Genome-wide interrogation reveals hundreds of long intergenic noncoding RNAs that associate with cardiometabolic traits.

Long intergenic noncoding RNAs (lincRNAs) play important roles in disease, but the vast majority of these transcripts remain uncharacterized. We defined a set of 54 944 human lincRNAs by drawing on four publicly available lincRNA datasets, and annotated ∼2.5 million single nucleotide polymorphisms (SNPs) from each of 15 cardiometabolic genome-wide association study datasets into these lincRNAs. We identified hundreds of lincRNAs with at least one trait-associated SNP: 898 SNPs in 343 unique lincRNAs at 5% false discovery rate, and 469 SNPs in 146 unique lincRNAs meeting Bonferroni-corrected P < 0.05. An additional 64 trait-associated lincRNAs were identified using a class-level testing strategy at Bonferroni-corrected P < 0.05. To better understand the genomic context and prioritize trait-associated lincRNAs, we examined the pattern of linkage disequilibrium between SNPs in the lincRNAs and SNPs that met genome-wide-significance in the region (±500 kb of lincRNAs). A subset of the lincRNA-trait association findings was replicated in independent Genome-wide association studies data from the Pakistan Risk of Myocardial Infarction Study study. For trait-associated lincRNAs, we also investigated synteny and conservation relative to mouse, expression patterns in five cardiometabolic-relevant tissues, and allele-specific expression in RNA sequencing data for adipose tissue and leukocytes. Finally, we revealed a functional role in human adipocytes for linc-NFE2L3-1, which is expressed in adipose and is associated with waist-hip ratio adjusted for BMI. This comprehensive profile of trait-associated lincRNAs provides novel insights into disease mechanism and serves as a launching point for interrogation of the biology of specific lincRNAs in cardiometabolic disease.

Tissue-specific RNA-Seq in human evoked inflammation identifies blood and adipose LincRNA signatures of cardiometabolic diseases.

OBJECTIVE: Inappropriate transcriptional activation of innate immunity is a pathological feature of several cardiometabolic disorders, but little is known about inflammatory modulation of long intergenic noncoding RNAs (lincRNAs) in disease-relevant human tissues. APPROACH AND RESULTS: We applied deep RNA sequencing (>500 million filtered reads per sample) to blood and adipose during low-dose experimental endotoxemia (lipopolysaccharide) in a healthy human, with targeted replication in separate individuals undergoing endotoxemia (n=6), to identify inflammatory lincRNAs. A subset of these lincRNAs was examined for expression in adipocytes and monocytes, modulation in adipose of obese humans, and overlap with genome-wide association study signals for inflammatory and cardiometabolic traits. Of a stringent set of 4284 lincRNAs, ≈11% to 22% were expressed with 201 and 56 lincRNAs modulated by lipopolysaccharide in blood or adipose, respectively. Tissue-specific expression of a subset of 6 lipopolysaccharide-lincRNAs was replicated with lipopolysaccharide modulation confirmed for all 3 expressed in blood and 2 of 4 expressed in adipose. The broader generalizability of findings in blood of subject A was confirmed by RNA sequencing in 7 additional subjects. We confirmed adipocytes and monocytes as potential cell-sources of selective lipopolysaccharide-regulated lincRNAs, and 2 of these, linc-DMRT2 (P=0.002) and linc-TP53I13 (P=0.01), were suppressed in adipose of obese humans. Finally, we provide examples of lipopolysaccharide-modulated lincRNAs that overlap single nucleotide polymorphisms that are associated with cardiometabolic traits. CONCLUSIONS: Our findings provide novel insights into tissue-level, inflammatory transcriptome regulation in cardiometabolic diseases. These are complementary to more usual approaches limited to interrogation of DNA variations.