-PDGFR knockout or the expression of an autoactivating mutation respectively. Liver injury and fibrosis were induced in two mechanistically distinct models: carbontetrachloride (CCl4) treatment and ligation of the common bile duct. Hepatocarcinogenesis with underlying liver injury/fibrosis was assessed by a single dose of diethylnitrosamine (DEN) followed by repeated injections of CCl4. Genome-wide expression profiling was performed isolated stellate cells from these models to determine deregulated pathways. Results: Depletion of beta-PDGFR in hepatic stellate cells led to decreased histological liver injury, serum transaminases, collagen alpha 1(I) and alpha smooth muscle actin expression, and collagen deposition. Stellate cell proliferation was significantly reduced after acute hepatic injury in vivo. In contrast, autoactivation of beta-PDGFR in stellate cells accelerated liver fibrosis, most prominently after 6 weeks of CCl4 induced injury. There was no difference in development of DEN-induced pre-neoplastic loci according to the status of beta-PDGFR. Conclusions: Depletion of beta-PDGFR in hepatic stellate cells attenuated the development of liver injury, fibrosis, and stellate cell proliferation in multiple animal models, whereas the constitutive activation of beta-PDGFR enhanced fibrosis. However, manipulation of beta-PDGFR alone did not reduce development of dysplastic nodules. These findings indicate that titration of receptor beta-PDGFR expression on stellate cells parallels fibrosis and injury, but may not impact the development of hepatic neoplasia alone.
Project description:Hepatocellular carcinoma (HCC), the fourth leading cause of cancer mortality, develops almost exclusively in patients with chronic liver disease (CLD) and advanced fibrosis. Here we interrogated functions of hepatic stellate cells (HSC), the main source of liver fibroblasts, during hepatocarcinogenPesis. Genetic depletion, activation or inhibition established HSC as tumour-promoting in mouse models of HCC. HSC were enriched in the preneoplastic environment, where they closely interacted with hepatocytes and modulated hepatocarcinogenesis by regulating hepatocyte proliferation and death. Analysis of mouse and human HSC subpopulations and their associated mediators by single cell RNA-sequencing in conjunction with genetic ablation revealed dual functions of HSC in hepatocarcinogenesis. Hepatocyte growth factor, enriched in quiescent and cytokine-producing HSC (cyHSC), protected from hepatocyte death and HCC development. In contrast, type I collagen, enriched in activated myofibroblastic HSC (myHSC), promoted proliferation and tumour development via increased stiffness and TAZ activation in pretumoural hepatocytes and via activation of discoidin domain receptor 1 in established tumours. An increasing HSC dysbalance between cyHSC and myHSC during liver disease progression was associated with elevated HCC risk in patients. In summary, the dynamic shift of HSC subpopulations and their mediators during CLD is associated with a switch from HCC protection to HCC promotion.
Project description:Hepatocellular carcinoma (HCC) emerges from chronic inflammation to which activation of hepatic stellate cells (HSCs) contributes by shaping a pro-tumorigenic microenvironment. Key to this process is p62, whose inactivation leads to enhanced hepatocarcinogenesis. Here, we show that while p62 positively regulates STING ubiquitination by TRIM32 by displacing NBR1, which results in the activation of the interferon (IFN) cascade, NBR1 prevents TRIM32 interaction with and the activation of STING, leading to impaired IFN synthesis. NBR1 also antagonizes STING function by promoting its trafficking from the Golgi to the endosome-lysosomal degradative cascade independent of autophagy. Importantly, NBR1 deletion completely reverts the tumor-promoting function of p62-deficient HSCs. The upregulation of the STING-IFN pathway by NBR1 deficiency enhances the anti-tumor response mediated by CD8+ T cells. These results identify NBR1 as a synthetic vulnerability of p62-deficiency in HSCs. NBR1 loss, by promoting the STING/IFN pathway, boosts anti-tumor CD8+ T cell responses to restrain HCC.
Project description:Hepatocellular carcinoma (HCC) emerges from chronic inflammation to which activation of hepatic stellate cells (HSCs) contributes by shaping a pro-tumorigenic microenvironment. Key to this process is p62, whose inactivation leads to enhanced hepatocarcinogenesis. Here, we show that while p62 positively regulates STING ubiquitination by TRIM32 by displacing NBR1, which results in the activation of the interferon (IFN) cascade, NBR1 prevents TRIM32 interaction with and the activation of STING, leading to impaired IFN synthesis. NBR1 also antagonizes STING function by promoting its trafficking from the Golgi to the endosome-lysosomal degradative cascade independent of autophagy. Importantly, NBR1 deletion completely reverts the tumor-promoting function of p62-deficient HSCs. The upregulation of the STING-IFN pathway by NBR1 deficiency enhances the anti-tumor response mediated by CD8+ T cells. These results identify NBR1 as a synthetic vulnerability of p62-deficiency in HSCs. NBR1 loss, by promoting the STING/IFN pathway, boosts anti-tumor CD8+ T cell responses to restrain HCC.
Project description:Our previous studies have found that LOX and LOXL1 were highly upregulated in advanced liver fibrosis; herein, we aimed to investigate the roles of LOX and LOXL1 in hepatic stellate cells.