Hepatocytic p62 suppresses ductular reaction and tumorigenesis in mouse livers with mTORC1 activation and defective autophagy
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE186783 | GEO | 2021/12/14
REPOSITORIES: GEO
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Project description:Background & aimsEither activation of mTORC1 due to loss of Tsc1 (tuberous sclerosis complex 1) or defective hepatic autophagy due to loss of Atg5 leads to spontaneous liver tumorigenesis in mice. The purpose of this study was to investigate the mechanisms by which autophagy contributes to the hepatic metabolic changes and tumorigenesis mediated by mTORC1 activation.MethodsAtg5 Flox/Flox (Atg5F/F) and Tsc1F/F mice were crossed with albumin-Cre mice to generate liver-specific Atg5 knockout (L-Atg5 KO), L-Tsc1 KO and L-Atg5/Tsc1 double KO (DKO) mice. These mice were crossed with p62/Sqstm1F/F (p62) and whole body Nrf2 KO mice to generate L-Atg5/Tsc1/p62 and L-Atg5/Tsc1-Nrf2 triple KO mice. These mice were housed for various periods up to 12 months, and blood and liver tissues were harvested for biochemical and histological analysis RESULTS: Deletion of Atg5 in L-Tsc1 KO mice inhibited liver tumorigenesis but increased mortality and was accompanied by drastically enhanced hepatic ductular reaction (DR), hepatocyte degeneration and metabolic reprogramming. Deletion of p62 reversed DR, hepatocyte degeneration and metabolic reprogramming as well as the mortality of L-Atg5/Tsc1 DKO mice, but unexpectedly promoted liver tumorigenesis via activation of a group of oncogenic signaling pathways. Nrf2 ablation markedly improved DR with increased hepatocyte population and improved metabolic reprogramming and survival of the L-Atg5/Tsc1 DKO mice without tumor formation. Decreased p62 and increased mTOR activity were also observed in a subset of human hepatocellular carcinomas.ConclusionsThese results reveal previously undescribed functions of hepatic p62 in suppressing tumorigenesis and regulating liver cell repopulation and metabolic reprogramming resulting from persistent mTORC1 activation and defective autophagy.Lay summaryMetabolic liver disease and viral hepatitis are common chronic liver diseases and risk factors of hepatocellular carcinoma, which are often associated with impaired hepatic autophagy and increased mTOR activation. Using multiple genetically engineered mouse models of defective hepatic autophagy and persistent mTOR activation, we dissected the complex mechanisms behind this observation. Our results uncovered an unexpected novel tumor suppressor function of p62/Sqstm1, which regulated liver cell repopulation, ductular reaction and metabolic reprogramming in liver tumorigenesis.
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Project description:Hepatocytic p62 suppresses ductular reaction and tumorigenesis in mouse livers with mTORC1 activation and defective autophagy
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Project description:The aim of the study is to investigate the role and mechanisms of tuberous sclerosis complex 1 (TSC1) and mechanistic target of rapamycin complex 1 (mTORC1) in alcohol associated liver disease Hepatic RNA profiles of WT and hepatic TSC1 KO mice fed with alcohol or control diet using Gao binge alcohol model.
2023-04-25 | GSE230175 | GEO
Project description:miRNA expression of 6h EBSS treatment induced autophagy in Atg5 WT and KO mouse embryonic fibroblasts (MEF) were examined. For the 1st comparison, the control group is Atg5 WT MEF without EBSS treatment, the experiment group is Atg5 KO MEF without EBSS treatment; For the 2nd comparison, the control group is Atg5 WT MEF without EBSS treatment, the experiment group is Atg5 WT MEF with 6h EBSS treatment; For the 3rd comparison, the control group is Atg5 WT MEF with 6h EBSS treatment, the experiment group is Atg5 KO MEF with 6h EBSS treatment.The PIQORTM Analyzer were used for the analysis.
2011-11-21 | E-MTAB-880 | biostudies-arrayexpress
Project description:Ductular reaction (DR) is the hallmark of cholestatic diseases manifested in the proliferation of bile ductules lined by biliary epithelial cells (BECs). It is commonly associated with increased risk of fibrosis and liver failure. The Receptor for Advanced Glycation End Products (RAGE) was identified as a critical mediator of DR during chronic injury. Yet, the direct link between RAGE-mediated DR and fibrosis as well as the mode of interaction between BECs and hepatic stellate cells (HSCs) to drive fibrosis remains elusive. In this study, we aimed to delineate the specific function of RAGE on BECs during DR and its potential association with fibrosis in the context of cholestasis. Employing a biliary lineage tracing cholestatic liver injury mouse model, combined with whole transcriptome sequencing and in vitro analyses, we revealed the central role of BEC-specific Rage activity in fostering a pro-fibrotic milieu. RAGE is predominantly expressed in BECs and contributes to DR. Notch ligand Jagged1 is secreted from activated BECs in a Rage-dependent manner and signals HSCs in trans, eventually enhancing fibrosis during cholestasis.
2025-01-07 | GSE275751 | GEO
Project description:To screen mRNAs specifically regulated by mTORC1, a global mRNA expression profile in colon epithelial cells (CECs) from mice with or without CECs-specific TSC1 knockout (KO) was developed using microarray. Wile-type or CECs-specific TSC1 KO mice with experimental colitis were sacrificed, with CECs harvested and subjected to total RNA extraction.
2015-11-05 | E-GEOD-74674 | biostudies-arrayexpress
Project description:The mechanisms that regulate T cell quiescence are poorly understood. We report that tuberous sclerosis complex 1 (Tsc1) establishes a quiescent program in naïve T cells by controlling cell size, cell cycle entry, and responses to T cell receptor stimulation. Loss of quiescence predisposed Tsc1-deficient T cells to apoptosis that depleted conventional T cells and invariant natural killer T cells. Loss of Tsc1 function dampened in vivo immune responses to bacterial infection. Tsc1-deficient T cells exhibited increased mTORC1 but diminished mTORC2 activities, with mTORC1 activation essential for the disruption of immune homeostasis. Therefore, Tsc1-dependent control of mTOR is crucial in establishing naïve T cell quiescence to facilitate adaptive immune function. Naïve CD4 and CD8 T cells from wild-type and Tsc1-deficient mice (in triplicates each group) were stimulated with or without TCR signaling. RNA was analyzed by microarrays. WT/KO for 0 and 4 hr for CD4 (triplicates), and WT/KO for 0 hr for CD8 (duplicates).
2011-07-11 | E-GEOD-29797 | biostudies-arrayexpress
Project description:Ductular reaction (DR) is usually observed in biliary disorders or various liver disorders, including nonalcoholic fatty liver disease. Few studies have focused on interrupting the DR process in the cholestatic environment. Here, we investigated the impact of reversine on DR in rats that had undergone bile duct ligation (BDL). Cholestatic injury was induced in rats 2 weeks following BDL. DR was assessed with biliary markers by immunohistochemistry. Biliary epithelial cells (BECs) were isolated for the analysis of proliferation and biliary factor gene expression. The effects of reversine on DR and fibrosis were analyzed in vivo via intraperitoneal injection in rats for 2 weeks. Chemically-induced BEC formation was used to investigate the biliary markers affected by reversine in vitro. DR with increased BEC expansion was identified in cholestatic liver injury, as indicated by CK7, CK19, and EpCAM expression around the portal vein in BDL rats. BDL-induced DR cells showed the increased expression of genes regulating cell proliferation (Ki67, Foxm1, and Pcna) and biliary markers (Krt7, Krt19, Epcam, Sox9, Cftr, and Asbt). Reversine attenuated cholestatic fibrosis and DR in rats. Reversine affected chemically-induced BEC formation, with the decreased expression of biliary Krt7, Cftr, and Ggt1 genes in vitro. BDL-induced Notch activation was attenuated upon reversine treatment in vivo, in part via the Notch/Sox9 pathway. In conclusion, reversine attenuated cholestatic ductular reaction and fibrosis in rats and reduced the bile duct formation associated with Dlk1/Notch/Sox9 signaling. Reversine may be regarded as a potential drug for cholangiopathies for preventing a ductular reaction.
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Project description:Background & aimsPrimary biliary cholangitis (PBC) is a chronic cholangiopathy characterised by immuno-mediated injury of interlobular bile ducts leading to intrahepatic cholestasis and progressive liver fibrosis. PBC histology is characterised by portal inflammation, progressive fibrosis, ductopenia, and the appearance of the so-called ductular reaction. The aim of the present study was to investigate the pathogenetic relevance of ductular reaction in PBC.MethodsLiver biopsies were collected from naïve people with PBC (N = 87). Clinical-serological parameters were obtained at diagnosis and after 1 year of ursodeoxycholic acid (UDCA) treatment. Histological staging was performed on all slides according to multiple scoring systems and criteria for PBC. Liver samples were obtained from Mdr2 -/- mice treated with or without UDCA. Samples were processed for histology, immunohistochemistry, and immunofluorescence.ResultsDuctular reaction in people with PBC correlated with the disease stage and liver fibrosis, but not with disease activity; an extensive ductular reaction correlated with serum alkaline phosphatase levels at diagnosis, response to UDCA, and individuals' estimated survival, independently from other histological parameters, including disease stage. In people with PBC, reactive ductules were associated with the establishment of junctions with bile canaliculi and with fibrogenetic cell activation. Consistently, in a mouse model of intrahepatic cholestasis, UDCA treatment was effective in reducing ductular reaction and fibrosis and increasing ductular-canalicular junctions.ConclusionsExtensive ductular reaction outlines a severe histologic phenotype in PBC and is associated with an inadequate therapy response and a worse estimated prognosis.Lay summaryIn people affected by primary biliary cholangitis (PBC), the histological appearance of extensive ductular reaction identifies individuals at risk of progressive fibrosis. Ductular reaction at diagnosis correlates with the lack of response to first-line therapy with ursodeoxycholic acid and serves to restore ductular-canalicular junctions in people with PBC. Assessing ductular reaction extension at diagnosis may add valuable information for clinicians.
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Project description:RNAseq was performed by to compare gene expression between wildtype and Smchd1 KO ES cells, the gene expression pattern in Dux KO mutants , Double KO mutant Tet-TKO mutants and Tet TKO plus SMCKHD1 KO mutants were analyzed by RNAseq.
2021-01-27 | GSE126467 | GEO