NCBI Logo
GEO Logo
   NCBI > GEO > Accession DisplayHelp Not logged in | LoginHelp
GEO help: Mouse over screen elements for information.
          Go
Sample GSM3978645 Query DataSets for GSM3978645
Status Public on Feb 24, 2023
Title mm_islets_dbdb_H3K27Ac_ChIPseq_B
Sample type SRA
 
Source name Pancreatic islets
Organism Mus musculus
Characteristics chip antibody: H3K27ac (Active Motif 39133)
treatment/condition/replicate: db/db recently hyperglycemic (250 mg/dL) Rep 2
Treatment protocol Human islet mRNA-seq: Upon receipt, human islets were stained with dithizone and positively-staining material was hand-picked using a dissection microscope. Islets were allowed to recover 18-48 hours in complete media (CMRL 1066 with 13 mM glucose, 10% FBS, 2 mM L-glutamine, 100 U/mL Pen/Strep, 1 mM sodium pyruvate, 10 mM HEPES, and 0.25 mg/mL amphoterecin B) at 37°C with 5% CO2 prior to treatments. For LSD1 inhibition studies, 2 mM tranylcypromine (Sigma) was included in the culture media for 24 hours prior to analysis.
Extracted molecule genomic DNA
Extraction protocol ChIP-seq: Islets were processed for ChIP immediately following isolation (for mouse islets) or shipping (for human islets). Mouse islets were hand-picked twice under a dissecting microscope to minimize acinar cell contamination. Human islets selected for ChIP-seq analysis were of > 90% purity to facilitate analysis of large quantities of islets without the need for dithizone staining. For Lsd1 ChIP, islets were transferred to complete islet media (CMRL 1066 with 13 mM glucose, 10% FBS, 2 mM L-glutamine, 100 U/mL Pen/Strep, 1 mM sodium pyruvate, 10 mM HEPES, and 0.25 mg/mL amphoterecin B) containing 1.11% formaldehyde and fixed on a rocker for 15 minutes. The reaction was quenched for 5 minutes in 0.125 M glycine. Cells were then washed in DPBS containing 0.5% NP-40 then once again in DPBS supplemented with 0.5% NP-40 and 1 mM PMSF. Islets were lysed and ChIP was performed using the ChIP-IT High Sensitivity Kit (Active Motif) with 30 μg of sheared chromatin and 4 μg anti-Lsd1 antibody (ab17721, Abcam). For histone ChIP, islets were washed once in Hanks Balanced Salt Solution (Hyclone) and then fixed for 10 min in DPBS containing 1.11% formaldehyde. Cross-linking was quenched as before, then islets were lysed by passage through a 25 gauge needle in lysis buffer (10 mM Tris-Hcl, pH 8.0, 10 mM NaCl, 3 mM MgCl2, 1% NP-40, 1% SDS, 0.5% sodium deoxycholate). ChIP was then performed as described above using 10 or 30 μg of sheared chromatin and 4 μg of anti-H3K4me1 (ab8895, Abcam) or anti-H3K27ac (39133, Active Motif) antibodies, respectively. mRNA-seq: Human islets were first treated as described under the "treatment protocol" section above, while mouse islets were processed for RNA purification immediately following isolation. Following mouse islet isolation, islets were hand-picked twice under a dissecting microscope to minimize acinar contamination, and were then pooled from at least 2 animals per biologicla replicate. For all mRNA-seq experiments, RNA was isolated using the RNeasy Micro kit (QIAGEN) according to the manufacturer’s instructions.
ChIP-seq ibraries were constructed from purified DNA using the KAPA DNA Library Preparation Kit for Illumina (Kapa Biosystems). Input libraries were prepared from each experimental replicate using 10 ng of DNA purified immediately following shearing. Libraries were sequenced using HiSeq 4000 (Illumina). mRNA-seq libraries were prepared from 35 ng of total RNA using the TruSeq Stranded mRNA Library Prep Kit (Illumina) with the exception of db/db mouse islets and their respective controls, from which libraries were generated with 1 μg of total RNA as described in (Xie, R. et al. Dynamic chromatin remodeling mediated by polycomb proteins orchestrates pancreatic differentiation of human embryonic stem cells. Cell Stem Cell 12, 224-237, 2013).
 
Library strategy ChIP-Seq
Library source genomic
Library selection ChIP
Instrument model Illumina HiSeq 4000
 
Description dbdb_H3K27ac.ucsc.bedGraph.gz
Data processing ChIP-seq: Bowtie2 v 2.2.7 was used for mapping of ChIP-seq data to the human reference genome hg19 with a seed length of 33 bp and a maximum of 2 mismatches allowed in the seed region, discarding reads aligning to multiple sites. Duplicate reads were removed using SAMtools.
ChIP-seq: Two biological replicates were used for ChIP-seq data analysis, and replicates were merged prior to analysis
ChIP-seq: Peak calling was performed using the findPeaks program of the HOMER suite of bioinformatics tools with the options -style histone, -P 0.0000001 for H3K27ac or -style factor for Lsd1 (with default P-value cutoff of P < 0.0001) with replicate-matched ChIP-seq input used as background.
mRNA-seq: mRNA-seq reads were mapped to NCBI37/mm9 (mouse) or GRCh37/hg19 (human) genomes by STAR (STAR-STAR_2.4.0f1, --outSAMstrandField intronMotif --outFilterMultimapNmax 1 --runThreadN 5), excluding reads mapping to multiple loci. Reads with exact matches were used to determine RPKM by Cufflinks (cufflinks v2.2.1,-p 6 -G $gtf_file --max-bundle-frags 1000000000).
mRNA-seq: Cuffdiff was used to assess expression differences for all pairwise comparisons, with P < 0.01 considered significant. Genes with mean RPKM > 1 in at least one experimental group were considered to be expressed, and all non-expressed genes were excluded from downstream analyses.
Genome_build: mm9 or hg19
Supplementary_files_format_and_content: ChIP-seq: Bedgraph files were generated from merged replicates. Peak files are provided in BED format. mRNA-seq: Cuffdiff output comparing experimental groups
 
Submission date Jul 25, 2019
Last update date Feb 24, 2023
Contact name Matthew Wortham
E-mail(s) mwortham@ucsd.edu
Phone 8582460588
Organization name University of California, San Diego
Lab Maike Sander
Street address 2880 Torrey Pines Scenic Drive, Sanford Consortium for Regenerative Medicine, Room 3102
City La Jolla
State/province CA
ZIP/Postal code 92037
Country USA
 
Platform ID GPL21103
Series (1)
GSE134901 Nutrient regulation of the islet epigenome controls adaptive insulin secretion
Relations
BioSample SAMN12367481
SRA SRX6595728

Supplementary data files not provided
SRA Run SelectorHelp
Raw data are available in SRA
Processed data are available on Series record

| NLM | NIH | GEO Help | Disclaimer | Accessibility |
NCBI Home NCBI Search NCBI SiteMap