Project description:Toxicogenomics (tgx) is used as a tool to identify mechanisms and markers of steatosis in C57BL/6 mice treated by oral gavage using amiodarone (AMD), valproic acid (VPA), and tetracycline (TET). Critical doses for tgx analysis were derived from a 25 day dose range finding study. For tgx analysis, livers of mice were collected after 1, 4, and 11 days of repeated treatment with 6.7, 20, and 60 mg/kg bw for AMD; 125, 250, and 500 mg/kg bw for VPA; and 14.8, 44, and 133 mg/kg bw for TET. For each treatment (compound and vehicle) in the toxicogenomics study samples were as follows: four at the high dose 1 and 4 day time point, and five at the low, medium, and high dose at 11 days. One set of vehicle controls were used for AMD and VPA (PBS), and TET had its own vehicle controls (milli-q water with ascorbic acid). The total number of samples was 95.
Project description:Age-related macular degeneration (AMD) is a major cause of blindness in the western world. While genetic studies have linked both common and rare variants in genes involved in regulation of the complement system to increased risk of development of AMD, environmental factors, such as smoking and nutrition, can also significantly affect the risk of developing the disease and the rate of disease progression. Since epigenetics has been implicated in mediating, in part, the disease risk associated with some environmental factors, we investigated a possible epigenetic contribution to AMD. We performed genome-wide DNA methylation profiling of blood from AMD patients and controls. No differential methylation site reached genome-wide significance; however, when epigenetic changes in and around known GWASdefined AMD risk loci were explored, we found small but significant DNA methylation differences in the blood of neovascular AMD patients near age-related maculopathy susceptibility 2 (ARMS2), a top-ranked GWAS locus preferentially associated with neovascular AMD. The methylation level of one of the CpG sites significantly correlated with the genotype of the risk SNP rs10490924, suggesting a possible epigenetic mechanism of risk. Integrating genome-wide DNA methylation analysis of retina samples with and without AMD together with blood samples, we further identified a consistent, replicable change in DNA methylation in the promoter region of protease serine 50 (PRSS50). These methylation changes may identify sites in novel genes that are susceptible to non-genetic factors known to contribute to AMD development and progression.
Project description:Age-related macular degeneration (AMD) is a complex multifactorial disease with at least 34 loci contributing to genetic susceptibility. To gain functional understanding of AMD genetics, we generated DNA methylation profiles of retina from 160 individuals including both controls and cases at distinct stages of AMD. With genotypes over 8 million common single nucleotide polymorphisms (SNPs) in cis, we identified 37,453 methylation quantitative trait loci (mQTL) and by integrating transcriptome of the same samples we identified 12,505 eQTLs and 13,747 DNAm sites that affect gene expression (eQTMs). We then integrated the AMD-genome-wide association studies (GWAS) data with mQTLs and eQTLs ascertained 87 target genes that may contribute to AMD risk. Our studies expand the methylation landscape of retina and AMD leading to direct targets for biological evaluation.
Project description:Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly. The extent to which epigenetic changes regulate the progression of AMD is unclear. Here we profiled chromatin accessibility in the retina and retinal pigmented epithelium (RPE) from AMD patients and controls. Global decreases in chromatin accessibility occur in the RPE in early AMD and in the retina with advanced disease. Footprints of photoreceptor and RPE-specific transcription factors are enriched in differentially accessible regions (DARs) and reduced AMD. Genes associated with DARs show altered expression in AMD. Cigarette smoke, an established risk factor for AMD, applied to human iPSC-derived RPE cells recapitulates epigenomic changes seen in AMD. In addition to providing a comprehensive profile of chromatin accessibility in human RPE and retina, this study shows that global decreases in chromatin accessibility may play a critical role in AMD progression.
Project description:In contrast to neovascular age-related macular degeneration (nAMD), no treatment option exists for dry AMD. The identification of specific biomarkers is required to facilitate diagnosis and therapy of dry AMD. We thus measured the proteome of 34 vitreous humor samples (dry AMD: n = 6, nAMD: n = 10, PDR: n = 9, ERM: n = 9). Samples were immunodepleted for high abundant blood proteins and analyzed by LC-MS/MS with a shotgun approach. Data from dry AMD, nAMD and PDR were compared to the ERM patient group, which was used as reference group. A bioinformatic pipeline was used for label-free relative quantification of proteins and to perform cluster analysis, gene ontology classification and gene set enrichment analysis. A selection of differentially regulated proteins was validated by ELISA. A total of 677 proteins were identified and relatively quantified in the four patient groups. Different clusters of regulated proteins for each patient group were identified and showed characteristic enrichment of specific pathways, like ‘oxidative stress’ for dry AMD, ‘focal adhesion’ for nAMD and ‘complement and coagulation cascade’ for PDR patients. We’ve identified CHLE to be specifically upregulated in dry AMD and RNAS1 together with CPVL to be upregulated in both forms of AMD. The description of pathways specific for the different patient groups and the identification of differentially regulated proteins provide a first step towards the definition of biomarkers for dry AMD. To validate these data and to unravel the mechanistic connection of identified proteins to dry AMD, larger patient cohorts need to be investigated.
Project description:To effectively monitor microbial populations in acidic environments and bioleaching systems, a comprehensive 50-mer-based oligonucleotide microarray was developed based on most of the known genes associated with the acidophiles. This array contained 1,072 probes in which there were 571 related to 16S rRNA and 501 related to functional genes. Acid mine drainage (AMD) presents numerous problems to the aquatic life and surrounding ecosystems. However, little is known about the geographic distribution, diversity, composition, structure and function of AMD microbial communities. In this study, we analyzed the geographic distribution of AMD microbial communities from twenty sites using restriction fragment length polymorphism (RFLP) analysis of 16S rRNA genes, and the results showed that AMD microbial communities were geographically distributed and had high variations among different sites. Then an AMD-specific microarray was used to further analyze nine AMD microbial communities, and showed that those nine AMD microbial communities had high variations measured by the number of detected genes, overlapping genes between samples, unique genes, and diversity indices. Statistical analyses indicated that the concentrations of Fe, S, Ca, Mg, Zn, Cu and pH had strong impacts on both phylogenetic and functional diversity, composition, and structure of AMD microbial communities. This study provides insights into our understanding of the geographic distribution, diversity, composition, structure and functional potential of AMD microbial communities and key environmental factors shaping them.
Project description:Background Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in the elderly population worldwide. Recent studies have demonstrated strong genetic associations between AMD and single nucleotide polymorphisms (SNPs) within genes such as CFH and HTRA1. However, we have identified monozygotic twins discordant for AMD phenotypes (one with disease, the other without disease), suggesting that an epigenetic mechanism may also contribute to the pathogenesis of AMD. Methods We identified two twin pairs with phenotypic discordance of AMD. We obtained genomic DNA from their peripheral blood mononuclear cells (PBMCs) and subjected them to DNA methylation-chip analysis (MeDIP-chip) that profiled genome-wide DNA methylation patterns on promoters of all genes and microRNAs. We next utilized the Methyl-Profiler DNA methylation assays to detect the methylation status of selected promoters. Flow cytometry and quantitative real-time PCR were used to detect the expression of the selected gene in peripheral blood cells, as well as in retinal and choroidal tissues of AMD patients and non-AMD controls. Results Our MeDIP-chip analysis identified 256 genes with hypo-methylated promoters only in the twins with AMD and 744 genes with hyper-methylated promoters only in the twins with AMD. Importantly, the promoter region of IL17RC was associated with hypo-methylated CpG sites only in the twins with AMD but not in the twins without AMD. We also found the association of the hypo-methylated IL17RC promoter with AMD in 7 pairs of siblings with discordant AMD pathology (P=0.003), as well as an independent patient cohort (95 neovascular wet and 107 geographic atrophy dry AMD patients as well as 96 non-AMD controls (95% CI, 0.01-0.10, P=9.8x10-8 for wet AMD vs. control; 95% CI, 0.05-0.32, P=2.2x10-5 for dry AMD vs. control)). Interestingly, we did not find an association between the levels of methylation on the IL17RC promoter with the previously identified genetic risk alleles in CFH, HTRA1, and ARMS2. We demonstrated an elevated expression of the IL-17RC protein in CD14+ monocytes in the peripheral blood of AMD patients as compared to non-AMD controls. These IL-17RC+ monocytes have elevated expression of CXCR1, CXCR2, and CXCR4. In addition, IL17RC was expressed only in the retinal and choroidal tissues from AMD patients but not from age-matched controls. Conclusions We show an association of the hypo-methylated IL17RC promoter with AMD, which resulted in the elevated expression of IL-17RC in peripheral blood cells as well as the retinal and choroidal tissues of AMD patients. Our study suggests that the hypo-methylated IL17RC promoter and elevated expression of IL-17RC can potentially serve as biomarkers for the diagnosis of AMD, while IL-17RC can be a new therapeutic target for AMD. In addition, our results strongly suggest an epigenetic control mechanism of AMD pathogenesis. The Affymetrix MOE430 2.0 GeneChip was used to detect gene expression patterns within the whole eye of C57B/6 normal mice.
Project description:To effectively monitor microbial populations in acidic environments and bioleaching systems, a comprehensive 50-mer-based oligonucleotide microarray was developed based on most of the known genes associated with the acidophiles. This array contained 1,072 probes in which there were 571 related to 16S rRNA and 501 related to functional genes. Acid mine drainage (AMD) presents numerous problems to the aquatic life and surrounding ecosystems. However, little is known about the geographic distribution, diversity, composition, structure and function of AMD microbial communities. In this study, we analyzed the geographic distribution of AMD microbial communities from twenty sites using restriction fragment length polymorphism (RFLP) analysis of 16S rRNA genes, and the results showed that AMD microbial communities were geographically distributed and had high variations among different sites. Then an AMD-specific microarray was used to further analyze nine AMD microbial communities, and showed that those nine AMD microbial communities had high variations measured by the number of detected genes, overlapping genes between samples, unique genes, and diversity indices. Statistical analyses indicated that the concentrations of Fe, S, Ca, Mg, Zn, Cu and pH had strong impacts on both phylogenetic and functional diversity, composition, and structure of AMD microbial communities. This study provides insights into our understanding of the geographic distribution, diversity, composition, structure and functional potential of AMD microbial communities and key environmental factors shaping them. This study investigated the geographic distribution of Acid Mine Drainages microbial communities using a 16S rRNA gene-based RFLP method and the diversity, composition and structure of AMD microbial communities phylogenetically and functionally using an AMD-specific microarray which contained 1,072 probes ( 571 related to 16S rRNA and 501 related to functional genes). The functional genes in the microarray were involved in carbon metabolism (158), nitrogen metabolism (72), sulfur metabolism (39), iron metabolism (68), DNA replication and repair (97), metal-resistance (27), membrane-relate gene (16), transposon (13) and IST sequence (11).