Fragile X Syndrome causes epigenetic disruptions treatable with BET inhibitor Jq1
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE81912 | GEO | 2017/08/18
SECONDARY ACCESSION(S): PRJNA323397
REPOSITORIES: GEO
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Project description:Fragile X Syndrome causes epigenetic disruptions treatable with BET inhibitor Jq1
| PRJNA323397 | ENA
Project description:BET proteins are a group of epigenetic regulators controlling transcription through reading acetylated histone tails and recruiting transcription complexes. They are considered as potential therapeutic targets in many distinct diseases. A novel synthetic bromodomain and extraterminal domain (BET) inhibitor, JQ1, was proved to suppress oncogene transcription and inflammatory responses. The present study was aimed to investigate the effects of JQ1 on inflammatory response and bone destruction in experimental periodontitis. We found that JQ1 significantly suppressed lipopolysaccharide (LPS)-stimulated inflammatory cytokine transcription, including interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α), as well as receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclast markers, such as c-Fos, nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1 (NFATc1), tartrate-resistant acid phosphatase (TRAP) and cathepsin K in vitro. JQ1 also inhibited toll-like receptors 2/4 (TLR2/4) expression and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) phosphorylation and nuclear translocation. Chromatin immunoprecipitation and quantitative polymerase chain reaction (ChIP-qPCR) revealed that JQ1 neutralized BRD4 enrichment at several gene promoter regions, including NF-κB, TNF-α, c-Fos, and NFATc1. In a murine periodontitis model, systemic administration of JQ1 significantly inhibited inflammatory cytokine expression in diseased gingival tissues. Alveolar bone loss was alleviated in JQ1-treated mice because of reduced osteoclasts in periodontal tissues. These unprecedented results suggest the BET inhibitor JQ1 as a prospective new approach for treating periodontitis.
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Project description:Precise regulation of transcription is crucial for the cellular mechanisms underlying memory formation. However, the link between neuronal stimulation and the proteins that directly interact with histone modifications to activate transcription in neurons remains unclear. Brd4 is a member of the bromodomain and extra-terminal domain (BET) protein family, which binds acetylated histones and is a critical regulator of transcription in many cell types, including transcription in response to external cues. Small molecule BET inhibitors are in clinical trials, yet almost nothing is known about Brd4 function in the brain. Here we show that Brd4 mediates the transcriptional regulation underlying learning and memory. The loss of Brd4 function affects critical synaptic proteins, which results in memory deficits in mice but also decreases seizure susceptibility. Thus Brd4 provides a critical link between neuronal activation and the transcriptional responses that occur during memory formation.
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Project description:Merkel cell carcinoma (MCC) is an aggressive neuroendocrine tumor of the skin currently with no cure. In this study, we have first demonstrated that c-Myc overexpression is common in MCC. By targeting c-Myc, bromodomain inhibitors have demonstrated antitumor efficacy in several preclinical human cancer models. Thus, we interrogated the role of c-Myc inhibition in MCC with c-Myc amplification by using the BET inhibitor JQ1. We have uncovered that c-Myc can be regulated by JQ1 in MCC cells with pathologic c-Myc activation. Moreover, JQ1 potently abrogates c-Myc expression in MCC cells and causes marked G1 cell-cycle arrest. Mechanistically, JQ1-induced cell-cycle arrest coincides with downregulation of cyclin D1 and upregulation of p21, p27, and p57, whereas JQ1 exerts no effect on apoptosis in MCC cells. Further knockdown of p21, p27, or p57 by shRNA partially protects cells from JQ1-induced cell-cycle arrest. In addition, c-Myc knockdown by shRNA generates significant cell-cycle arrest, suggesting that c-Myc overexpression plays a role in MCC pathogenesis. Most importantly, JQ1 significantly attenuates tumor growth in xenograft MCC mouse models. Our results provide initial evidence, indicating the potential clinical utility of BET protein inhibitors in the treatment of MCC with pathologic activation of c-Myc.
| S-EPMC4322674 | biostudies-literature
Project description:Cholangiocarcinoma is a life-threatening disease with a poor prognosis. Although genome analysis unraveled some genetic mutation profiles in cholangiocarcinoma, it remains unknown whether such genetic abnormalities relate to the effects of anticancer drugs. Mutations in isocitrate dehydrogenase 1 and 2 (IDH1/2) are exclusively found in almost 20% of intrahepatic cholangiocarcinoma (ICC). Recently, the anticancer effects of BET inhibitors including JQ1 have been shown in various tumors. In the present study, we report that the antigrowth effect of JQ1 differs among ICC cells and IDH1 mutation sensitizes ICC cells to JQ1. RBE cells harboring IDH1 mutation was more sensitive to JQ1 than HuCCT1 or HuH28 cells with wild-type IDH1. JQ1 induced apoptosis only in RBE cells through the upregulation of proapoptotic genes BAX and BIM. We found that the antigrowth effect was not attributed to downregulation of the MYC gene as a well-known target of JQ1 in various cancer cells. Notably, the forced expression of mutant IDH1 successfully sensitized HuCCT1 cells to JQ1. In addition, AGI-5198, a selective inhibitor of mutant IDH1 partially reversed the decrease in viability after JQ1 treatment and also suppressed the JQ1-induced apoptosis in RBE cells. These data suggest that IDH1 mutation contributed to the growth inhibitory effect of JQ1 in RBE cells. Furthermore, given that the effect of mutant IDH1 was not recapitulated in glioblastoma cells, the enhancement of JQ1 sensitivity by IDH1 mutation seems to be specific for ICC cells. Our findings propose a new stratified therapeutic strategy based on IDH1 mutation in ICC.
| S-EPMC6215870 | biostudies-literature
Project description:Maturation of dendritic cells (DCs) is required to induce T cell immunity, whereas immature DCs can induce immune tolerance. Although the transcription factor STAT5 is suggested to participate in DC maturation, its role in this process remains unclear. In this study, we investigated the effect of STAT5 inhibition on LPS-induced maturation of human monocyte-derived DCs (Mo-DCs). We inhibited STAT5 by treating Mo-DCs with JQ1, a selective inhibitor of BET epigenetic readers, which can suppress STAT5 function. We found that JQ1 inhibits LPS-induced STAT5 phosphorylation and nuclear accumulation, thereby attenuating its transcriptional activity in Mo-DCs. The diminished STAT5 activity results in impaired maturation of Mo-DCs, as indicated by defective upregulation of costimulatory molecules and CD83, as well as reduced secretion of IL-12p70. Expression of constitutively activated STAT5 in JQ1-treated Mo-DCs overcomes the effects of JQ1 and enhances the expression of CD86, CD83, and IL-12. The activation of STAT5 in Mo-DCs is mediated by GM-CSF produced following LPS stimulation. Activated STAT5 then leads to increased expression of both GM-CSF and GM-CSFR, triggering an autocrine loop that further enhances STAT5 signaling and enabling Mo-DCs to acquire a more mature phenotype. JQ1 decreases the ability of Mo-DCs to induce allogeneic CD4(+) and CD8(+) T cell proliferation and production of proinflammatory cytokines. Furthermore, JQ1 leads to a reduced generation of inflammatory CD8(+) T cells and decreased Th1 differentiation. Thus, JQ1 impairs LPS-induced Mo-DC maturation by inhibiting STAT5 activity, thereby generating cells that can only weakly stimulate an adaptive-immune response. Therefore, JQ1 could have beneficial effects in treating T cell-mediated inflammatory diseases.
| S-EPMC4369449 | biostudies-literature
Project description:Histone acetylation is essential for memory formation and its deregulation contributes to the pathogenesis of Alzheimer's disease. Thus, targeting histone acetylation is discussed as a novel approach to treat dementia. The histone acetylation landscape is shaped by chromatin writer and eraser proteins, while readers link chromatin state to cellular function. Chromatin readers emerged novel drug targets in cancer research but little is known about the manipulation of readers in the adult brain. Here we tested the effect of JQ1-a small-molecule inhibitor of the chromatin readers BRD2, BRD3, BRD4 and BRDT-on brain function and show that JQ1 is able to enhance cognitive performance and long-term potentiation in wild-type animals and in a mouse model for Alzheimer's disease. Systemic administration of JQ1 elicited a hippocampal gene expression program that is associated with ion channel activity, transcription and DNA repair. Our findings suggest that JQ1 could be used as a therapy against dementia and should be further tested in the context of learning and memory.
| S-EPMC5639246 | biostudies-literature
Project description:The bromodomain and extra-terminal domain inhibitor JQ1 has marked antitumor activity against several hematologic malignancies as well as solid tumor models. Here, we investigated its activity in vitro and in vivo against models of childhood rhabdomyosarcoma and Ewing sarcoma. In vitro, JQ1 (but not the inactive enantiomer JQ1R) inhibited cell proliferation and increased G1 fraction of cells, although there was no correlation between cell line sensitivity and suppression of c-MYC or MYCN. In vivo, xenografts showed significant inhibition of growth during the period of treatment, and rapid regrowth after treatment was stopped, activity typical of antiangiogenic agents. Furthermore, xenografts derived from cell lines intrinsically resistant or sensitive to JQ1 in vitro had similar sensitivity in vivo as xenografts. Further investigation showed that JQ1 reduced tumor vascularization. This was secondary to both drug-induced downregulation of tumor-derived growth factors and direct effects of JQ1 on vascular elements. JQ1 suppressed VEGF-stimulated vascularization of Matrigel plugs in mice, and in vitro suppressed differentiation, proliferation, and invasion of human umbilical cord vascular endothelial cells (HUVEC). In HUVECs, JQ1 partially suppressed c-MYC levels, but dramatically reduced AP-1 levels and activity through suppression of the AP-1-associated protein FOSL1. Our data suggest that the antitumor activity of JQ1 in these sarcoma models is largely a consequence of its antiangiogenic activity. Mol Cancer Ther; 15(5); 1018-28. ©2016 AACR.
| S-EPMC4873398 | biostudies-literature
Project description:Histone acetylation regulates activation and repression of multiple inflammatory genes known to play critical roles in chronic inflammatory diseases. However, proteins responsible for translating the histone acetylation code into an orchestrated proinflammatory cytokine response remain poorly characterized. Bromodomain and extraterminal (BET) proteins are "readers" of histone acetylation marks, with demonstrated roles in gene transcription, but the ability of BET proteins to coordinate the response of inflammatory cytokine genes through translation of histone marks is unknown. We hypothesize that members of the BET family of dual bromodomain-containing transcriptional regulators directly control inflammatory genes. We examined the genetic model of brd2 lo mice, a BET protein hypomorph, to show that Brd2 is essential for proinflammatory cytokine production in macrophages. Studies that use small interfering RNA knockdown and a small-molecule inhibitor of BET protein binding, JQ1, independently demonstrate BET proteins are critical for macrophage inflammatory responses. Furthermore, we show that Brd2 and Brd4 physically associate with the promoters of inflammatory cytokine genes in macrophages. This association is absent in the presence of BET inhibition by JQ1. Finally, we demonstrate that JQ1 ablates cytokine production in vitro and blunts the "cytokine storm" in endotoxemic mice by reducing levels of IL-6 and TNF-? while rescuing mice from LPS-induced death. We propose that targeting BET proteins with small-molecule inhibitors will benefit hyperinflammatory conditions associated with high levels of cytokine production.
| S-EPMC3608815 | biostudies-literature
Project description:As a BET bromodomain inhibitor, JQ1 has been proven have efficacy against a number of different cancers. In terms of male reproduction, JQ1 may be used as a new type of contraceptive, since JQ1 treatment in male mice could lead to germ cell defects and a decrease of sperm motility, moreover, this effect is reversible. However, the mechanism of JQ1 acting on gene regulation in spermatogenesis remains unclear. Here, we performed single-cell RNA sequencing (scRNA-seq) on mouse testes treated with JQ1 or vehicle control to determine the transcriptional regulatory function of JQ1 in spermatogenesis at the single cell resolution. We confirmed that JQ1 treatment could increase the numbers of somatic cells and spermatocytes and decrease the numbers of spermatid cells. Gene Ontology (GO) analysis demonstrated that differentially expressed genes which were down-regulated after JQ1 injection were mainly enriched in "DNA conformation change" biological process in early developmental germ cells and "spermatid development" biological process in spermatid cells. ATAC-seq data further confirmed that JQ1 injection could change the open state of chromatin. In addition, JQ1 could change the numbers of accessible meiotic DNA double-stranded break sites and the types of transcription factor motif that functioned in pachytene spermatocytes and round spermatids. The multi-omics analysis revealed that JQ1 had the ability to regulate gene transcription by changing chromatin conformation in mouse spermatogenesis, which would potentiate the availability of JQ1 in male contraceptive.
| S-EPMC9170580 | biostudies-literature