Project description:Previously published results from our double-blind, placebo-controlled parallel study with docosahexaenoic acid (DHA) supplementation (3 g/d, 90 d) to hypertriglyceridemic men (39-66yr) showed that DHA reduced several risk factors for cardiovascular disease (CVD), including the plasma concentration of inflammatory markers. To determine the effect of DHA supplementation on the global gene expression pattern, we performed Affymetrix GeneChip microarray analysis of blood cells (treated with lipopolysaccharide (LPS) or vehicle) drawn before and after the supplementation from the hyperlipidemic men who participated in the previous study. Genes that were significantly differentially regulated by the LPS treatment and DHA supplementation were identified. Differential regulation of 18 genes was then confirmed by quantitative RT-PCR. Both microarray and qRT-PCR data showed that the expression of LDL receptor (LDLR), oxidized LDL receptor (OLR1), and cathepsin L1 (CTSL) was significantly suppressed by DHA supplementation; however, LPS stimulated the expression of LDLR and CTSL but not that of OLR1. LPS up-regulated and DHA suppressed the expression of prostaglandin E synthase (PTGES), PPAR delta, and various chemokines. Enrichment with Gene Ontology categories demonstrated that the genes related to transcription factor activity, immune responses, host defense responses, inflammatory responses, and apoptosis were inversely regulated by LPS and DHA. These results provide supporting evidence for the anti-inflammatory effects of DHA supplementation, and reveal previously unrecognized genes that are regulated by DHA, and are associated with risk factors of cardiovascular diseases. Double-blind, placebo-controlled parallel study with DHA supplementation to hypertriglyceridemic men. Gene expression detected in LPS-stimulated (LPS) and unstimulated (vehicle) white blood cells. 3-4 replicates per group.
Project description:Previously published results from our double-blind, placebo-controlled parallel study with docosahexaenoic acid (DHA) supplementation (3 g/d, 90 d) to hypertriglyceridemic men (39-66yr) showed that DHA reduced several risk factors for cardiovascular disease (CVD), including the plasma concentration of inflammatory markers. To determine the effect of DHA supplementation on the global gene expression pattern, we performed Affymetrix GeneChip microarray analysis of blood cells (treated with lipopolysaccharide (LPS) or vehicle) drawn before and after the supplementation from the hyperlipidemic men who participated in the previous study. Genes that were significantly differentially regulated by the LPS treatment and DHA supplementation were identified. Differential regulation of 18 genes was then confirmed by quantitative RT-PCR. Both microarray and qRT-PCR data showed that the expression of LDL receptor (LDLR), oxidized LDL receptor (OLR1), and cathepsin L1 (CTSL) was significantly suppressed by DHA supplementation; however, LPS stimulated the expression of LDLR and CTSL but not that of OLR1. LPS up-regulated and DHA suppressed the expression of prostaglandin E synthase (PTGES), PPAR delta, and various chemokines. Enrichment with Gene Ontology categories demonstrated that the genes related to transcription factor activity, immune responses, host defense responses, inflammatory responses, and apoptosis were inversely regulated by LPS and DHA. These results provide supporting evidence for the anti-inflammatory effects of DHA supplementation, and reveal previously unrecognized genes that are regulated by DHA, and are associated with risk factors of cardiovascular diseases.
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:Evidence is accumulating that nutritional exposures in utero can influence health outcomes in later life. Animal studies and human epidemiological studies have implicated epigenetic modifications as playing a key role in this process, but there are limited data from large well-controlled human intervention trials. This study utilised a large double-blind randomized placebo-controlled trial to test whether a defined nutritional exposure in utero, in this case docosahexaenoic acid (DHA), could alter the infant epigenome. Pregnant mothers consumed DHA-rich fish oil (800 mg DHA/d) or placebo supplements from 20 weeks’ gestation to delivery. Blood spots were collected from the children at birth (n=991) and blood leukocytes at 5 years (n=667). Global DNA methylation was measured in all samples and Illumina HumanMethylation450K BeadChip arrays were used for genome-wide methylation profiling in a subset of 369 children at birth and 65 children at 5 years. There were no differences in global DNA methylation levels between the DHA and control group either at birth or at 5 years, but we identified 21 differentially methylated regions (DMRs) at birth, showing small DNA methylation differences (<5%) between the treatment groups, some of which seemed to persist until 5 years. The number of DMRs at birth was greater in males (127 DMRs) and in females (72 DMRs) separately, indicating a gender-specific effect. In conclusion, maternal DHA supplementation during the second half of pregnancy had small effects on DNA methylation of infants. While the potential functional significance of these changes remains to be determined, these findings further support the role of epigenetic modifications in developmental programming in humans, and points the way for future studies.
Project description:In this study, we have examined the effect of combined prenatal Lactobacillus reuteri and omega-3 fatty acid supplementation on DNA methylation patterns in neonatal immune cells from children with a high propensity of developing allergies. We addressed this matter by assessing epigenome-wide DNA methylation patterns in CD4+ T helper cells obtained at birth, using the Illumina MethylationEPIC 850K array. Samples were retrieved from all four arms of the on-going PRObiotics and OMega-3 (PROOM-3, ClinicalTrials.gov-ID: NCT01542970) allergy prevention trial, and treatment-induced differential methylation as well as network modules were assessed.
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:Cortical thickness has been investigated since the beginning of the 20th century, but we do not know how similar the cortical thickness profiles among humans are. In this study, the local similarity of cortical thickness profiles was investigated using sliding window methods. Here, we show that approximately 5% of the cortical thickness profiles are similarly expressed among humans while 45% of the cortical thickness profiles show a high level of heterogeneity. Therefore, heterogeneity is the rule, not the exception. Cortical thickness profiles of somatosensory homunculi and the anterior insula are consistent among humans, while the cortical thickness profiles of the motor homunculus are more variable. Cortical thickness profiles of homunculi that code for muscle position and skin stimulation are highly similar among humans despite large differences in sex, education, and age. This finding suggests that the structure of these cortices remains well preserved over a lifetime. Our observations possibly relativize opinions on cortical plasticity.
Project description:Docosahexaenoic acid (DHA) is well known to promote visual and brain development while its protective effect on intestinal development in early life remains unknown. In order to understand the underlying biological effects of maternal DHA supplementation during lactation on the intestinal development of pups, we analyzed the proteomics of jejunum tissues from three groups with the DIA-MS method.