Project description:Analysis of variation in subcutaneous adipose tissue gene expression in response to dietary intake of n-3 polyunsaturated fatty acids, as assessed in a cohot of individuals with metabolic syndrome. Outcomes from this study provide insight on molecular details of dietary effects on gene expression and metabolic health. Subcutaneous adipose tissue samples were taken from a cohort of seventeen individuals with metabolic syndrome. Habitual intake of n-3 polyunsaturated fatty acids was assessed with 3-day weighed food journals.
Project description:Analysis of variation in subcutaneous adipose tissue gene expression in response to dietary intake of n-3 polyunsaturated fatty acids, as assessed in a cohot of individuals with metabolic syndrome. Outcomes from this study provide insight on molecular details of dietary effects on gene expression and metabolic health.
Project description:The aim of the study is to establish the existence of a relationship between the dietary intake of polyunsaturated fatty acids (PUFA) and the risk of colorectal cancer in humans, using 2 reliable and complementary biomarkers: the fatty acid-composition of lipids of the abdominal subcutaneous adipose tissue and the fatty acid composition of erythrocyte phospholipids.
Project description:Acute effects of different dietary fatty acids on the gene expression profiles of peripheral blood mononuclear cells in healthy young men. A randomized cross-over study. Gene expression profiles of peripheral blood mononuclear cells (PBMCs) have been used to reflect pathological and physiological states of humans. We theorized that these cells could also be used to show fatty acid specific gene expression profiles. Since most individuals are in a postprandial state for the main part of the day, knowledge about acute effects of diet is highly valuable. In a cross over study, 21 healthy male volunteers were given shakes containing mainly polyunsaturated or saturated fatty acids. Before and 6 hours after intake of the shakes blood was taken and PBMCs were isolated to use for whole genome gene expression profiling, using Affymetrix NuGO_Hs1a52018 arrays. PUFA intake showed an decrease in LXR signaling and an increase in cellular stress response, while SFA intake showed an increase in LXR signaling.We conclude that PBMCs can reveal a fatty acid specific gene expression profile and in this study show an adverse effect on cellular stress responses of immune cells upon high PUFA intake. We hypothesize that these cells can therefore be used as biomarkers to reflect the capacity of cells to response to cellular stressors, such as fatty acids. Keywords: Acute fatty acid shake cross-over intervention study
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: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.
Project description:PurposeWe investigated the evidence of recent positive selection in the human phototransduction system at single nucleotide polymorphism (SNP) and gene level.MethodsSNP genotyping data from the International HapMap Project for European, Eastern Asian, and African populations was used to discover differences in haplotype length and allele frequency between these populations. Numeric selection metrics were computed for each SNP and aggregated into gene-level metrics to measure evidence of recent positive selection. The level of recent positive selection in phototransduction genes was evaluated and compared to a set of genes shown previously to be under recent selection, and a set of highly conserved genes as positive and negative controls, respectively.ResultsSix of 20 phototransduction genes evaluated had gene-level selection metrics above the 90th percentile: RGS9, GNB1, RHO, PDE6G, GNAT1, and SLC24A1. The selection signal across these genes was found to be of similar magnitude to the positive control genes and much greater than the negative control genes.ConclusionsThere is evidence for selective pressure in the genes involved in retinal phototransduction, and traces of this selective pressure can be demonstrated using SNP-level and gene-level metrics of allelic variation. We hypothesize that the selective pressure on these genes was related to their role in low light vision and retinal adaptation to ambient light changes. Uncovering the underlying genetics of evolutionary adaptations in phototransduction not only allows greater understanding of vision and visual diseases, but also the development of patient-specific diagnostic and intervention strategies.
Project description:Experimental studies confirmed n-6 type polyunsaturated fatty acid as pro-carcinogenic factor and n-3 fatty acid as cancer restraining agent; though their mode of action on tumor cells are still unclear. Keywords: Time course