Abstract 375: The Intergenic Long Non-Coding RNA RP11-472n13.3 Modulates Interferon-Gamma Signaling and M1 Macrophage Activation

Abstract

We aim to interrogate the functions of a subset of human macrophage intergenic long non-coding RNA (lincRNAs) which harbor cardiometabolic trait-associated single nucleotide polymorphisms (SNPs). We have found that one lincRNA RP11-472N13.3 overlaps rs7081678, a SNP significantly associated with central obesity (WHRadjBMI; P =5.57x10 -6 ). RP11-472N13.3 expression is enriched in macrophages relative to other obesity relevant tissues. Thus, RP11-472N13.3 SNPs for obesity may act via its myeloid cell modulation in adipose. In human monocyte-derived macrophage (HMDM), human induced pluripotent stem cell-derived macrophages (IPSDM) and THP1-derived macrophages (THP-1Φ), at RNAseq and Q-PCR, RP11-472N13.3 is abundant in M0 and M2(IL-4) macrophages but markedly suppressed in the M1 state (LPS/IFNγ). RP11-472N13.3 localizes almost exclusively to the cytoplasmic fraction of M0-HMDM. Consistent with GENCODE, our HMDM RNAseq data suggest a single 2-exon isoform. ChIP-seq reveals PU.1 and C/EBP-β binding at RP11-472N13.3 transcription start site. In our HMDM RNAseq (n=30 subjects) data, RP11-472N13.3 expression was inversely correlated with IFNγ-JAK-STAT signaling genes (e.g., IRF4, IL-12A, IL-23, STAT1, SOCS1, SOCS3 ), but not LPS/TLR4 activated genes (e.g., TNFA, CXCL9, CXCL10, IL1B ). Furthermore, KD of RP11-472N13.3 using siRNA or LNA-ASO in THP-1Φ, amplified expression of IFNγ target genes but not LPS/TLR4 targets during M1 activation (LPS/IFNγ). These data suggest its potential role in modulating IFNγ signaling. Mechanistic studies are needed to examine the molecular mechanisms.