Project description:Exosomes carry cell-specific proteins or mRNAs/miRNAs that mediate the functional effect of exosomes. To investigate whether miRNAs within GATA4-Exo are important for their cardioprotective effects, we utilized an unbiased approach by performing an exosomal miRNA array analysis. Total RNA was extracted from CDCs-Exo by using a Qiagen miRNeasy Mini Kit. Global expression patterns of miRNAs were then examined by using Affymetrix GeneChip miRNA 4.0 arrays.Expression data were generated by using Affymetrix Expression Console software and normalized according to the MAS5 method. The RVM t test was applied to filter the differentially expressed genes for the control and experimental groups. Differentially expressed genes were defined based on a P-value threshold and fold-change analysis.
Project description:Regulatory proteins associate with the genome either by directly binding cognate DNA motifs or via protein-protein interactions with other regulators. Each genomic recruitment mechanism may be associated with distinct motifs, and may also result in distinct characteristic patterns in high-resolution protein-DNA binding assays. For example, the ChIP-exo protocol precisely characterizes protein-DNA crosslinking patterns by combining chromatin immunoprecipitation (ChIP) with 5’ to 3’ exonuclease digestion. Since different regulatory complexes will result in different protein-DNA crosslinking signatures, analysis of ChIP-exo sequencing tag patterns should enable detection of multiple protein-DNA binding modes for a given regulatory protein. However, current ChIP-exo analysis methods either treat all binding events as being of a uniform type, or rely on the presence of DNA motifs to cluster binding events into subtypes. To systematically detect multiple protein-DNA interaction modes in a single ChIP-exo experiment, we introduce the ChIP-exo mixture model (ChExMix). ChExMix probabilistically models the genomic locations and subtype membership of protein-DNA binding events using both ChIP-exo tag enrichment patterns and DNA sequence information, thus offering a principled and robust approach to characterizing binding subtypes in ChIP-exo data. We demonstrate that ChExMix achieves accurate detection and classification of binding event subtypes using in silico mixed ChIP-exo data. We further demonstrate the unique analysis abilities of ChExMix using a collection of ChIP-exo experiments that profile the binding of key transcription factors in MCF-7 cells. In these data, ChExMix detects cooperative binding interactions between FoxA1, ERalpha, and CTCF, thus demonstrating that ChExMix can effectively stratify ChIP-exo binding events into biologically meaningful subtypes.
Project description:The emerging evidences support that exosome cargo miRNAs function as important regulators in cell differentiation. Therefore, in order to figure out the mechanism that Exo-AT mediated adipogenesis, we profiled miRNAs in Exo-AT using high-throughput sequencing (miRNA-seq). After trimming low-quality reads, contaminants, adaptors, and reads smaller than 15 nt, the remaining reads were mapped to merged pre-miRNA data bases. To identify the conserved miRNAs in Exo exosomes, miRNAs were aligned to miRBase v21. 148 and 154 types of known miRNAs in Exo-ADSCs and Exo-AT, respectively, were identified in the two replicates. Among these miRNAs, 103 miRNAs were simultaneously detected in both Exo-ADSCs and Exo-AT. Compared to Exo-ADSCs, 45 conserved miRNAs were enriched (expressed ≥ 2 folds, FDR<0.05) in Exo-AT. KEGG Pathway analysis was performed for the targets of the most 20 enriched miRNAs in Exo-AT (compared with Exo-ADSCs) to determine their potential function. Data showed that pathways that regulate adipogenesis such as Wnt signaling pathway, Insulin signaling pathway, MAPK signaling pathway, TGF-ß signaling pathway were enriched significantly for targets of Exo-AT miRNAs. Furthermore, 14 of 45 enriched miRNAs in Exo-AT (31.11%, such as miR-30a-5p, miR-148a-3p) were reported to participate in regulation of adipogenesis while 8 miRNAs (17.78%, such as miR-93-5p, miR-150-3p) that negatively control osteoblastic differentiation of MSC have been described.
Project description:Background and Aims: Although the zinc finger transcription factor GATA4 has been implicated in regulating jejunal gene expression, the contribution of GATA4 in controlling jejunal physiology has not been addressed. Methods: We generated mice in which the Gata4 gene was specifically deleted in the small intestinal epithelium. Measurements of plasma cholesterol and phospholipids, intestinal absorption of dietary fat and cholesterol, and gene expression were performed on these animals. Results: Mice lacking GATA4 in the intestine displayed a dramatic block in their ability to absorb cholesterol and dietary fat. Comparison of the global gene expression profiles of control jejunum, control ileum, and GATA4 null jejunum by gene array analysis demonstrated that GATA4 null jejunum lost expression of 53% of the jejunal-specific gene set and gained expression of 47% of the set of genes unique to the ileum. These alterations in gene expression included a decrease in mRNAs encoding lipid and cholesterol transporters as well as an increase in mRNAs encoding proteins involved in bile acid absorption. Conclusion: Our data demonstrate that GATA4 is essential for jejunal function including fat and cholesterol absorption and confirm that GATA4 plays a pivotal role in determining jejunal versus ileal identity. Experiment Overall Design: Total RNA was harvested from the following sources and used to Affymetrix array analysis following manufacturer defined protocols: Experiment Overall Design: control jejunum (Gata4loxP/+VilCre), 3 male mice, adult (6-8 wk) Experiment Overall Design: mutant jejunum (Gata4loxP/-VilCre), 3 male mice, adult (6-8 wk) Experiment Overall Design: control ileum (Gata4loxP/+VilCre), 3 male mice, adult (6-8 wk). Experiment Overall Design: A total of nine Mouse Genome 430_2.0 arrays were hybridized for this study. Experiment Overall Design: Jejunum was defined as 10 cm from the pyloric sphincter, and ileum was defined as 1 cm from the cecum. The animals used to harvest control jejunum and ileum were independent of each other.
Project description:To explore the possibility of miRNA(s) contributing to the cardioprotection induced by plasma exosomes at the late phase of RIPC, we performed a miRNA profiling assay (763 rat miRNAs) comparing the differences between RIPC-exo and Control-exo using Illumina HiSeq 2500 high-throughput sequencing.
Project description:Chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) and its ultra-high resolution cousin ChIP-exo are methods that identify where proteins bind along any genome in vivo. ChIP-exo achieves near-base pair resolution by creating exonuclease stop sites just 5’ to where formaldehyde-induced protein-DNA cross-links occur. Whereas construction of ChIP genomic libraries is straightforward and widely adopted for ChIP-seq, ChIP-exo is technically more involved which has resulted in limited adoption. Here we describe multiple ChIP-exo protocols, each with use-specific advantages and limitations. The new versions are greatly simplified through removal of multiple enzymatic steps. This is achieved in part through the use of Tn5 tagmentation and/or single-stranded DNA ligation. The result is greater library yields, lower processing time, and lower cost. A similar streamlined approach was developed for ChIP-seq, called ChIP-seq 1-step, where library construction is achieved in one-step.
Project description:Analysis of changes in gene expression following hepatocyte specific deletion of GATA4 in adult mice. Results showed that the subset of differentially expressed genes had liver specific ontologies. Total RNA isolated from hepatocytes of AAV8-Tbg-Cre injected GATA4 fl/fl mice was compared to total RNA isolated from AAV-Tbg-GFP injected GATA4 fl/fl mice.
Project description:The aim of this study was to induce cardiomyogenic conversion of Human Umbilical Vein Endothelial Cells (HUVEC ) by triggering ectopic expression of the cardiac transcription factors Nkx2.5 and GATA4. Cells were cultured without cell myocardial co-culture system and transduced with lentivirus containing coding sequence of Nkx2.5, GATA4 or GFP as control. Cells were cultured in the EBM-2/ EGM-2 medium, 12 days before microarray analysis. We report in this study that over-expression of NKX2.5 and GATA4 in HUVECs stimulates the expression of some specific genes important in the cardiomyogenic differentiation process, leading to partial switch of these cells from the endothelial to the myocardial course. 12 arrays were analysed. Three competitive hybridizations to the arrays were performed in duplicate using each time, two dye-swap following this experimental design: AWA065 : CY5 (HUVEC+NKX2,5) / CY3 (HUVEC) AWA067 : CY5 (HUVEC) / CY3 (HUVEC+NKX2,5) AWA075 : CY5 (HUVEC+NKX2,5) / CY3 (HUVEC) AWA076 : CY5 (HUVEC) / CY3 (HUVEC+NKX2,5) AWA068 : CY5 ((HUVEC) / CY3 (HUVEC+GATA4) AWA070 : CY5 (HUVEC+GATA4) / CY3 ((HUVEC) AWA073 : CY5 (HUVEC+GATA4) / CY3 ((HUVEC) AWA002 : CY5 ((HUVEC) / CY3 (HUVEC+GATA4) AWA066 : CY5 (HUVEC) / CY3 (HUVEC+NKX2.5+GATA4) AWA069 : CY5 (HUVEC+NKX2.5+GATA4) / CY3 (HUVEC) AWA071 : CY5 (HUVEC+NKX2.5+GATA4) / CY3 (HUVEC) AWA074 ; CY5 (HUVEC) / CY3 (HUVEC+NKX2.5+GATA4)
Project description:Cardiac malformations due to aberrant development of the atrioventricular (AV) valves are among the most common forms of congenital heart disease. At localized swellings of extracellular matrix known as the endocardial cushions, the endothelial lining of the heart undergoes an epithelial to mesenchymal transition (EMT) to form mesenchymal progenitors of the AV valves. Further growth and differentiation of these mesenchymal precursors results in formation of portions of the atrial and ventricular septae, and generation of thin, pliable valves. The transcription factor Gata4 is expressed in the endothelium and mesenchyme of the AV valves. Using a Tie2-Cre transgene, we selectively inactivated Gata4 within endothelial-derived cells. Mutant endothelium failed to undergo EMT, resulting in hypocellular cushions. Mutant cushions had decreased levels of Erbb3, an EGF-family receptor essential for EMT in the atrioventricular cushions. In Gata4 mutant embryos, Erbb3 downregulation was associated with impaired activation of Erk, which is also required for EMT. Expression of a Gata4 mutant protein defective in interaction with Friend of Gata (FOG) cofactors rescued the EMT defect, but resulted in decreased proliferation of mesenchyme and hypoplastic cushions that failed to septate the ventricular inlet. We demonstrate two novel functions of Gata4 in development of the AV valves. First, Gata4 functions as an upstream regulator of an Erbb3-Erk pathway necessary for EMT, and second, Gata4 acts to promote cushion mesenchyme growth and remodeling. Experiment Overall Design: To further investigate the role of Gata4 in EC development, we specifically inactivated Gata4 in endothelium and endothelium-derived cushion mesenchyme. All mice were maintained in a mixed C57BL6/129 genetic background. Gata4wt/flox; T2Cre+ mice were crossed with Gata4flox/flox mice to yield Gata4flox/flox (CONTROL); T2Cre+ (Gata4T2del) (MUTANT) mice.