Genetic Factors in Nonsmokers with Age-Related Macular Degeneration Revealed Through Genome-Wide Gene-Environment Interaction Analysis
ANNALS OF HUMAN GENETICS
Authors: Naj, Adam C.; Scott, William K.; Courtenay, Monique D.; Cade, William H.; Schwartz, Stephen G.; Kovach, Jaclyn L.; Agarwal, Anita; Wang, Gaofeng; Haines, Jonathan L.; Pericak-Vance, Margaret A.
Abstract
Relatively little is known about the interaction between genes and environment in the complex etiology of age-related macular degeneration (AMD). This study aimed to identify novel factors associated with AMD by analyzing gene-smoking interactions in a genome-wide association study of 1207 AMD cases and 686 controls of Caucasian background with genotype data on 668,238 single nucleotide polymorphisms (SNPs) after quality control. Participants' history of smoking at least 100 cigarettes lifetime was determined by a self-administered questionnaire. SNP associations modeled the effect of the minor allele additively on AMD using logistic regression, with adjustment for age, sex, and ever/never smoking. Joint effects of SNPs and smoking were examined comparing a null model containing only age, sex, and smoking against an extended model including genotypic and interaction terms. Genome-wide significant main effects were detected at three known AMD loci: CFH (P= 7.51x1030), ARMS2 (P= 1.94x1023), and RDBP/CFB/C2 (P= 4.37x1010), while joint effects analysis revealed three genomic regions with P< 105. Analyses stratified by smoking found genetic associations largely restricted to nonsmokers, with one notable exception: the chromosome 18q22.1 intergenic SNP rs17073641 (between SERPINB8 and CDH7), more strongly associated in nonsmokers (OR= 0.57, P= 2.73 x 105), with an inverse association among smokers (OR= 1.42, P= 0.00228), suggesting that smoking modifies the effect of some genetic polymorphisms on AMD risk.
Genome-wide analysis of histone H3 lysine9 trimethylation by ChIP-seq in peripheral blood mononuclear cells of uremia patients
HEMODIALYSIS INTERNATIONAL
Authors: Sui, Weiguo; He, Huiyan; Yan, Qiang; Chen, Jiejing; Zhang, Ruohan; Dai, Yong
Abstract
Treatment of uremia is now dominated by dialysis, in some cases, patients are treated with dialysis for decades, but overall outcomes are disappointing. A number of studies have confirmed the relevance of several experimental insights to the pathogenesis of uremia, but the specific biomarkers of uremia have not been fully elucidated. Studies of the epigenome have attracted little interest in nephrology, especially in uremia. However, to date, our knowledge about the alterations in histone methylation in uremia is unclear. H3K9me3 variations were analyzed in peripheral blood mononuclear cells from 10 uremia patients and 10 healthy subjects, using chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq). There were 96 genes with significantly different expressions in the uremia patients compared with the normal controls. Forty-two increased and 54 decreased H3K9me3 genes displaying significant differences were found in uremia patients compared with healthy subjects. Five positive genes, ras-related C3 botulinum toxin substrate 3 (RAC3), polycomb group ring finger 2 (PCGF2), myosin heavy chain 3 (MYH3), noggin (NOG), serpin peptidase inhibitor 8 (SERPINB8), were selected and quantified. Our studies indicate that there are significant alterations of H3K9me3 in uremia patients; these significant H3K9me3 candidates may help to explain the immunological disturbance and high cardiovascular complications in uremia patients. Such novel findings show the significance of H3K9me3 as a potential biomarker or promising target for epigenetic-based uremia therapies.