Project description:Background: In a recent intervention study, the daily supplementation with 200mg monomeric and oligomeric flavanols (MOF) from grape seeds for 8 weeks revealed a vascular health benefit in male smokers. The objective of the present study was to determine the impact of MOF consumption on the gene expression profile of leukocytes and to assess changes in DNA methylation. Methodology/Principal Findings: Gene expression profiles were determined using whole genome microarrays (Agilent) and DNA methylation was assessed using HumanMethylation450 BeadChips (Illumina). MOF significantly modulated the expression of 869 genes. The majority of the affected genes are involved in chemotaxis, cell adhesion, cell infiltration or cytoskeleton organisation, suggesting lower immune cell adhesion to endothelial cells. This was corroborated by in vitro experiments showing that MOF exposure of monocytes attenuates their adhesion to TNFM-NM-1-stimulated endothelial cells. Nuclear factor-kappa B reporter gene assays confirmed that MOF decrease the activity of NF-M-NM-:B. Strong inter-individual variability in the leukocytes DNA methylation was observed. As a consequence, on group level, changes due to MOF supplementation could not be found. However, in individuals, significant changes in DNA methylation of genes involved in leukocyte rolling, adhesion and cytoskeleton remodelling were seen. At the group level, the variation in DNA methylation related to life style and clinical parameters appeared to overrule the magnitude of effects of supplementation with MOF. Conclusion: Our study revealed that regular consumption of MOF modulates the expression of genes in immune cells which, however, cannot be correlated to alterations in the DNA methylome. Remarkably, at the individual level, genes related to leukocyte adhesion pathways present complex variation in DNA methylation. As such, the individual transcriptional and epigenetic modulation of genes involved in early manifestation of cardiovascular diseases constitutes important subcellular mechanisms by which MOF promote vascular health in humans. Two-colors experiment, 7 volunteers : blood samples of 7 men, before and after an intervention of 8 weeks with daily intake of MOF (14 samples).
Project description:Background: In a recent intervention study, the daily supplementation with 200 mg monomeric and oligomeric flavanols (MOF) from grape seeds for 8 weeks revealed a vascular health benefit in male smokers. The objective of the present study was to determine the impact of MOF consumption on the gene expression profile of leukocytes and to assess changes in DNA methylation. Methodology/Principal Findings: Gene expression profiles were determined using whole genome microarrays (Agilent) and DNA methylation was assessed using HumanMethylation450 BeadChips (Illumina). MOF significantly modulated the expression of 864 genes. The majority of the affected genes are involved in chemotaxis, cell adhesion, cell infiltration or cytoskeleton organisation, suggesting lower immune cell adhesion to endothelial cells. This was corroborated by in vitro experiments showing that MOF exposure of monocytes attenuates their adhesion to TNF-M-NM-1-stimulated endothelial cells. Nuclear factor-kappa B (NF-M-NM-:B) reporter gene assays confirmed that MOF decrease the activity of NF-M-NM-:B. Strong inter-individual variability in the leukocytesM-bM-^@M-^Y DNA methylation was observed. As a consequence, on group level, changes due to MOF supplementation could not be found. However, in individuals, significant changes in DNA methylation of genes involved in leukocyte rolling, adhesion and cytoskeleton remodelling were seen. Conclusion: Our study revealed that regular consumption of MOF modulates the expression of genes in immune cells which, however, cannot be correlated to alterations in the DNA methylome. Remarkably, at the individual level, genes related to leukocyte adhesion pathways present complex variation in DNA methylation. As such, the individual transcriptional and epigenetic modulation of genes involved in early manifestation of cardiovascular diseases constitutes important subcellular mechanisms by which MOF promote vascular health in humans. DNA methylation levels of blood samples from 10 subjects were assessed using HumanMethylation450 BeadChips (Illumina), both before and after a diet intervention with MOF.
Project description:Background: In a recent intervention study, the daily supplementation with 200 mg monomeric and oligomeric flavanols (MOF) from grape seeds for 8 weeks revealed a vascular health benefit in male smokers. The objective of the present study was to determine the impact of MOF consumption on the gene expression profile of leukocytes and to assess changes in DNA methylation. Methodology/Principal Findings: Gene expression profiles were determined using whole genome microarrays (Agilent) and DNA methylation was assessed using HumanMethylation450 BeadChips (Illumina). MOF significantly modulated the expression of 864 genes. The majority of the affected genes are involved in chemotaxis, cell adhesion, cell infiltration or cytoskeleton organisation, suggesting lower immune cell adhesion to endothelial cells. This was corroborated by in vitro experiments showing that MOF exposure of monocytes attenuates their adhesion to TNF-α-stimulated endothelial cells. Nuclear factor-kappa B (NF-κB) reporter gene assays confirmed that MOF decrease the activity of NF-κB. Strong inter-individual variability in the leukocytes’ DNA methylation was observed. As a consequence, on group level, changes due to MOF supplementation could not be found. However, in individuals, significant changes in DNA methylation of genes involved in leukocyte rolling, adhesion and cytoskeleton remodelling were seen. Conclusion: Our study revealed that regular consumption of MOF modulates the expression of genes in immune cells which, however, cannot be correlated to alterations in the DNA methylome. Remarkably, at the individual level, genes related to leukocyte adhesion pathways present complex variation in DNA methylation. As such, the individual transcriptional and epigenetic modulation of genes involved in early manifestation of cardiovascular diseases constitutes important subcellular mechanisms by which MOF promote vascular health in humans.
Project description:Background: In a recent intervention study, the daily supplementation with 200mg monomeric and oligomeric flavanols (MOF) from grape seeds for 8 weeks revealed a vascular health benefit in male smokers. The objective of the present study was to determine the impact of MOF consumption on the gene expression profile of leukocytes and to assess changes in DNA methylation. Methodology/Principal Findings: Gene expression profiles were determined using whole genome microarrays (Agilent) and DNA methylation was assessed using HumanMethylation450 BeadChips (Illumina). MOF significantly modulated the expression of 869 genes. The majority of the affected genes are involved in chemotaxis, cell adhesion, cell infiltration or cytoskeleton organisation, suggesting lower immune cell adhesion to endothelial cells. This was corroborated by in vitro experiments showing that MOF exposure of monocytes attenuates their adhesion to TNFα-stimulated endothelial cells. Nuclear factor-kappa B reporter gene assays confirmed that MOF decrease the activity of NF-κB. Strong inter-individual variability in the leukocytes DNA methylation was observed. As a consequence, on group level, changes due to MOF supplementation could not be found. However, in individuals, significant changes in DNA methylation of genes involved in leukocyte rolling, adhesion and cytoskeleton remodelling were seen. At the group level, the variation in DNA methylation related to life style and clinical parameters appeared to overrule the magnitude of effects of supplementation with MOF. Conclusion: Our study revealed that regular consumption of MOF modulates the expression of genes in immune cells which, however, cannot be correlated to alterations in the DNA methylome. Remarkably, at the individual level, genes related to leukocyte adhesion pathways present complex variation in DNA methylation. As such, the individual transcriptional and epigenetic modulation of genes involved in early manifestation of cardiovascular diseases constitutes important subcellular mechanisms by which MOF promote vascular health in humans.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.