Project description:Cellular senescence is an irreversible proliferative arrest and can be triggered in many cell types in response to diverse forms of cellular damage or stress. We used microarrays to compare gene expression profile between growing and senescent human activated hepatic stellate cells. Experiment Overall Design: Two separate preparation of activated hepatic stellate cells were treated with DNA damaging agent to induce senescence or vechicle to remain growing. Experiment Overall Design: RNA was extracted from both replications and used for hybridization on Affymetrix arrays to determine expression differences.
Project description:Cellular senescence is an irreversible proliferative arrest and can be triggered in many cell types in response to diverse forms of cellular damage or stress. We used microarrays to compare gene expression profile between growing and senescent human activated hepatic stellate cells. Keywords: cell type comparison
Project description:The molecular determinants of a healthy human liver cell phenotype remain largely uncharacterized. In addition, the gene expression changes associated with activation of primary human hepatic stellate cells, a key event during fibrogenesis, remain poorly characterized. Here, we provide the transriptomic profile underpinning the healthy phenotype of human hepatocytes, liver sinusoidal endothelial cells (LSECs) and quiescent hepatic stellate cells (qHSCs) as well as activated HSCs (aHSCs) We assess the transcriptome for purified, non-cultured human hepatocytes, liver sinusoidal cells (LSECs) and quiescent hepatic stellate cells (qHSCs) as well as culture-activated HSCs (aHSCs). Hepatocytes (n=2 donors), LSECs (n=3), qHSCs (n=3) and in vitro activated HSCs (n=3; from the same donors as the qHSCs and LSECs) were used for this study.
Project description:The p53 protein is a cell-autonomous tumor suppressor that restricts malignant transformation by triggering cell cycle exit or apoptosis. p53 also promotes cellular senescence, a program that triggers a stable cell cycle arrest and can modify the tissue microenvironment through its effect on cell membrane and secretory proteins. Here we show that specific ablation of p53 in hepatic stellate cells, which undergo a process of proliferation and senescence in the fibrogenic response to liver damage, enhances liver cirrhosis, reduces survival and increases the malignant transformation of adjacent epithelial cells into hepatocellular carcinoma. This p53-dependent senescence program involves the release of secreted proteins which skew macrophages into a tumor-inhibiting M1-state that can eliminate senescent stellate cells. In contrast, p53-deficient stellate cells secrete factors that promote M2 polarization, which is pro-tumorigenic. Our study reveals that p53 can exert a non-cell-autonomous tumor suppressor response and suggests that this occurs, in part, by its ability to influence macrophage polarization. We used microarrays to detail the global programme of gene expression underlying p53-dependent senescent and identified distinct classes of up-regulated or down-regulated genes during this process. Proliferating and senescent stellate cell pellets were collected RNA extraction and hybridization on Affymetrix microarrays.