Gene Expression analysis of a differentiation timeseries of human Mesenchymal Stem Cells (hMSCs) in the presence of adipogenic/osteogenic factors. hMSCs differentiate into fat cells when treated with dexamethasone (10^-6 M), insulin (10 ug/ml), rosiglitazone (10^-7 M) and IBMX (250 uM). TGFbeta (5 ng/ml) inhibits this process and redirects these cells to differentiate into bone cells.
TGFβ-induced switch from adipogenic to osteogenic differentiation of human mesenchymal stem cells: identification of drug targets for prevention of fat cell differentiation.
Specimen part, Treatment, Time
View SamplesBackground: MicroRNAs (miRNAs) are a family of small, non-coding single-stranded RNA molecules involved in post-transcriptional regulation of gene expression. As such, they are believed to play a role in regulating the step-wise changes in gene expression patterns that occur during cell fate specification of multipotent stem cells. Here, we have studied whether terminal differentiation of C2C12 myoblasts is indeed controlled by lineage-specific changes in miRNA expression.
MicroRNA miR-378 promotes BMP2-induced osteogenic differentiation of mesenchymal progenitor cells.
Cell line
View SamplesOrofacial clefts (OFCs) are the most frequent craniofacial birth defects. An orofacial cleft (OFC) occurs as a result of deviations in palatogenesis. Cell proliferation, differentiation, adhesion, migration and apoptosis are crucial in palatogenesis. We hypothesized that deregulation of these processes in oral keratinocytes contributes to OFC. We performed microarray expression analysis on palatal keratinocytes from OFC and non-OFC individuals. Principal component analysis showed a clear difference in gene expression with 24 and 17% for the first and second component respectively. In OFC cells, 228 genes were differentially expressed (p<0.001). Gene ontology analysis showed enrichment of genes involved in β1 integrin-mediated adhesion and migration, as well as in P-cadherin expression. A scratch assay demonstrated reduced migration of OFC keratinocytes (343.6 ± 29.62 μm) vs. non-OFC keratinocytes (503.4 ± 41.81 μm, p<0.05). Our results indicate that adhesion and migration are deregulated in OFC keratinocytes, which might contribute to OFC pathogenesis.
Deregulated Adhesion Program in Palatal Keratinocytes of Orofacial Cleft Patients.
Specimen part
View SamplesMesenchymal progenitor cells can be differentiated in vitro into myotubes that exhibit many characteristic features of primary mammalian skeletal muscle fibers. However, in general, they do not show the functional excitation-contraction coupling or the striated sarcomere arrangement typical of mature myofibers. Epigenetic modifications have been shown to play a key role in regulating the progressional changes in transcription necessary for muscle differentiation. In this study, we demonstrate that treatment of murine C2C12 mesenchymal progenitor cells with 10 M of the DNA methylation inhibitor 5-azacytidine (5AC) promotes myogenesis, resulting in myotubes with enhanced maturity as compared to untreated myotubes. Specifically, 5AC treatment resulted in the upregulation of muscle genes at the myoblast stage while at later stages nearly 50 % of the 5AC-treated myotubes displayed a mature, well-defined sarcomere organization as well as spontaneous contractions that coincided with action potentials and intracellular calcium transients. Both the percentage of striated myotubes and their contractile activity could be inhibited by 20 nM TTX, 10 M ryanodine and 100 M nifedipine, suggesting that action potential-induced calcium transients are responsible for these characteristics. Our data suggest that genomic demethylation induced by 5AC overcomes an epigenetic barrier that prevents untreated C2C12 myotubes from reaching full maturity.
Epigenetics: DNA demethylation promotes skeletal myotube maturation.
Cell line, Treatment
View SamplesGene expression was influenced most by the tissue source, followed by culture methodology, next by location where the cells were cultured and lastly the donor variability.
The impact of cell source, culture methodology, culture location, and individual donors on gene expression profiles of bone marrow-derived and adipose-derived stromal cells.
Subject
View SamplesExpression profiles of anti-TNF responders were compared to profiles of anti-TNF non-responders in order to identify an expression signature for anti-TNF response
Validation study of existing gene expression signatures for anti-TNF treatment in patients with rheumatoid arthritis.
Specimen part, Disease, Disease stage, Treatment
View SamplesGlucocorticoids control expression of a large number of genes after binding to the glucocorticoid receptor (GR). Transcription may be regulated either by binding of the GR dimer to DNA regulatory elements or by protein-protein interactions of GR monomers with other transcription factors. Although the type of regulation for a number of individual target genes is known, the relative contribution of both mechanisms to the regulation of the entire transcriptional program remains elusive.
No associated publication
Sex, Specimen part
View SamplesWe assessed vastus lateralis muscle gene expression levels of 12 women with the metabolic syndrome before and after a 6 month exercise training program
Upregulation of skeletal muscle inflammatory genes links inflammation with insulin resistance in women with the metabolic syndrome.
Sex, Specimen part, Disease, Disease stage, Treatment, Subject, Time
View SamplesPolymorphonuclear cells (neutrophils) play an important role in the systemic inflammatory response syndrome and the development of sepsis. These cells are essential for the defense against microorganisms, but may also cause tissue damage. Therefore, neutrophil numbers and activity are considered to be tightly regulated. Previous studies have investigated gene transcription during experimental endotoxemia in whole blood and peripheral blood mononuclear cells. However, the gene transcription response of the circulating pool of neutrophils to systemic inflammatory stimulation in vivo is currently unclear. We examined neutrophil gene transcription kinetics in healthy human subjects (n=4) administered a single dose of endotoxin (LPS, 2 ng/kg iv). In addition, freshly isolated neutrophils were stimulated ex vivo with LPS, TNF, G-CSF and GM-CSF to identify stimulus-specific gene transcription responses. Whole transcriptome microarray analysis of circulating neutrophils at 2, 4 and 6 hours after LPS infusion revealed activation of inflammatory networks which are involved in signaling of TNF and IL-1 and IL-1. The transcriptome profile of inflammatory activated neutrophils in vivo reflects extended survival and regulation of inflammatory responses. We show that these changes in neutrophil transcriptome are most likely due to a combination of early activation of circulating neutrophils by TNF and G-CSF and a mobilization of young neutrophils from the bone marrow.
Transcriptome kinetics of circulating neutrophils during human experimental endotoxemia.
Specimen part
View SamplesDuring systemic inflammation, different neutrophil subsets are mobilized to the blood circulation. These neutrophil subsets can be distinguished from normal circulating neutrophils (CD16bright/CD62Lbright) based on either an immature CD16dim/CD62Lbright or a CD16bright/CD62Ldim phenotype. Interestingly, the latter neutrophil subset is known to suppress lymphocyte proliferation ex vivo, but the underlying mechanism is largely unknown.
IFN-γ-stimulated neutrophils suppress lymphocyte proliferation through expression of PD-L1.
Specimen part, Disease, Disease stage, Treatment
View Samples