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|Presentation||Contains all necessary reagents to perform 22 individual chromatin immunoprecipitation (ChIP) reactions. Supplied buffers are sufficient to generate chromatin from up to five 15 cm plates of cultured cells, each plate providing up to 10 chromatin preparations (varies with cell and assay type).|
|Application||Contains all necessary reagents to perform 22 individual chromatin immunoprecipitation (ChIP) reactions using inexpensive protein A agarose beads.|
|Safety Information according to GHS|
|Storage and Shipping Information|
|Material Size||1 kit|
|Material Package||Kit capacity: 22 Assays|
Chromatin Immunoprecipitation (ChIP) Assay Kit SDS
|Reference overview||Application||Species||Pub Med ID|
|HDAC1 and HDAC3 underlie dynamic H3K9 acetylation during embryonic neurogenesis and in schizophrenia-like animals.|
Večeřa, J; Bártová, E; Krejčí, J; Legartová, S; Komůrková, D; Rudá-Kučerová, J; Štark, T; Dražanová, E; Kašpárek, T; Šulcová, A; Dekker, FJ; Szymanski, W; Seiser, C; Weitzer, G; Mechoulam, R; Micale, V; Kozubek, S
J Cell Physiol 233 530-548 2018
Although histone acetylation is one of the most widely studied epigenetic modifications, there is still a lack of information regarding how the acetylome is regulated during brain development and pathophysiological processes. We demonstrate that the embryonic brain (E15) is characterized by an increase in H3K9 acetylation as well as decreases in the levels of HDAC1 and HDAC3. Moreover, experimental induction of H3K9 hyperacetylation led to the overexpression of NCAM in the embryonic cortex and depletion of Sox2 in the subventricular ependyma, which mimicked the differentiation processes. Inducing differentiation in HDAC1-deficient mouse ESCs resulted in early H3K9 deacetylation, Sox2 downregulation, and enhanced astrogliogenesis, whereas neuro-differentiation was almost suppressed. Neuro-differentiation of (wt) ESCs was characterized by H3K9 hyperacetylation that was associated with HDAC1 and HDAC3 depletion. Conversely, the hippocampi of schizophrenia-like animals showed H3K9 deacetylation that was regulated by an increase in both HDAC1 and HDAC3. The hippocampi of schizophrenia-like brains that were treated with the cannabinoid receptor-1 inverse antagonist AM251 expressed H3K9ac at the level observed in normal brains. Together, the results indicate that co-regulation of H3K9ac by HDAC1 and HDAC3 is important to both embryonic brain development and neuro-differentiation as well as the pathophysiology of a schizophrenia-like phenotype.
|Differential in Vitro Biological Action, Coregulator Interactions, and Molecular Dynamic Analysis of Bisphenol A (BPA), BPAF, and BPS Ligand-ERα Complexes.|
Li, Y; Perera, L; Coons, LA; Burns, KA; Tyler Ramsey, J; Pelch, KE; Houtman, R; van Beuningen, R; Teng, CT; Korach, KS
Environ Health Perspect 126 017012 2018
Bisphenol A (BPA) is an endocrine-disrupting chemical (EDC) that might be harmful to human health. Recently, there has been widespread usage of bisphenol chemicals (BPs), such as bisphenol AF (BPAF) and bisphenol S (BPS), as replacements for BPA. However, the potential biological actions, toxicity, and the molecular mechanism of these compounds are still poorly understood.Our objective was to examine the estrogenic effects of BPA, BPAF, and BPS and the molecular mechanisms of action in the estrogen receptor alpha (ERα) complex.In vitro cell models were used to compare the estrogenic effects of BPA, BPAF, and BPS to estrogen. Microarray Assay for Real-Time Coregulator-Nuclear receptor Interaction (MARCoNI) analysis was used to identify coregulators of BPA, BPAF, and BPS, and molecular dynamic (MD) simulations were used to determine the compounds binding in the ERα complex.We demonstrated that BPA and BPAF have agonistic activity for both ERα and ERβ, but BPS has ERα-selective specificity. We concluded that coregulators were differentially recruited in the presence of BPA, BPAF, or BPS. Interestingly, BPS recruited more corepressors when compared to BPA and BPAF. From a series of MD analysis, we concluded that BPA, BPAF, and BPS can bind to the ER-ligand-binding domain with differing energetics and conformations. In addition, the binding surface of coregulator interactions on ERα was characterized for the BPA, BPAF, and BPS complexes.These findings further our understanding of the molecular mechanisms of EDCs, such as BPs, in ER-mediated transcriptional activation, biological activity, and their effects on physiological functions in human health. https://doi.org/10.1289/EHP2505.
|Tumor-secreted Pros1 inhibits macrophage M1 polarization to reduce antitumor immune response.|
Ubil, E; Caskey, L; Holtzhausen, A; Hunter, D; Story, C; Earp, HS
J Clin Invest 128 2356-2369 2018
Tyro3, Axl, Mer (TAM) receptor tyrosine kinases reduce inflammatory, innate immune responses. We demonstrate that tumor-secreted protein S (Pros1), a Mer/Tyro3 ligand, decreased macrophage M1 cytokine expression in vitro and in vivo. In contrast, tumor cells with CRISPR-based deletion of Pros1 failed to inhibit M1 polarization. Tumor cell-associated Pros1 action was abrogated in macrophages from Mer- and Tyro3- but not Axl-KO mice. In addition, several other murine and human tumor cell lines suppressed macrophage M1 cytokine expression induced by IFN-γ and LPS. Investigation of the suppressive pathway demonstrated a role for PTP1b complexing with Mer. Substantiating the role of PTP1b, M1 cytokine suppression was also lost in macrophages from PTP1b-KO mice. Mice bearing Pros1-deficient tumors showed increased innate and adaptive immune infiltration, as well as increased median survival. TAM activation can also inhibit TLR-mediated M1 polarization. Treatment with resiquimod, a TLR7/8 agonist, did not improve survival in mice bearing Pros1-secreting tumors but doubled survival for Pros1-deleted tumors. The tumor-derived Pros1 immune suppressive system, like PD-L1, was cytokine responsive, with IFN-γ inducing Pros1 transcription and secretion. Inhibition of Pros1/TAM interaction represents a potential novel strategy to block tumor-derived immune suppression.
|RGC-32 (Response Gene to Complement 32) Deficiency Protects Endothelial Cells From Inflammation and Attenuates Atherosclerosis.|
Cui, XB; Luan, JN; Dong, K; Chen, S; Wang, Y; Watford, WT; Chen, SY
Arterioscler Thromb Vasc Biol 38 e36-e47 2018
The objective of this study is to determine the role and underlying mechanisms of RGC-32 (response gene to complement 32 protein) in atherogenesis.RGC-32 was mainly expressed in endothelial cells of atherosclerotic lesions in both ApoE-/- (apolipoprotein E deficient) mice and human patients. Rgc-32 deficiency (Rgc32-/-) attenuated the high-fat diet-induced and spontaneously developed atherosclerotic lesions in ApoE-/- mice without affecting serum cholesterol concentration. Rgc32-/- seemed to decrease the macrophage content without altering collagen and smooth muscle contents or lesional macrophage proliferation in the lesions. Transplantation of WT (wild type) mouse bone marrow to lethally irradiated Rgc32-/- mice did not alter Rgc32-/--caused reduction of lesion formation and macrophage accumulation, suggesting that RGC-32 in resident vascular cells, but not the macrophages, plays a critical role in the atherogenesis. Of importance, Rgc32-/- decreased the expression of ICAM-1 (intercellular adhesion molecule-1) and VCAM-1 (vascular cell adhesion molecule-1) in endothelial cells both in vivo and in vitro, resulting in a decrease in TNF-α (tumor necrosis factor-α)-induced monocyte-endothelial cell interaction. Mechanistically, RGC-32 mediated the ICAM-1 and VCAM-1 expression, at least partially, through NF (nuclear factor)-κB signaling pathway. RGC-32 directly interacted with NF-κB and facilitated its nuclear translocation and enhanced TNF-α-induced NF-κB binding to ICAM-1 and VCAM-1 promoters.RGC-32 mediates atherogenesis by facilitating monocyte-endothelial cell interaction via the induction of endothelial ICAM-1 and VCAM-1 expression, at least partially, through NF-κB signaling pathway.
|Nuclear IGF-1R interacts with regulatory regions of chromatin to promote RNA polymerase II recruitment and gene expression associated with advanced tumor stage.|
Aleksic, T; Gray, NE; Wu, X; Rieunier, G; Osher, E; Mills, J; Verrill, C; Bryant, RJ; Han, C; Hutchinson, K; Lambert, A; Kumar, R; Hamdy, FC; Weyer-Czernilofsky, U; Sanderson, M; Bogenrieder, T; Taylor, S; Macaulay, VM
Cancer Res 0 2018
Internalization of ligand-activated type 1 IGF receptor (IGF-1R) is followed by recycling to the plasma membrane, degradation or nuclear translocation. Nuclear IGF-1R reportedly associates with clinical response to IGF-1R inhibitory drugs, yet its role in the nucleus is poorly characterized. Here we investigated the significance of nuclear IGF-1R in clinical cancers and cell line models. In prostate cancers, IGF-1R was predominantly membrane-localized in benign glands, while malignant epithelium contained prominent internalized (nuclear/cytoplasmic) IGF-1R, and nuclear IGF-1R associated significantly with advanced tumor stage. Using ChIP-seq to assess global chromatin occupancy, we identified IGF-1R binding sites at or near transcription start sites of genes including JUN and FAM21, most sites coinciding with occupancy by RNA polymerase II (RNAPol2) and histone marks of active enhancers/promoters. IGF-1R was inducibly recruited to chromatin, directly binding DNA and interacting with RNAPol2 to upregulate expression of JUN and FAM21, shown to mediate tumor cell survival and IGF-induced migration. IGF-1 also enriched RNAPol2 on promoters containing IGF-1R binding sites. These functions were inhibited by IGF-1/2 neutralizing antibody xentuzumab (BI 836845), or by blocking receptor internalization. We detected nuclear IGF-1R on JUN and FAM21 promoters in fresh prostate cancers that contained abundant nuclear IGF-1R, with evidence of correlation between nuclear IGF-1R content and JUN expression in malignant prostatic epithelium. Taken together, these data reveal previously unrecognized molecular mechanisms through which IGFs promote tumorigenesis, with implications for therapeutic evaluation of anti-IGF drugs.
|miR-4725-3p targeting Stim1 signaling is involved in xanthohumol inhibition of glioma cell invasion.|
Ho, KH; Chang, CK; Chen, PH; Wang, YJ; Chang, WC; Chen, KC
J Neurochem 0 2018
Glioblastoma multiforme (GBM) is the most common brain tumor in adults. Due to its highly invasive nature, it is not easy to treat, resulting in high mortality rates. Stromal interacting molecule 1 (Stim1) plays important roles in regulating store-operated Ca2+ entry (SOCE), and controls invasion by cancer cells. However, the mechanisms and functions of Stim1 in glioma progression are still unclear. In this study, we investigated the effects of targeting Stim1 expression on glioma cell invasion. By analyzing profiles of GBM patients from RNA-sequencing data in The Cancer Genome Atlas (TCGA), higher expression levels of STIM1 were correlated with the poor survival. Furthermore, signaling pathways associated with tumor malignancy, including the epithelial-to-mesenchymal transition (EMT), were activated in patients with high STIM1 expression according to gene set enrichment analyses. Higher Stim1 levels were found in glioma cells compared to human astrocytes, and these higher levels enhanced glioma cell invasion. Xanthohumol (XN), a prenylated flavonoid extracted from the hop plant Humulus lupulus L. (Cannabaceae), significantly reduced cell invasion through inhibiting Stim1 expression. From an micro(mi)RNA array analysis, miR-4725-3p was upregulated by XN treatment. Overexpression of miR-4725-3p inhibited glioma cell invasion via directly targeting the 3'-untranslated region of STIM1. The extracellular signal-regulated kinase/c-Fos pathway was also validated to participate in XN-upregulated miR-4725-3p expression according to promoter and chromatin immunoprecipitation assays. These results emphasize that miR-4725-3p-inhibited STIM1 signaling is involved in XN-attenuated glioma cell invasion. These findings may provide insights into novel therapeutic strategies for future glioblastoma therapy and drug development. This article is protected by copyright. All rights reserved.
|Tissue-specific CTCF-cohesin-mediated chromatin architecture delimits enhancer interactions and function in vivo.|
Hanssen, LLP; Kassouf, MT; Oudelaar, AM; Biggs, D; Preece, C; Downes, DJ; Gosden, M; Sharpe, JA; Sloane-Stanley, JA; Hughes, JR; Davies, B; Higgs, DR
Nat Cell Biol 19 952-961 2017
The genome is organized via CTCF-cohesin-binding sites, which partition chromosomes into 1-5 megabase (Mb) topologically associated domains (TADs), and further into smaller sub-domains (sub-TADs). Here we examined in vivo an ∼80 kb sub-TAD, containing the mouse α-globin gene cluster, lying within a ∼1 Mb TAD. We find that the sub-TAD is flanked by predominantly convergent CTCF-cohesin sites that are ubiquitously bound by CTCF but only interact during erythropoiesis, defining a self-interacting erythroid compartment. Whereas the α-globin regulatory elements normally act solely on promoters downstream of the enhancers, removal of a conserved upstream CTCF-cohesin boundary extends the sub-TAD to adjacent upstream CTCF-cohesin-binding sites. The α-globin enhancers now interact with the flanking chromatin, upregulating expression of genes within this extended sub-TAD. Rather than acting solely as a barrier to chromatin modification, CTCF-cohesin boundaries in this sub-TAD delimit the region of chromatin to which enhancers have access and within which they interact with receptive promoters.
|The chromatin remodelling factor ATRX suppresses R-loops in transcribed telomeric repeats.|
Nguyen, DT; Voon, HPJ; Xella, B; Scott, C; Clynes, D; Babbs, C; Ayyub, H; Kerry, J; Sharpe, JA; Sloane-Stanley, JA; Butler, S; Fisher, CA; Gray, NE; Jenuwein, T; Higgs, DR; Gibbons, RJ
EMBO Rep 18 914-928 2017
ATRX is a chromatin remodelling factor found at a wide range of tandemly repeated sequences including telomeres (TTAGGG)n ATRX mutations are found in nearly all tumours that maintain their telomeres via the alternative lengthening of telomere (ALT) pathway, and ATRX is known to suppress this pathway. Here, we show that recruitment of ATRX to telomeric repeats depends on repeat number, orientation and, critically, on repeat transcription. Importantly, the transcribed telomeric repeats form RNA-DNA hybrids (R-loops) whose abundance correlates with the recruitment of ATRX Here, we show loss of ATRX is also associated with increased R-loop formation. Our data suggest that the presence of ATRX at telomeres may have a central role in suppressing deleterious DNA secondary structures that form at transcribed telomeric repeats, and this may account for the increased DNA damage, stalling of replication and homology-directed repair previously observed upon loss of ATRX function.
|DNA methylation of intragenic CpG islands depends on their transcriptional activity during differentiation and disease.|
Jeziorska, DM; Murray, RJS; De Gobbi, M; Gaentzsch, R; Garrick, D; Ayyub, H; Chen, T; Li, E; Telenius, J; Lynch, M; Graham, B; Smith, AJH; Lund, JN; Hughes, JR; Higgs, DR; Tufarelli, C
Proc Natl Acad Sci U S A 114 E7526-E7535 2017
The human genome contains ∼30,000 CpG islands (CGIs). While CGIs associated with promoters nearly always remain unmethylated, many of the ∼9,000 CGIs lying within gene bodies become methylated during development and differentiation. Both promoter and intragenic CGIs may also become abnormally methylated as a result of genome rearrangements and in malignancy. The epigenetic mechanisms by which some CGIs become methylated but others, in the same cell, remain unmethylated in these situations are poorly understood. Analyzing specific loci and using a genome-wide analysis, we show that transcription running across CGIs, associated with specific chromatin modifications, is required for DNA methyltransferase 3B (DNMT3B)-mediated DNA methylation of many naturally occurring intragenic CGIs. Importantly, we also show that a subgroup of intragenic CGIs is not sensitive to this process of transcription-mediated methylation and that this correlates with their individual intrinsic capacity to initiate transcription in vivo. We propose a general model of how transcription could act as a primary determinant of the patterns of CGI methylation in normal development and differentiation, and in human disease.
|Transcription factor NF-kappa B represses ANT1 transcription and leads to mitochondrial dysfunctions.|
Zhang, C; Jiang, H; Wang, P; Liu, H; Sun, X
Sci Rep 7 44708 2017
Mitochondria are intracellular organelles involved in cell survival and death, and dysfunctions of mitochondria are related to neurodegenerative diseases. As the most abundant protein in the mitochondrial inner membrane, adenine nucleotide translocator 1 (ANT1) plays a critical role in mitochondrial function, including the exchange of adenosine triphosphate/adenosine diphosphate (ATP/ADP) in mitochondria, basal proton leak and mitochondrial permeability transition pore (mPTP). Here, we show that ANT1 transcription is regulated by transcription factor NF-kappa B (NF-κB). NF-κB is bound to two NF-κB responsive elements (NREs) located at +1 to +20 bp and +41 to +61 bp in the ANT1 promoter. An NF-κB signalling stimulator, tumour necrosis factor alpha (TNFα), suppresses ANT1 mRNA and protein expression. Activation of NF-κB by TNFα impairs ATP/ADP exchange and decreases ATP production in mitochondria. Activation of NF-κB by TNFα decreases calcium induced mPTP opening, elevates mitochondrial potential and increases reactive oxygen species (ROS) production in both T98G human glioblastoma cells and rat cortical neurons. These results demonstrate that NF-κB signalling may repress ANT1 gene transcription and impair mitochondrial functions.
|Why is chromatin important?||Any process that uses DNA as a template (replication, transcription, mitosis, etc.) needs to contend with its organization into chromatin (the protein-DNA complex that is present within the nucleus of eukaryotic cells).|
|How would you recommend eluting Antibody-protein-DNA complexes from agarose (or sepharose) in order to perform a Re-ChIP experiment?||The complex is removed with the elution buffer that you find in the ChIP assay kit. For a re-CHIP, it might make sense to add protease inhibitors to the IP wash buffers and the elution buffer and the second set of dilution buffers. Make sure everything stays cold so that the proteins aren't degraded during the collection of the first complex or during the second IP.|
|Why do you have to shear the DNA down less than 1000 base pairs (to about three nucleosomes ~400-500bp)?||To insure good resolution for ChIP. If your average fragment size is greater than 1000 bp, you could be pulling down DNA that contains your target sequence for PCR but the protein of interest may be over 700 nucleotides distant from your target.|
|Is there ever a time when I do not need to cross-link Histones?||In native ChIP, Histone H3 and Histone H4 do not need to be crosslinked as they are very tightly associated. Histone H2A and Histone H2B are not as tightly associated, but will still work in native ChIP.|
|What were your conditions for PCR?||Please see the manual for The EZ ChIP Kit (Catalog #17-371) for more information.|
|If I wanted to quantitate my immunoprecipitated DNA, how would I do so?||DNA purified from ChIP experiments can be quantitated by PCR, providing the amplifying oligos meet specific criteria. Oligos should be 24 mers, with a GC content of 50% (+/- 4) and a Tm of 60.0C (+/- 2.0). You must be certain that the PCR reactions are within the linear range of amplification. Generally it takes time to achieve this. Too much input DNA will affect your results, so set up several tubes for each experiment to optimize the input DNA. Generally, this is about 1/25th to 1/100th for yeast, approximately 1/10 for mammalian cells, but depends on the amount of antibody and input chromatin.
Also, do not use more than 20 cycles, making sure that dNTP's always remain in excess. Also, include each reaction a control primer (to compare your experimental band against-make sure the sizes are sufficiently different to allow proper separation-75 base pairs is usually OK) set to a region of the genome that should not change throughout your experimental conditions. Also PCR from purified input DNA (no ChIP) and include no antibody control PCR's as well. PCR products should be no more than 500 base pairs and should span the area of interest (where you think you will see changes in acetylation or methylation of histones). All PCR products should be run on 7-8% acrylamide gels and stained with SYBR Green 1 (Molecular Probes) at a dilution of 1:10,000 (in 1X Tris-borate-EDTA buffer, pH 7.5) for 30 minutes-no destaining is required.
Quantitation is carried out subsequent to scanning of the gel on a Molecular Dynamics Storm 840 or 860 in Blue fluorescence mode with PMT voltage at 900 with ImageQuant software. This has distinct advantages over ethidium bromide staining. SYBR Green is much more sensitive, and illumination of ethidium stained gels can vary across the gel based on the quality of UV bulbs in your in your light box. For further info, see Strahl-Bolsinger et al. (1997) Genes Dev. 11: 83-93. A radioactive quantitation m
|I am not getting amplification with input DNA. What did I do wrong?||Your input DNA sample should be taken just prior to adding the antibody. It is considered the starting material. If you are not seeing amplification with your input DNA, either you have not successfully reversed the cross links or the PCR is not working for reasons other than the kit.|
|Do you have any tips for sonication?||Keep cells on ice throughout the procedure - even during sonication. Be sure that you don't sonicate for to long (more than 30 seconds could cause sample overheating and denaturation).|
|Why is more DNA is precipitated in my no-antibody control than for my test sample?||To eliminate banding in your negative controls you can do several things:
A) Pre-clear the 2ml diluted cell pellet suspension with 80 microliters of Salmon Sperm DNA/Protein A Agarose-50% Slurry for 30 minutes at 4ºC with agitation. You could try to preclear the lysate longer or with more clearings.
B) Titrate your input DNA, to see when the bands in the NFA disappear.
C) Use an alternative lysis procedure: Resuspend cell pellet in 200 microliters of 5mM Pipes pH 8.0, 85mM KCl, 0.5% NP40 containing protease inhibitors. Place on ice for 10 minutes. Pellet by centrifugation (5 minutes at 5000 rpm). Resuspend pellet in 200 microliters of 1% SDS, 10mM EDTA, 50mM Tris-HCl, pH 8.1 containing protease inhibitors. Incubate on ice for 10 minutes.
D) Block the Salmon Sperm DNA Agarose prior to use in 1-5% BSA and Chip dilution buffer (mix at room temperature for 30 minutes). After incubation, spin the agarose and remove the 1% BSA/ChIP assay buffer supernatant. Wash once in ChIP assay buffer and continue.
|What is 'Input DNA', and why no 'Output DNA'?||Input DNA is DNA obtained from chromatin that has been cross-link reversed similar to your samples. It is a control for PCR effectiveness. Output DNA is the DNA from each of your ChIP experiments.|