Project description:Analysis of non-differentiated Caco-2 intestinal epithelial cell line treated with polydextrose fermentation metabolites fermented for 48 hours in 4-stage in vitro colon simulator, in which the conditions mimic the human proximal, ascending, transverse and distal colon in sequence , as well as with medium, 100 mM NaCl and 5 mM butyrate. Polydextrose, a soluble fiber fermented in colon, was fermented with the in vitro colon simulator in three amounts of 0%, 1% and 2%. Results provide insight into the mechanisms underlying colon cancer cells and a comparison of a complex fiber metabolome to 5 mM butyrate and 100 mM NaCl. Furthermore, the results give insight of dosage effect of increasing the concentration of fiber. High level of dietary fiber has been epidemiologically linked to protection against the risk for developing colon cancer. The mechanisms of this protection are not clear. Fermentation of dietary fiber in the colon results in production of for example butyrate that has drawn attention as a chemopreventive agent. Polydextrose, a soluble fiber that is only partially fermented in colon, was fermented in an in vitro colon simulator, in which the conditions mimic the human proximal, ascending, transverse and distal colon in sequence. The subsequent fermentation metabolome were applied on colon cancer cells, and the gene expression changes studied. Polydextrose fermentation down-regulated classes linked with cell cycle, and affected number of metabolically active cells. Further, up-regulated effects on classes linked with apoptosis implicate that polydextrose fermentation plays a role in induction of apoptosis in colon cancer cells. The up-regulated genes involved also key regulators of lipid metabolism, such as PPARg and PGC-1α. These results offer hypotheses for the mechanisms of two health benefits linked with consumption of dietary fiber, reducing risk of development of colon cancer, and dyslipidemia. Non-differentiated Caco-2 cells were treated with polydextrose fermentation metabolites from the vessels representing different parts of the colon, or with 100 mM NaCl or with 5 mM butyrate for 24 hours. For polydextrose fermentation three concentrations of polydextrose were used: 0%, 1% and 2% for a simulation that lasted for 48 hours. Polydextrose fermentation samples from total of 12 vessels, as well as from medium sample, 5 mM butyrate and 100 mM NaCl were analysed as single replica.
Project description:Analysis of non-differentiated Caco-2 intestinal epithelial cell line treated with polydextrose fermentation metabolites fermented for 48 hours in 4-stage in vitro colon simulator, in which the conditions mimic the human proximal, ascending, transverse and distal colon in sequence , as well as with medium, 100 mM NaCl and 5 mM butyrate. Polydextrose, a soluble fiber fermented in colon, was fermented with the in vitro colon simulator in three amounts of 0%, 1% and 2%. Results provide insight into the mechanisms underlying colon cancer cells and a comparison of a complex fiber metabolome to 5 mM butyrate and 100 mM NaCl. Furthermore, the results give insight of dosage effect of increasing the concentration of fiber. High level of dietary fiber has been epidemiologically linked to protection against the risk for developing colon cancer. The mechanisms of this protection are not clear. Fermentation of dietary fiber in the colon results in production of for example butyrate that has drawn attention as a chemopreventive agent. Polydextrose, a soluble fiber that is only partially fermented in colon, was fermented in an in vitro colon simulator, in which the conditions mimic the human proximal, ascending, transverse and distal colon in sequence. The subsequent fermentation metabolome were applied on colon cancer cells, and the gene expression changes studied. Polydextrose fermentation down-regulated classes linked with cell cycle, and affected number of metabolically active cells. Further, up-regulated effects on classes linked with apoptosis implicate that polydextrose fermentation plays a role in induction of apoptosis in colon cancer cells. The up-regulated genes involved also key regulators of lipid metabolism, such as PPARg and PGC-1α. These results offer hypotheses for the mechanisms of two health benefits linked with consumption of dietary fiber, reducing risk of development of colon cancer, and dyslipidemia.
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: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.
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:As the evolution of miRNA genes has been found to be one of the important factors in formation of the modern type of man, we performed a comparative analysis of the evolution of miRNA genes in two archaic hominines, Homo sapiens neanderthalensis and Homo sapiens denisova, and elucidated the expression of their target mRNAs in bain.A comparative analysis of the genomes of primates, including species in the genus Homo, identified a group of miRNA genes having fixed substitutions with important implications for the evolution of Homo sapiens neanderthalensis and Homo sapiens denisova. The mRNAs targeted by miRNAs with mutations specific for Homo sapiens denisova exhibited enhanced expression during postnatal brain development in modern humans. By contrast, the expression of mRNAs targeted by miRNAs bearing variations specific for Homo sapiens neanderthalensis was shown to be enhanced in prenatal brain development.Our results highlight the importance of changes in miRNA gene sequences in the course of Homo sapiens denisova and Homo sapiens neanderthalensis evolution. The genetic alterations of miRNAs regulating the spatiotemporal expression of multiple genes in the prenatal and postnatal brain may contribute to the progressive evolution of brain function, which is consistent with the observations of fine technical and typological properties of tools and decorative items reported from archaeological Denisovan sites. The data also suggest that differential spatial-temporal regulation of gene products promoted by the subspecies-specific mutations in the miRNA genes might have occurred in the brains of Homo sapiens denisova and Homo sapiens neanderthalensis, potentially contributing to the cultural differences between these two archaic hominines.