Similar Datasets
Project description:Understanding factors that drive development and function of the sinoatrial node (SAN) is crucial to development of potential therapies for sinus arrhythmias, including potential generation of biological pacemakers. Here, we identify a key cell autonomous role for the LIM homeodomain transcription factor ISL1 for survival, proliferation and function of pacemaker cells throughout development. Chromatin immunoprecipitation assays performed utilizing antibody to ISL1 in chromatin extracts from FACS purified SAN cells demonstrated that ISL1 directly binds genomic regions within several genes critical for normal pacemaker function, including subunits of the L-type calcium channel, Ank2, and Tbx3. Other genes implicated in abnormal heart rhythm in humans were also direct downstream targets of ISL1 in SAN cells. Our studies represent the first in vivo ChIP-seq studies for SAN cells which provide a basis for further exploration of factors critical to SAN formation and function and highlight the potential for utilization of ISL1 in combination with other SAN transcription factors for generating pacemaker cells for therapy or drug screening purposes. ISL1 ChIP-seq profiling was performed in Hcn4-H2BGFP SAN cells purified from neonatal hearts.
2015-07-23 | E-GEOD-68974 | biostudies-arrayexpress
Project description:Visceral fat (VF) and subcutaneous fat (SF) are developmentally different tissues with different gene expression. Islet-1 (ISL1), a LIM-homeobox transcription factor with important developmental and regulatory function in islet, neural, and cardiac tissue, is virtually absent in SF but substantially expressed in the stromovascular [preadipocyte containing] fraction of VF; expression correlates negatively with adiposity in rodents and man. ISL1 expression is transiently increased in 3T3-L1 preadipocytes during early differentiation, suggesting a functional role. To examine the role of ISL1 in adipogenesis, we tested whether retroviral overexpression of ISL1 in 3T3-L1 preadipocytes affected their ability to differentiate into mature adipocytes. Terminal differentiation was assessed by Oil Red O [lipid droplet] staining and by immunoblot detection of adipocyte marker proteins, including aP2 and GLUT4. ISL1 significantly inhibited lipid droplet formation, reduced lipid accumulation (about 80% inhibition, p<0.05), and substantially inhibited aP2 and GLUT4 expression. ISL1 did not inhibit expression of C/EBPb and C/EBPd after induction of differentiation, but reduced PPARg and C/EBPa by >50% at both mRNA and protein level. In addition, the PPARg agonist, rosiglitazone, substantially rescued ISL1 inhibited adipogenesis in the absence of exogenous PPARg, and fully rescued in the presence of exogenous PPARg. In summary, ISL1 overexpression inhibited fat droplet formation, lipid accumulation, and adipocyte-specific gene expression; there was accompanying inhibition of C/EBPa, PPARg and downstream gene expression. We conclude that ISL1 overexpression inhibited adipocyte differentiation by inhibition of PPARg regulated gene expression. As abdominal obesity strongly correlates with insulin resistance, and cardiovascular risk, ISL1 up-regulation may impact abdominal obesity and its concomitant metabolic derangements. Total cellular RNA was isolated from 3T3-L1 cells expressing Flag-ISL1 or not at 48 h following treatment with differentiation cocktail. Individual RNA from biological triplicates was used for microarray analysis.
2012-09-05 | E-GEOD-40565 | biostudies-arrayexpress
Project description:We report the high-throughput profiling of ISL1-binding sites in mammalian cells. By obtaining over four billion bases of sequence from chromatin immunoprecipitated DNA, we generated genome-wide ISL1-binding maps of Huh7 cells. This study provides a prediction of regulated genes by the ISL1.
2019-02-01 | GSE77957 | GEO
Project description:We report the high-throughput profiling of ISL1-binding sites in mammalian cells. By obtaining over four billion bases of sequence from chromatin immunoprecipitated DNA, we generated genome-wide ISL1-binding maps of SGC7901 cells. This study provides a prediction of regulated genes by the ISL1.
2019-03-06 | GSE122056 | GEO
Project description:Understanding factors that drive development and function of the sinoatrial node (SAN) is crucial to development of potential therapies for sinus arrhythmias, including potential generation of biological pacemakers. Here, we identify a key cell autonomous role for the LIM homeodomain transcription factor ISL1 for survival, proliferation and function of pacemaker cells throughout development. Analysis of several Isl1 mutant mouse lines, including one in which Isl1 was specifically ablated in SAN (Hcn4- CreERT2;Isl1) revealed an early requirement for Isl1 within SAN for embryonic viability. RNA-seq analyses on FACS purified SAN cells revealed dysregulation of a number of genes critical for SAN function to be downstream of ISL1 in Hcn4-CreERT2;Isl1 mutants, including transcription factors and ion channels. Our studies demonstrated that ISL1 regulated approximately one third of genes that were significantly expressed in SAN, and highlight the potential for utilization of ISL1 in combination with other SAN transcription factors for generating pacemaker cells for therapy or drug screening purposes. Results also suggest Isl1 as a candidate gene for sick sinus syndrome. RNA-seq analyses were performed on samples from Hcn4-CreERT2;Isl1 mutant and control SANs
2015-07-24 | E-GEOD-69097 | biostudies-arrayexpress
Project description:The LIM-homeobox transcription factor islet-1 (ISL1) has been proposed as a marker of cardiovascular progenitor cells. This study investigated whether forced expression of ISL1 in human mesenchymal stem cells (hMSCs) improves myocardial infarction (MI) treatment outcomes. The lentiviral vector EF1α-ISL1 was constructed using the Multisite Gateway System, and used to transduce hMSCs.
2018-01-01 | GSE107923 | GEO
Project description:The goal of this study is to analyze the transcriptome profiling (RNA-seq) after ISL1 knockdown. The objective of this study is to elucidate the mechanisms of ISL1 in gastric carcinogenesis, RNA-Seq is performed in BGC823 cells with stable ISL1 knockdown. Comparison and identification of the candidate genes based on the intersection of RNA-seq showed that upregulated and downregulated genes had ISL1-bound regions.
2021-03-24 | GSE147006 | GEO
Project description:ISL1 is expressed in cardiac progenitor cells and plays critical roles in cardiac lineage differentiation and heart development. Cardiac progenitor cells hold great potential for clinical and translational applications. However the mechanisms underlying ISL1 function in cardiac progenitor cells have not been fully elucidated. Here we uncover a hierarchical role of ISL1 in cardiac progenitor cells, showing that ISL1 directly regulates hundreds of potential downstream targets that are implicated in cardiac differentiation, through an epigenetic mechanism. Specifically, ISL1 promotes the demethylation of tri-methylation of histone H3K27 (H3K27me3) at the enhancers of key downstream target genes, including Myocd and Mef2c, which are core cardiac transcription factors. ISL1 physically interacts with JMJD3, a H3K27me3 demethylase, and conditional depletion of JMJD3 leads to impaired cardiac progenitor cell differentiation, phenocopying that of ISL1 depletion. Interestingly, ISL1 is not only responsible for the recruitment of JMJD3 to specific target loci during cardiac progenitor differentiation, but also modulates its demethylase activity. In conclusion, ISL1 and JMJD3 partners to alter the cardiac epigenome, instructing gene expression changes that drive cardiac differentiation.
2016-04-25 | GSE79700 | GEO
Project description:ISL1 is expressed in cardiac progenitor cells and plays critical roles in cardiac lineage differentiation and heart development. Cardiac progenitor cells hold great potential for clinical and translational applications. However the mechanisms underlying ISL1 function in cardiac progenitor cells have not been fully elucidated. Here we uncover a hierarchical role of ISL1 in cardiac progenitor cells, showing that ISL1 directly regulates hundreds of potential downstream targets that are implicated in cardiac differentiation, through an epigenetic mechanism. Specifically, ISL1 promotes the demethylation of tri-methylation of histone H3K27 (H3K27me3) at the enhancers of key downstream target genes, including Myocd and Mef2c, which are core cardiac transcription factors. ISL1 physically interacts with JMJD3, a H3K27me3 demethylase, and conditional depletion of JMJD3 leads to impaired cardiac progenitor cell differentiation, phenocopying that of ISL1 depletion. Interestingly, ISL1 is not only responsible for the recruitment of JMJD3 to specific target loci during cardiac progenitor differentiation, but also modulates its demethylase activity. In conclusion, ISL1 and JMJD3 partners to alter the cardiac epigenome, instructing gene expression changes that drive cardiac differentiation.
2016-04-25 | GSE79699 | GEO