Identification of intergenic trans-regulatory RNAs containing a disease-linked SNP sequence and targeting cell cycle progression/differentiation pathways in multiple common human disorders

Abstract

Meta-analysis of genomic coordinates of SNP variations identified in genome-wide association studies (GWAS) of up to 712,253 samples (comprising 221,158 disease cases, 322,862 controls, and 168,233 case/control subjects of obesity GWAS) reveals that 39% of SNPs associated with 22 common human disorders are located within intergenic regions. Chromatin-state maps based on H3K4me3-H3K36me3 signatures show that many intergenic disease-linked SNPs are located within the boundaries of the K4-K36 domains, suggesting that SNP-harboring genomic regions are transcribed. Here we report identification of 13 trans-regulatory RNAs (transRNAs) 100 to 200 nucleotides in length containing intergenic SNP sequences associated with Crohn's disease, rheumatoid arthritis, type 1 diabetes, vitiligo, and multiple types of epithelial malignancies (prostate, breast, ovarian, and colorectal cancers). We demonstrate that NALP1 loci intergenic SNP sequence, rs2670660, is expressed in human cells and may contribute to clinical manifestations of autoimmune and autoimflammatory phenotypes by generating distinct allelic variants of transRNAs. Stable expression of allele-specific sense and anti-sense variants of transRNAs markedly alters cellular behavior, affect cell cycle progression, and interfere with monocyte/macrophage transdifferentiation. On a molecular level, forced expression of allele-specific sense and anti-sense variants of transRNAs asserts allele-specific genome-wide effects on abundance of hundreds microRNAs and mRNAs. Using lentiviral gene transfer, microarray and Q-RT-PCR technologies, we identify rs2670660 allele-specific gene expression signatures (GES) which appear useful for detecting the activated states of innate immunity/inflammasome pathways in ~700 clinical samples from 185 control subjects and 350 patients diagnosed with 9 common human disorders, including Crohn's disease, ulcerative colitis, rheumatoid arthritis, Huntington's disease, autism, Alzheimer's disease, obesity, prostate and breast cancers. Microarray analysis of clinical samples demonstrates that rs2670660 allele-specific GES are engaged in patients' peripheral blood mononuclear cells (PBMC) which encounter pathological conditions in coherent tissues of a human body during immune surveillance and homeostasis monitoring. These data indicate that expression of transRNAs encoded by specific intergenic sequences can trigger activation of innate immunity/inflammasome pathways and contribute to clinical development of autoinflammatory and autoimmune syndromes. Documented in this work single-base substitution-driven molecular and biological antagonisms of intergenic SNP-containing transRNAs suggest a guiding mechanism of selection and retention of phenotype-compatible intergenic variations during evolution. According to this model, random genetic variations which generate transRNAs asserting antagonistic phenotype-altering effects compared to ancestral alleles will be selected and retained as SNP variants.