Decitabine activates type I interferon signaling to inhibit p53-deficient myeloid malignant cells.
Ontology highlight
ABSTRACT:
SUBMITTER: Wu J
PROVIDER: S-EPMC8571953 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:The ongoing epidemic of Zika virus (ZIKV) illustrates the importance of flaviviruses as emerging human pathogens. All vector-borne flaviviruses studied thus far have to overcome type I interferon (IFN) to replicate and cause disease in vertebrates. The mechanism(s) by which ZIKV antagonizes IFN signaling is unknown. Here, we report that the nonstructural protein NS5 of ZIKV and other flaviviruses examined could suppress IFN signaling, but through different mechanisms. ZIKV NS5 expression resulted in proteasomal degradation of the IFN-regulated transcriptional activator STAT2 from humans, but not mice, which may explain the requirement for IFN deficiency to observe ZIKV-induced disease in mice. The mechanism of ZIKV NS5 resembles dengue virus (DENV) NS5 and not its closer relative, Spondweni virus (SPOV). However, unlike DENV, ZIKV did not require the E3 ubiquitin ligase UBR4 to induce STAT2 degradation. Hence, flavivirus NS5 proteins exhibit a remarkable functional convergence in IFN antagonism, albeit by virus-specific mechanisms.
| S-EPMC4900918 | biostudies-literature
Project description:Environmental factors contribute to the development of autoimmune diseases, including systemic lupus erythematosus (SLE), which exhibits a strong female bias (female-to-male ratio 9:1). However, the molecular mechanisms remain largely unknown. Because a feedforward loop between the female sex hormone estrogen (E2) and type I interferon (IFN-α/β)-signaling induces the expression of certain p200-family proteins (such as murine p202 and human IFI16) that regulate innate immune responses and modify lupus susceptibility, we investigated whether treatment of myeloid cells with bisphenol A (BPA), an environmental estrogen, could regulate the p200-family proteins and activate innate immune responses. We found that treatment of murine bone marrow-derived cells (BMCs) and human peripheral blood mononuclear cells with BPA induced the expression of ERα and IFN-β, activated the IFN-signaling, and stimulated the expression of the p202 and IFI16 proteins. Further, the treatment increased levels of the NLRP3 inflammasome and stimulated its activity. Accordingly, BPA-treatment of BMCs from non lupus-prone C57BL/6 and the lupus-prone (NZB×NZW)F1 mice activated the type I IFN-signaling, induced the expression of p202, and activated an inflammasome activity. Our study demonstrates that BPA-induced signaling in the murine and human myeloid cells stimulates the type I IFN-signaling that results in an induction of the p202 and IFI16 innate immune sensors for the cytosolic DNA and activates an inflammasome activity. These observations provide novel molecular insights into the role of environmental BPA exposures in potentiating the development of certain autoimmune diseases such as SLE.
| S-EPMC4581997 | biostudies-literature
Project description:PD-1 (Programmed cell death protein 1) regulates the metabolic reprogramming of myeloid-derived suppressor cells and myeloid cell differentiation, as well as the type I interferon (IFN-I) signaling pathway in myeloid cells in the tumor microenvironment. PD-1, therefore, is a key inhibitory receptor in myeloid cells. However, the regulation of PD-1 expression in myeloid cells is unknown. We report that the expression level of PDCD1, the gene that encodes the PD-1 protein, is positively correlated with the levels of IFNB1 and IFNAR1 in myeloid cells in human colorectal cancer. Treatment of mouse myeloid cell lines with recombinant IFNβ protein elevated PD-1 expression in myeloid cells in vitro. Knocking out IFNAR1, the gene that encodes the IFN-I-specific receptor, diminished the inductive effect of IFNβ on PD-1 expression in myeloid cells in vitro. Treatment of tumor-bearing mice with a lipid nanoparticle-encapsulated IFNβ-encoding plasmid (IFNBCOL01) increased IFNβ expression, resulting in elevated PD-1 expression in tumor-infiltrating myeloid cells. At the molecular level, we determined that IFNβ activates STAT1 (signal transducer and activator of transcription 1) and IRFs (interferon regulatory factors) in myeloid cells. Analysis of the cd279 promoter identified IRF2-binding consensus sequence elements. ChIP (chromatin immunoprecipitation) analysis determined that the pSTAT1 directly binds to the irf2 promoter and that IRF2 directly binds to the cd279 promoter in myeloid cells in vitro and in vivo. In colon cancer patients, the expression levels of STAT1, IRF2 and PDCD1 are positively correlated in tumor-infiltrating myeloid cells. Our findings determine that IFNβ activates PD-1 expression at least in part by an autocrine mechanism via the stimulation of the pSTAT1-IRF2 axis in myeloid cells.
| S-EPMC11240780 | biostudies-literature
Project description:MAVS signalosome plays an important role in RIG-I-like receptor (RLR)-induced antiviral signaling. Upon the recognition of viral RNAs, RLRs activate MAVS, which further recruits TRAF6 and other signaling proteins to initiate type I interferon (IFN) activation. MAVS signalosome also regulates virus-induced apoptosis to limit viral replication. However, the mechanisms that control the activity of MAVS signalosome are still poorly defined. Here, we report NLRP11, a Nod-like receptor, is induced by type I IFN and translocates to mitochondria to interact with MAVS upon viral infection. Using MAVS as a platform, NLRP11 degrades TRAF6 to attenuate the production of type I IFNs as well as virus-induced apoptosis. Our findings reveal the regulatory role of NLRP11 in antiviral immunity by disrupting MAVS signalosome.
| S-EPMC5709773 | biostudies-literature
Project description:Despite advancements in cancer therapeutics, acute myeloid leukemia patients over 60 years old have a 5-year survival rate of less than 8%. In an attempt to improve this, epigenetic modifying agents have been combined as therapies in clinical studies. In particular combinations with Decitabine and Vorinostat have had varying degrees of efficacy. This study therefore aimed to understand the underlying molecular mechanisms of these agents to identify potential rational epi-sensitized combinations. Combined Decitabine-Vorinostat treatment synergistically decreased cell proliferation, induced apoptosis, enhanced acetylation of histones and further decreased DNMT1 protein with HL-60 cells showing a greater sensitivity to the combined treatment than OCI-AML3. Combination therapy led to reprogramming of unique target genes including AXL, a receptor tyrosine kinase associated with cell survival and a poor prognosis in AML, which was significantly upregulated following treatment. Therefore targeting AXL following epi-sensitization with Decitabine and Vorinostat may be a suitable triple combination. To test this, cells were treated with a novel triple combination therapy including BGB324, an AXL specific inhibitor. Triple combination increased the sensitivity of OCI-AML3 cells to Decitabine and Vorinostat as shown through viability assays and significantly extended the survival of mice transplanted with pretreated OCI-AML3 cells, while bioluminescence imaging showed the decrease in disease burden following triple combination treatment. Further investigation is required to optimize this triple combination, however, these results suggest that AXL is a potential marker of response to Decitabine-Vorinostat combination treatment and offers a new avenue of epigenetic combination therapies for acute myeloid leukemia.
| S-EPMC5584259 | biostudies-literature
Project description:Nod-like receptors (NLRs) are intracellular sensors that respond to a variety of pathogen and intracellular danger signals to induce innate immune responses. NLRC5 has recently been identified to be an important regulator of NF-?B, type I interferon (IFN) and inflammasome signaling pathways, but the in vivo function and mechanisms of NLRC5 remain to be defined. Here, we describe the generation and characterization of NLRC5 knockout mice. We show that induction of NLRC5 expression by Toll-like receptor (TLR) ligand or cytokine stimulation requires the signal transducers and activators of transcription (Stat)1-mediated signaling pathway. NLRC5 ablation reduces MHC class I expression, and enhances IKK and IRF3 phosphorylation in response to TLR stimulation or viral infection. Consistent with these observations, we found that NLRC5 deficiency enhanced IL-6 and IFN-? production in mouse embryonic fibroblasts (MEFs), peritoneal macrophages and bone marrow-derived macrophages (BMMs), but not bone marrow-derived dendritic cells (BMDCs) after LPS stimulation or vesicular stomatitis virus (VSV) infection. Furthermore, we found that NLRC5-deficient mice produced higher amounts of IL-6 and IFN-? in the sera when they were challenged with LPS or infected with VSV. Taken together, these results provide in vivo evidence that NLRC5 plays critical roles in MHC class I expression, innate immune signaling and antiviral innate immune responses, thus serving as an important target for modulating innate immune signaling and regulation.
| S-EPMC3343662 | biostudies-literature
Project description:ObjectivesThis study was to explore the effect of protein phosphatase, Mg2+/Mn2+ dependent 1D knockdown on proliferation and apoptosis as well as p38 MAPK/p53 signaling pathway in acute myeloid leukemia.MethodsThe expression of protein phosphatase, Mg2+/Mn2+ dependent 1D was detected in acute myeloid leukemia cell lines including SKM-1, KG-1, AML-193, and THP-1 cells, and normal bone marrow mononuclear cells isolated from healthy donors. The knockdown of protein phosphatase, Mg2+/Mn2+ dependent 1D was conducted by transfecting small interfering RNA into AML-193 cells and KG-1 cells.ResultsThe relative messenger RNA/protein expressions of protein phosphatase, Mg2+/Mn2+ dependent 1D were higher in SKM-1, KG-1, AML-193, and THP-1 cells compared with control cells (normal bone marrow mononuclear cells). After transfecting protein phosphatase, Mg2+/Mn2+ dependent 1D small interfering RNA into AML-193 cells and KG-1 cells, both messenger RNA and protein expressions of protein phosphatase, Mg2+/Mn2+ dependent 1D were significantly reduced, indicating the successful transfection. Most importantly, knockdown of protein phosphatase, Mg2+/Mn2+ dependent 1D suppressed cell proliferation and promoted cell apoptosis in AML-193 cells and KG-1 cells. In addition, knockdown of protein phosphatase, Mg2+/Mn2+ dependent 1D enhanced the expressions of p-p38 and p53 in AML-193 cells and KG-1 cells. The above observation suggested that protein phosphatase, Mg2+/Mn2+ dependent 1D knockdown suppressed cell proliferation, promoted cell apoptosis, and activated p38 MAPK/p53 signaling pathway in acute myeloid leukemia cells.ConclusionProtein phosphatase, Mg2+/Mn2+ dependent 1D is implicated in acute myeloid leukemia carcinogenesis, which illuminates its potential role as a treatment target for acute myeloid leukemia.
| S-EPMC7375723 | biostudies-literature
Project description:Activation of the type I interferon (IFN) signaling pathway is essential for the eradication of hepatitis C virus (HCV). Metformin can activate adenosine monophosphate-activated protein kinase (AMPK) to reduce insulin resistance. Cross talks between AMPK and IFN signaling remain unclear. To understand the influence of metformin on the type I IFN signaling pathway and HCV infection, the full-length HCV replicon OR6 cells and the infectious HCV clones JFH1 were used to assess the anti-HCV effect of the insulin sensitizers, metformin and pioglitazone. Immunofluorescence staining and the immunoblotting of HCV viral protein demonstrated that metformin, but not pioglitazone, inhibited HCV replication in OR-6 and JFH-1-infected Huh 7.5.1 cells. Immunoblotting data showed that metformin activated the phosphorylation of STAT-1 and STAT-2 in OR-6 and JFH-1 infected Huh 7.5.1 cells. Metformin enhanced the phosphorylation of AMPK, and the metformin-activated IFN signaling was down-regulated by AMPK inhibitor. After treatment of AMPK inhibitor, the level of HCV core protein decreased by metformin can be rescued. In conclusion, metformin activates type I interferon signaling and inhibits the replication of HCV via activation of AMPK.
| S-EPMC5696152 | biostudies-literature
Project description:The tumor suppressor p53 transcriptionally activates target genes to suppress cellular proliferation during stress. p53 has also been implicated in the repression of the proto-oncogene Myc, but the mechanism has remained unclear. Here, we identify Pvt1b, a p53-dependent isoform of the long noncoding RNA (lncRNA) Pvt1, expressed 50 kb downstream of Myc, which becomes induced by DNA damage or oncogenic signaling and accumulates near its site of transcription. We show that production of the Pvt1b RNA is necessary and sufficient to suppress Myc transcription in cis without altering the chromatin organization of the locus. Inhibition of Pvt1b increases Myc levels and transcriptional activity and promotes cellular proliferation. Furthermore, Pvt1b loss accelerates tumor growth, but not tumor progression, in an autochthonous mouse model of lung cancer. These findings demonstrate that Pvt1b acts at the intersection of the p53 and Myc transcriptional networks to reinforce the anti-proliferative activities of p53.
| S-EPMC7184554 | biostudies-literature
Project description:The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel human coronavirus causing the pandemic of severe pneumonia (Coronavirus Disease 2019, COVID-19). SARS-CoV-2 is highly pathogenic in human, having posed immeasurable public health challenges to the world. Innate immune response is critical for the host defense against viral infection and the dysregulation of the host innate immune responses probably aggravates SARS-CoV-2 infection, contributing to the high morbidity and lethality of COVID-19. It has been reported that some coronavirus proteins play an important role in modulating innate immunity of the host, but few studies have been conducted on SARS-CoV-2. In this study, we screened the viral proteins of SARS-CoV-2 and found that the viral ORF6, ORF8 and nucleocapsid proteins were potential inhibitors of type I interferon signaling pathway, a key component for antiviral response of host innate immune. All the three proteins showed strong inhibition on type I interferon (IFN-β) and NF-κB-responsive promoter, further examination revealed that these proteins were able to inhibit the interferon-stimulated response element (ISRE) after infection with Sendai virus, while only ORF6 and ORF8 proteins were able to inhibit the ISRE after treatment with interferon beta. These findings would be helpful for the further study of the detailed signaling pathway and unveil the key molecular player that may be targeted.
| S-EPMC7309931 | biostudies-literature