scholarly journals Targeting the Bromodomain of BRG-1/BRM Subunit of the SWI/SNF Complex Increases the Anticancer Activity of Temozolomide in Glioblastoma

2021 ◽  
Vol 14 (9) ◽  
pp. 904
Author(s):  
Chuanhe Yang ◽  
Yinan Wang ◽  
Michelle M. Sims ◽  
Yali He ◽  
Duane D. Miller ◽  
...  
Keyword(s):  
Chromatin Remodeling ◽  
Small Molecule ◽  
Therapeutic Potential ◽  
Standard Of Care ◽  
Anticancer Effect ◽  
Altered Gene Expression ◽  
Chromatin Remodeling Complex ◽  
Novel Targets ◽  
Altered Gene

Glioblastoma (GBM) is a deadly and incurable brain cancer with limited therapeutic options. PFI-3 is a small-molecule bromodomain (BRD) inhibitor of the BRM/BRG1 subunits of the SWI/SNF chromatin remodeling complex. The objective of this study is to determine the efficacy of PFI-3 as a potential GBM therapy. We report that PFI-3 binds to these BRDs when expressed in GBM cells. PFI-3 markedly enhanced the antiproliferative and cell death-inducing effects of temozolomide (TMZ) in TMZ-sensitive GBM cells as well as overcame the chemoresistance of highly TMZ-resistant GBM cells. PFI-3 also altered gene expression in GBM and enhanced the basal and interferon-induced expression of a subset of interferon-responsive genes. Besides the effects of PFI-3 on GBM cells in vitro, we found that PFI-3 markedly potentiated the anticancer effect of TMZ in an intracranial GBM animal model, resulting in a marked increase in survival of animals bearing GBM tumors. Taken together, we identified the BRG1 and BRM subunits of SWI/SNF as novel targets in GBM and revealed the therapeutic potential of applying small molecule inhibitors of SWI/SNF to improve the clinical outcome in GBM using standard-of-care chemotherapy.

scholarly journals Functional Coupling between HIV-1 Integrase and the SWI/SNF Chromatin Remodeling Complex for Efficient in vitro Integration into Stable Nucleosomes

2011 ◽  
Vol 7 (2) ◽  
pp. e1001280 ◽  
Author(s):  
Paul Lesbats ◽  
Yair Botbol ◽  
Guillaume Chevereau ◽  
Cédric Vaillant ◽  
Christina Calmels ◽  
...  
Keyword(s):  
Chromatin Remodeling ◽  
Functional Coupling ◽  
Chromatin Remodeling Complex ◽  
Hiv 1

Abstract 319: Small Molecule Gβγ Inhibition Attenuates Cardiac Fibroblast Inflammatory and Pro-Fibrotic Signaling

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Joshua G Travers ◽  
Fadia A Kamal ◽  
Michael S Burhans ◽  
Burns C Blaxall
Keyword(s):  
Myocardial Fibrosis ◽  
Inflammatory Cytokines ◽  
Small Molecule ◽  
Therapeutic Potential ◽  
Interstitial Fibrosis ◽  
Pressure Overload ◽  
Cardiac Fibroblast ◽  
Ventricular Compliance ◽  
Pro Inflammatory Cytokines

Heart failure (HF) is a devastating disease characterized by chamber remodeling, interstitial fibrosis and reduced ventricular compliance. Prolonged sympathetic overstimulation promotes excess signaling through G-protein Gβγ subunits and ultimately results in pathologic GRK2-mediated β-adrenergic receptor (β-AR) downregulation. We have recently demonstrated the therapeutic potential of the small molecule Gβγ-GRK2 inhibitor Gallein in limiting HF progression. Pathologic activation of the cardiac fibroblast (CF) induces the transition to a myofibroblast phenotype, which plays a fundamental role in myocardial fibrosis and remodeling. We hypothesized that Gβγ-GRK2 inhibition plays an important functional role in the CF to attenuate pathologic CF activation, inflammation and interstitial fibrosis. To explore the effect of Gβγ-GRK2 inhibition on inflammation and pro-fibrotic signaling, mice were subjected to 7 days of transverse aortic constriction, a pressure-overload model of HF. In addition to the attenuation in overall cardiac hypertrophy, animals treated with Gallein displayed reduced expression of pro-inflammatory cytokines, including macrophage inflammatory protein 1 alpha (MIP-1α) and MIP-1β, along with Interleukin-6, as assessed by qPCR. Gallein-treated animals also exhibited diminished pro-fibrotic signaling, as evidenced by a reduction in the expression of TGFβ, a major driver of myocardial fibrosis, and decreased expression of collagen. To recapitulate these findings in vitro, primary adult mouse ventricular fibroblasts were pathologically stimulated using Isoproterenol (ISO, β-AR agonist) or Angiotensin II and treated +/- Gallein for 24 hours. CFs treated with Gallein displayed an analogous reduction in the expression of these pro-inflammatory cytokines and collagen. In summary, these data suggest a potential therapeutic role for small molecule Gβγ-GRK2 inhibition in limiting pathologic myofibroblast activation, inflammation and interstitial fibrosis. We believe this fibroblast-targeted approach will lead to the refinement of existing targets and compounds, and possibly the generation of novel therapeutics for the treatment of HF.

scholarly journals Identification of potential TNF-α inhibitors: from in silico to in vitro studies

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Komal Zia ◽  
Sajda Ashraf ◽  
Almas Jabeen ◽  
Maria Saeed ◽  
Mohammad Nur-e-Alam ◽  
...  
Keyword(s):  
Small Molecule ◽  
Therapeutic Potential ◽  
Pharmacophore Model ◽  
Docking Studies ◽  
Immune Functions ◽  
Binding Interaction ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Potential Inhibitors

AbstractTumor Necrosis Factor Alpha (TNF-α) is a pleiotropic pro-inflammatory cytokine. It act as central biological regulator in critical immune functions, but its dysregulation has been linked with a number of diseases. Inhibition of TNF-α has considerable therapeutic potential for diseases such as cancer, diabetes, and especially autoimmune diseases. Despite the fact that many small molecule inhibitors have been identified against TNF-α, no orally active drug has been reported yet which demand an urgent need of a small molecule drug against TNF-α. This study focuses on the development of ligand-based selective pharmacophore model to perform virtual screening of plant origin natural product database for the identification of potential inhibitors against TNF-α. The resultant hits, identified as actives were evaluated by molecular docking studies to get insight into their potential binding interaction with the target protein. Based on pharmacophore matching, interacting residues, docking score, more affinity towards TNF-α with diverse scaffolds five compounds were selected for in vitro activity study. Experimental validation led to the identification of three chemically diverse potential compounds with the IC50 32.5 ± 4.5 µM, 6.5 ± 0.8 µM and 27.4 ± 1.7 µM, respectively.

scholarly journals An In Vitro System Recapitulates Chromatin Remodeling at the PHO5 Promoter

1999 ◽  
Vol 19 (4) ◽  
pp. 2817-2827 ◽  
Author(s):  
Elizabeth S. Haswell ◽  
Erin K. O’Shea
Keyword(s):  
Chromatin Remodeling ◽  
Chromatin Structure ◽  
Nuclear Extract ◽  
In Vitro System ◽  
Chromatin Remodeling Complex ◽  
Promoter Dna ◽  
Pho5 Promoter

ABSTRACT The Saccharomyces cerevisiae gene PHO5 is an excellent system with which to study regulated changes in chromatin structure. The PHO5 promoter is packaged into four positioned nucleosomes under repressing conditions; upon induction, the structure of these nucleosomes is altered such that the promoter DNA becomes accessible to nucleases. We report here the development and characterization of an in vitro system in which partially purified PHO5 minichromosomes undergo promoter chromatin remodeling. Several hallmarks of thePHO5 chromatin transition in vivo were reproduced in this system. Chromatin remodeling of PHO5minichromosomes required the transcription factors Pho4 and Pho2, was localized to the promoter region of PHO5, and was independent of the chromatin-remodeling complex Swi-Snf. In vitro chromatin remodeling also required the addition of fractionated nuclear extract and hydrolyzable ATP. This in vitro system should serve as a useful tool for identifying the components required for this reaction and for elucidating the mechanism by which the PHO5promoter chromatin structure is changed.

scholarly journals DNA damage-free iPS cells exhibit potential to yield competent cardiomyocytes

2020 ◽  
Vol 318 (4) ◽  
pp. H801-H815
Author(s):  
Jessica M. Miller ◽  
Nikhil M. Mardhekar ◽  
Danielle Pretorius ◽  
Prasanna Krishnamurthy ◽  
Namakkal Soorappan Rajasekaran ◽  
...  
Keyword(s):  
Dna Damage ◽  
Ion Channel ◽  
Small Molecule ◽  
Therapeutic Potential ◽  
Molecular Signatures ◽  
Intact Cells ◽  
Physiological Functions ◽  
Injured Myocardium ◽  
Free Cells

DNA damage accrued in induced pluripotent stem cell (iPSC)-derived cardiomyocytes during in vitro culture practices lessens their therapeutic potential. We determined whether DNA-damage-free iPSCs (DdF-iPSCs) can be selected using stabilization of p53, a transcription factor that promotes apoptosis in DNA-damaged cells, and differentiated them into functionally competent DdF cardiomyocytes (DdF-CMs). p53 was activated using Nutlin-3a in iPSCs to selectively kill the DNA-damaged cells, and the stable DdF cells were cultured further and differentiated into CMs. Both DdF-iPSCs and DdF-CMs were then characterized. We observed a significant decrease in the expression of reactive oxygen species and DNA damage in DdF-iPSCs compared with control (Ctrl) iPSCs. Next-generation RNA sequencing and Ingenuity Pathway Analysis revealed improved molecular, cellular, and physiological functions in DdF-iPSCs. The differentiated DdF-CMs had a compact beating frequency between 40 and 60 beats/min accompanied by increased cell surface area. Additionally, DdF-CMs were able to retain the improved molecular, cellular, and physiological functions after differentiation from iPSCs, and, interestingly, cardiac development network was prominent compared with Ctrl-CMs. Enhanced expression of various ion channel transcripts in DdF-CMs implies DdF-CMs are of ventricular CMs and mature compared with their counterparts. Our results indicated that DdF-iPSCs could be selected through p53 stabilization using a small-molecule inhibitor and differentiated into ventricular DdF-CMs with fine-tuned molecular signatures. These iPSC-derived DdF-CMs show immense clinical potential in repairing injured myocardium. NEW & NOTEWORTHY Culture-stress-induced DNA damage in stem cells lessens their performance. A robust small-molecule-based approach, by stabilizing/activating p53, to select functionally competent DNA-damage-free cells from a heterogeneous population of cells is demonstrated. This protocol can be adopted by clinics to select DNA-damage-free cells before transplanting them to the host myocardium. The intact DNA-damage-free cells exhibited with fine-tuned molecular signatures and improved cellular functions. DNA-damage-free cardiomyocytes compared with control expressed superior cardiomyocyte functional properties, including, but not limited to, enhanced ion channel signatures. These DNA-intact cells would better engraft, survive, and, importantly, improve the cardiac function of the injured myocardium.

scholarly journals BAF60a Mediates Critical Interactions between Nuclear Receptors and the BRG1 Chromatin-Remodeling Complex for Transactivation

2003 ◽  
Vol 23 (17) ◽  
pp. 6210-6220 ◽  
Author(s):  
Pei-Wen Hsiao ◽  
Christy J. Fryer ◽  
Kevin W. Trotter ◽  
Weidong Wang ◽  
Trevor K. Archer
Keyword(s):  
Nuclear Receptors ◽  
Chromatin Remodeling ◽  
Molecular Mechanisms ◽  
Hormone Receptors ◽  
Nuclear Receptor Coactivators ◽  
Chromatin Remodeling Complex ◽  
Truncation Mutant ◽  
Promoter Recruitment

ABSTRACT Nuclear hormone receptors are ligand-dependent transcriptional regulators that modulate chromatin structure. However, the precise molecular mechanisms by which receptors recruit chromatin-remodeling activity are not fully elucidated. We show that in the absence of its ligand-binding domain, the glucocorticoid receptor (GR) is able to interact with both nuclear receptor coactivators and the BRG1 chromatin-remodeling complex in vivo. Individually, the GR makes direct interactions with BRG1-associated factor 60a (BAF60a) and BAF57, but not with BRG1, BAF155, or BAF170. Further, BAF60a possesses at least two interaction surfaces, one for GR and BRG1 and a second for BAF155 and BAF170. A GR mutant, GR(R488Q), that fails to interact with BAF60a in vitro has reduced chromatin-remodeling activity and reduced transcriptional activity from the promoter assembled as chromatin in vivo. Stable expression of a BAF60a truncation mutant, BAF60a4-140, caused chromatin-specific loss of GR functions in vivo. In the presence of the BAF60a mutant, the GR fails to interact with the BRG1 complex and consequently is also deficient in its ability to activate transcription from chromatin. Thus, in addition to previously identified BAF250, BAF60a may provide another critical and direct link between nuclear receptors and the BRG1 complex that is required for promoter recruitment and subsequent chromatin remodeling.

scholarly journals The Histone H3-H4 Tetramer is a Copper Reductase Enzyme

2018 ◽  
Author(s):  
Narsis Attar ◽  
Oscar A. Campos ◽  
Maria Vogelauer ◽  
Chen Cheng ◽  
Yong Xue ◽  
...  
Keyword(s):  
Gene Expression ◽  
Active Site ◽  
Histone H3 ◽  
Cellular Processes ◽  
Great Oxidation Event ◽  
Altered Gene Expression ◽  
Enzymatic Function ◽  
Putative Active Site ◽  
Altered Gene

AbstractAncestral histones were present in organisms with small genomes, no nucleus, and little evidence for epigenetic regulation, suggesting histones may have additional older functions. We report that the histone H3-H4 tetramer is an enzyme that catalyzes the reduction of Cu2+ to Cu1+ when assembled in vitro from recombinant histones. Mutations of residues in the putative active site at the interface of the apposing H3 proteins alter the enzymatic activity and cellular processes such as Sod1 function or mitochondrial respiration that depend on availability of reduced copper. These effects are not due to altered gene expression or copper abundance but are consistent with decreased levels of cuprous ions. We propose that the H3-H4 tetramer is an oxidoreductase that provides biousable copper for cellular and mitochondrial chemistry. As the emergence of eukaryotes coincided with the Great Oxidation Event and decreased biousability of metals, the histone enzymatic function may have facilitated eukaryogenesis.

199 IN VITRO-DEVELOPED BOVINE BLASTOCYSTS ARE MARKED WITH ABERRANT HYPER- AND HYPO-METHYLATED GENOMIC REGIONS

2015 ◽  
Vol 27 (1) ◽  
pp. 190
Author(s):  
D. Salilew-Wondim ◽  
M. Hoelker ◽  
U. Besenfelder ◽  
V. Havlicek ◽  
F. Rings ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Expression Patterns ◽  
Proximal Promoter ◽  
Altered Gene Expression ◽  
Genome Wide ◽  
Altered Gene ◽  
Genomic Regions

Most often, in vitro produced embryos display poor quality and altered gene expression patterns compared to their in vivo counterparts. Aberrant DNA methylation occurring during in vitro embryo development is believed to be one of the multifaceted factors which may cause altered gene expression and poor embryo quality. Here, we investigated the genome-wide DNA methylation patterns of in vitro derived embryos using the recently developed Bovine EmbryoGENE Methylation Platform (BEGMP) array (Shojaei Saadi et al. BMC Genomics 2014 15, 451. doi: 10.1186/1471-2164-15-451) to unravel the aberrantly methylated genomic region in in vitro developed embryos. For this, in vitro and in vivo produced blastocysts were produced and used for genome-wide DNA methylation analysis. In vitro blastocysts were produced from oocytes retrieved from ovaries collected from the local abattoir and matured, fertilized, and cultured in vitro using SOF media. The in vivo blastocysts were produced by superovulation and AI of Simmental heifers followed by uterine flushing. Genomic DNA (gDNA) was then isolated from four replicates (each 10 blastocysts) of in vivo and in vitro derived blastocysts using Allprep DNA/RNA micro kit (Qiagen, Valencia, CA, USA) and the gDNA was then fragmented using the MseI enzyme. Following this, MseLig21 and MseLig were ligated to the MseI-digested genomic fragments in the presence of Ligase enzyme. Methyl-sensitive enzymes, HpaII, AciI, and Hinp1I, were used to cleave unmethlayted genomic regions within the MseI-MseI region of the fragmented DNA. The gDNA was subjected to two rounds of ligation-mediated polymerase chain reaction (LM-PCR) amplification. After removal of the adapters, the amplified gDNA samples from in vivo or in vitro groups were labelled either Cy-3 or Cy-5 dyes in dye-swap design using ULS Fluorescent gDNA labelling kit (Kreatech Biotechnology BV, Amsterdam, The Netherlands). Hybridization was performed for 40 h at 65°C. Slides were scanned using Agilent's High-Resolution C Scanner (Agilent Technologies Inc., Santa Clara, CA, USA) and features were extracted with Agilent's Feature Extraction software (Agilent Technologies Inc.). The results have shown that from a total of 414 566 probes harboured by the BEGMP array, 248 453 and 253 147 probes were detected in in vitro and in vivo derived blastocysts, respectively. Data analysis using the linear modelling for microarray (LIMMA) package and R software (The R Project for Statistical Computing, Vienna, Austria) revealed a total of 3434 differentially methylated regions (DMRs; Fold change ≥1.5, P-value <0.05), of which 42 and 58% were hyper- and hypo-methylated, respectively, in in vitro derived blastocysts compared to their in vivo counterparts. The DMRs were found to be localised in the intronic, exonic, promoter, proximal promoter, and distal promoter, and some of the probes did not have nearby genes. In addition, 10.8% of the DMRs were found to be stretched in short, long, or intermediate CpG islands. Thus, this study demonstrated genome-wide dysregulation in the epigenome landscape of in vitro-derived embryos by the time they reach to the blastocysts stage.

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