Project description:Rosacea is a common chronic inflammatory skin disease of unknown etiology. Our knowledge about an involvement of the adaptive immune system is very limited. We performed detailed transcriptome analysis, qRT-PCR, and quantitative immunohistochemistry on facial biopsies of rosacea patients, classified according to their clinical subtype. As controls, we used samples from healthy controls. Our study shows significant activation of the immune system in all subtypes of rosacea, characterizing erythematotelangiectatic rosacea (ETR) already as a disease with significant influx of proinflammatory cells. The T cell response is dominated by Th1/Th17-polarized immune cells, as demonstrated by significant upregulation of IFNγ or IL-17, for example. Chemokine expression patterns support a Th1/Th17 polarization profile of the T cell response. Macrophages and mast cells are increased in all three subtypes of rosacea, while neutrophils reach a maximum in papulopustular rosacea. Our studies also provide evidence for activation of plasma cells with significant antibody production already in ETR, followed by a crescendo pattern towards phymatous rosacea. In sum, Th1/Th17 polarized inflammation and macrophage infiltration is an underestimated hallmark in all subtypes of rosacea. Therapies directly targeting the Th1/Th17 pathway are promising candidates in the future treatment of this skin disease. Total of 58 chips. 19 patients and 10 healthy volunteers
Project description:Rosacea is a common chronic inflammatory skin disease of unknown etiology. Our knowledge about an involvement of the adaptive immune system is very limited. We performed detailed transcriptome analysis, qRT-PCR, and quantitative immunohistochemistry on facial biopsies of rosacea patients, classified according to their clinical subtype. As controls, we used samples from healthy controls. Our study shows significant activation of the immune system in all subtypes of rosacea, characterizing erythematotelangiectatic rosacea (ETR) already as a disease with significant influx of proinflammatory cells. The T cell response is dominated by Th1/Th17-polarized immune cells, as demonstrated by significant upregulation of IFNγ or IL-17, for example. Chemokine expression patterns support a Th1/Th17 polarization profile of the T cell response. Macrophages and mast cells are increased in all three subtypes of rosacea, while neutrophils reach a maximum in papulopustular rosacea. Our studies also provide evidence for activation of plasma cells with significant antibody production already in ETR, followed by a crescendo pattern towards phymatous rosacea. In sum, Th1/Th17 polarized inflammation and macrophage infiltration is an underestimated hallmark in all subtypes of rosacea. Therapies directly targeting the Th1/Th17 pathway are promising candidates in the future treatment of this skin disease.
Project description:CD4+ T cells differentiate into phenotypically distinct T-helper cells upon antigenic stimulation. Regulation of plasticity between these CD4+ T-cell lineages is critical for immune homeostasis and prevention of autoimmune diseases. However, the factors that regulate lineage stability are largely unknown. Here we investigate a role for retinoic acid (RA) in the regulation of lineage stability using T helper 1 (Th1) cells, traditionally considered the most phenotypically stable Th subset. We found that RA, through its receptor RARa, sustains stable expression of Th1 lineage specifying genes as well as repressing genes that instruct Th17 cell fate. RA signaling is essential for limiting Th1 cell conversion into Th17 effectors and for preventing pathogenic Th17 responses in vivo. Our studies identify RA-RARa as a key component of the regulatory network governing Th1 cell fate and define a new paradigm for the development of pathogenic Th17 cells. These findings have important implications for autoimmune diseases in which dysregulated Th1-Th17 responses are observed. Identification of RARa binding in wild-type Th1 cells and mapping of enhancers using chromatin IP against p300, H3k4me1, H3k4me3, and H3k27ac in wild-type and dnRara Th1 cells.
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:CD4+ T cells are critical components in the human immune system. They produce cytokines to fight against pathogens and abnormal cells and stimulate other cells, such as B cells, macrophages, and neutrophils, to generate an immune response.
Naive CD4+ T cells are precursor cells that can differentiate into T helper - 1, - 2, - 17 (Th1, Th2, Th17) and regulatory T cells (Tregs) subtypes based on the type of pathogens or disease. The naive CD4+ T cell model consists of 5179 reactions, 3153 metabolites, and 1055 genes. Together with Th1, Th2, and Th17 models, the naive CD4+ T cell model helped identify drug targets and repurposable drugs against autoimmune diseases.
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:In this study, we examined differential gene expression in naïve human CD4+ T cells, as well as in effector Th1, Th17-negative and Th17-enriched CD4- T cell subsets. We observed a marked enrichment for increased gene expression in effector CD4+ T cells compared to naive CD4+ among immune-mediated disease oci genes. Within effector T cells, expression of disease-associated genes was increased in Th17-enriched compared to Th17-negative cells. We used microarray to examine the gene expresssion profile and level of human naïve, Th1 and effector T cell subsets. Human PBMCs were isolated and sorted to naïve, CD161-CCR6- and CD161+CCR6+ memory T cells. Naïve T cells were differentiatied to Th1 cells, and CD161-CCR6- and CD161+CCR6+ memory T cells were in vitro expanded for Th17-negative and Th17-enriched effector T cells. The gene profile was compared among naive, Th1, Th17-negative, and Th17-enriched cell subsets.
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.