Dataset Information

Death-Associated Protein 6 (Daxx) Alleviates Liver Fibrosis by Modulating Smad2 Acetylation.

ABSTRACT: Transforming growth factor-β (TGF-β) has been identified as an inducer of hepatocyte epithelial-mesenchymal transition (EMT), which triggers liver fibrosis. Death-associated protein 6 (Daxx) is known to be associated with the TGF-β-induced apoptotic pathway, but the function of Daxx in liver fibrosis remains unknown. This study aimed to elucidate the role of Daxx in liver fibrosis. We used liver fibrosis tissues from humans and mice to assess Daxx expression. EMT properties and TGF-β signaling pathway activation were investigated in the Daxx-overexpressing FL83B cell line. The therapeutic effect of Daxx was investigated in a mouse model of liver fibrosis by the hydrodynamic injection of plasmids. The expression of Daxx was markedly decreased in hepatocytes from fibrotic human and mouse livers, as well as in hepatocytes treated with TGF-β in vitro. The overexpression of Daxx inhibited the EMT process by interfering with the TGF-β-induced phosphorylation of Smad2. Coimmunoprecipitation analysis confirmed that Daxx reduced the transcriptional activity of Smad2 by binding to its MH1 domain and interfering with Smad2 acetylation. In addition, the therapeutic delivery of Daxx alleviated liver fibrosis in a thioacetamide-induced fibrosis mouse model. Overall, our results indicate that Daxx could be a potential therapeutic target to modulate fibrogenesis, as well as a useful biomarker for liver fibrosis.

SUBMITTER: Kim SM

PROVIDER: S-EPMC8305094 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:ObjectiveThe occurrence of liver fibrosis and fibrosis-related liver cancer is the reason for the increase in morbidity and mortality worldwide. Transforming growth factor-β2 (TGF-β2) is an important mediator of chronic liver fibrosis. This study aims to find the molecular mechanism that mediates HBV infection and induces TGF-β2 and verifies that CREB binding protein acetylation mediates HBV infection and induces TGF-β2 expression.MethodsThe acetylated proteins were extracted from HepG2-NTCP cells and HBV-infectedHepG2-NTCP cells. The acetylated proteins were screened by modification enrichment technology and database search. Protein annotation, motif analysis of modification sites, and protein function enrichment analysis of these proteins were performed to roughly clarify the location and function of these acetylated modification proteins in cells. Acylated proteins enriched in the TGF-β pathway were obtained by KEGG pathway enrichment analysis. The effect of the selected acetylated modification protein on the TGF-β pathway was verified by experiments, that is, the target protein gene was knocked out by siRNA, and the expression level of the TGF-β2 was detected by qRT-PCR.ResultsProteins were extracted from HepG2-NTCP cells and HepG2-NTCP cells infected with HBV, and differential acetylation modification proteins were screened. The target protein CREB binding protein was screened by modification enrichment technology and database search. The aggregation analysis of TGF-β pathway showed that CREB binding protein was acetylated at amino acid positions 434 and 439, and enriched in the TGF-β signaling pathway. siRNA targeting CREB binding protein was transfected, and the expression of TGF-β2 in cells was detected by qRT-PCR and western blot, respectively. It was verified that HBV infection-inducedCREB-binding protein acetylation regulated the high expression of TGF-β2.ConclusionAfter HBV infection, CREBBP acetylation was up-regulated, which promoted the high expression of TGF-β2.

Project description:PurposeIn schistosomiasis-associated hepatic fibrosis, the role of murine UL16-binding protein-like transcript 1 (MULT1), the strongest ligand of natural killer group 2-member D receptor (NKG2D), remains unclear. Here, Schistosoma japonicum-infected mice administered with MULT1-encoding DNA were used to test MULT1 as a potential therapy for schistosomiasis-associated hepatic fibrosis and explore relevant mechanisms.Materials and methodsA recombinant plasmid encoding MULT1 (p-rMULT1) was constructed and administered to Schistosoma japonicum-infected BALB/c mice via hydrodynamic tail vein injection. Egg granulomas in liver, hepatic fibrosis biomarkers and levels of cytokines were investigated. Comparisons of CD4+ T, CD8+ T, NK and NKT proportions as well as their phenotype were performed not only between Schistosoma infected, p-rMULT1 treated group and Schistosoma infected, backbone plasmid pEGFP-N1 treated group but also between infected, nontreated group and health control group.ResultsReduced area of granuloma formation and fibrosis around single eggs, downregulated expression of collagen I, α-smooth muscle actin, TGF-β and IL-10, and upregulated expression of IFN-γ, were observed in the livers of p-rMULT1 treated mice. p-rMULT1 treatment improved Schistosoma infection impacted immune microenvironment by modulating proportion of CD4+ T CD8+ T, natural killer (NK) and NKT cells, enhancing expression of NKG2D, in lymphocytes, and augmenting IFN-γ secretion by CD4+ T, CD8+ T, NK and NKT cells, as well as partially reversing some other phenotype changes of lymphocytes.ConclusionTo the best of our knowledge, we provided the first in vivo evidence that MULT1 is a favorable anti-fibrosis factor in the context of schistosomiasis. The inhibitory effect of MULT1 overexpression on schistosomiasis associated with hepatic fibrosis may result from augmenting the proportion and function of NKG2D-expressing immune cells, and from enhancing NK- and T-cell activation, as well as regulating the helper T (Th)1/Th2 balance.

Project description:Ethnopharmacological relevance: Pien-Tze-Huang (PZH)-a traditional Chinese medicine (TCM) compound-has been employed to treat various liver inflammation and tumors for over 10 decades. Interestingly, most of the pharmacological effects had been validated and explored toward liver ailment along with pro-inflammatory conditions and cancer at the cellular and molecular level to date. Aim of the study: The present study aimed to investigate the therapeutic effect of PZH on autophagy and TGF-β1 signaling pathways in rats with liver fibrosis and hepatic stellate cell line (HSC). Materials and methods: Male SD rats with carbon tetrachloride (CCl4)-induced liver fibrosis were used as the animal model. Next, PZH treatment was given for 8 weeks. Afterward, the therapeutic effects of PZH were analyzed through a hepatic tissue structure by hematoxylin-eosin (H&E), Van Gieson (VG) staining, and transmission electron microscopy (TEM), activity of ALT and AST by enzyme-associated immunosorbent assay as well. Subsequently, mRNA and protein expression were examined by quantitative polymerase chain reaction (qPCR), Western blotting, and immunohistochemistry (IHC). Then, the cell vitality of PZH-treated HSC and the expression of key molecules prevailing to autophagy were studied in vitro. Meanwhile, SM16 (a novel small molecular inhibitor which inhibits TGFβ-induced Smad2 phosphorylation) was employed to confirm PZH's effects on the proliferation and autophagy of HSC. Results: PZH pharmacologically exerted anti-hepatic fibrosis effects as demonstrated by protecting hepatocytes and improving hepatic function. The results revealed the reduced production of extracellular collagen by adjusting the balance of matrix metalloproteinase (MMP) 2, MMP9, and tissue inhibitor of matrix metalloproteinase 1 (TIMP1) in PZH-treated CCl4-induced liver fibrosis. Interestingly, PZH inhibited the activation of HSC by down-regulating TGF-β1 and phosphorylating Smad2. Furthermore, PZH down-regulated yeast Atg6 (Beclin-1) and microtubule-associated protein light chain 3 (LC3) toward suppressing HSC autophagy, and PZH exhibited similar effects to that of SM16. Conclusion: To conclude, PZH alleviated CCl4-induced liver fibrosis to reduce the production of extracellular collagen and inhibiting the activation of HSC. In addition, their pharmacological mechanisms related to autophagy and TGF-β1/Smad2 signaling pathways were revealed for the first time.

Dataset Information

Death-Associated Protein 6 (Daxx) Alleviates Liver Fibrosis by Modulating Smad2 Acetylation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets