Project description:using peripheral blood monocytes to identify marker genes for an extensively grown coronary collateral circulation. We used microarrays to detail the global programme of gene expression underlying collateralization and identified distinct classes of differently regulated genes during this process. Experiment Overall Design: Collateral flow index (CFI) was obtained invasively by angioplasty pressure sensor guidewire, a group of patients with coronary artery disease CAD and a group without CAD were selected for peripheral monocyte isolation, RNA extraction and hybridization on Affymetrix microarrays.
Project description:Background: Collateral artery growth, also termed arteriogenesis, occurs upon narrowing or occlusion of a major artery. To date, attempts to stimulate arteriogenesis in patients for therapeutic purposes have not been successful. Experimental models showed that circulating cells orchestrate arteriogenesis. In humans, a large heterogeneity exists in the arteriogenic response. We hypothesized that good arteriogenic responders (GARs) and bad arteriogenic responders (BARs) differ in gene expression profiles of circulating cells, thereby disclosing potential new therapeutic strategies for the stimulation of arteriogenesis. Methods: A total of 45 patients scheduled for percutaneous coronary intervention (PCI) for single-vessel coronary artery disease underwent intracoronary measurements of collateral flow index (CFI) to distinguish between GARs (CFI>0.21) and BARs (CFI≤0.21). Monocytes and CD34+ stem cells were collected from peripheral blood. A fraction of monocytes was further processed to obtain stimulated monocytes and macrophages. Whole genome transcriptome analysis was performed on all four cell types. Results: LPS-stimulated monocytes showed 244 genes differentially expressed (false discovery rate < 0.05) between GARs and BARs. Macrophage gene expression correlated with stimulated monocytes, while resting monocytes and stem cells revealed no differential gene expression. Stimulated monocytes from GARs showed a strongly attenuated response in several interferon- and apoptosis-related genes, which was corroborated at the protein level. Conclusions Circulating cells from GARs and BARs distinctively differ in their gene expression profiles upon stimulation. The reduced expression of interferon and apoptosis genes in GARs may lead to novel therapeutic approaches for the stimulation of collateral artery growth. Keywords: disease state analysis, stress response analysis, natural defense mechanism analysis
Project description:In the present study, we performed transcriptome expression analyses in three independent peripheral blood-derived monocyte subpopulations from patients with chronic coronary occlusions (CTO) and tested for arteriogenesis. Whole-genome mRNA expression analyses were performed on these three monocyte subpopulations, namely: (1) unstimulated-, (2) 3 hours LPS-stimulated-, (3) monocyte-derived macrophages. Whole-genome mRNA expression analysis amongst others confirmed increased expression of IFNbeta-regulated genes in patients with insufficient coronary collateralization (collateral flow index (CFI) ≤0.37 “nonresponders”), compared with patients having sufficient collateralization (CFI>0.37 “responders”).
Project description:Single-nucleus RNA sequencing (snRNA-seq) was used to profile the transcriptome of 16,015 nuclei in human adult testis. This dataset includes five samples from two different individuals. This dataset is part of a larger evolutionary study of adult testis at the single-nucleus level (97,521 single-nuclei in total) across mammals including 10 representatives of the three main mammalian lineages: human, chimpanzee, bonobo, gorilla, gibbon, rhesus macaque, marmoset, mouse (placental mammals); grey short-tailed opossum (marsupials); and platypus (egg-laying monotremes). Corresponding data were generated for a bird (red junglefowl, the progenitor of domestic chicken), to be used as an evolutionary outgroup.
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:Gene methylation profiling of immortalized human mesenchymal stem cells comparing HPV E6/E7-transfected MSCs cells with human telomerase reverse transcriptase (hTERT)- and HPV E6/E7-transfected MSCs. hTERT may increase gene methylation in MSCs. Goal was to determine the effects of different transfected genes on global gene methylation in MSCs.
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.