Abstract MP38: Functional Investigation Of A Novel Adipose Long Intergenic Non-coding RNA, Linc- ADAIN, During Obesity

Background: Long intergenic non-coding RNAs (lincRNAs) are important emerging regulators of cellular functions. Dysfunctional adipose tissue, characterized by increased inflammation and insulin resistance, plays a central role in the development of type 2 diabetes (T2DM) and atherosclerotic cardiovascular diseases. Deep RNA-sequencing of human adipose during low-dose endotoxemia, identified novel lincRNAs shown to be regulated by inflammation and were validated in an independent human cohort, before and after bariatric surgery. LincADAIN was identified as a top candidate that is 1)abundantly expressed in adipose tissue 2)reduced in both obesity-induced chronic and LPS-induced acute inflammation (-77% and -53%, p<0.05). Methods: Knock down(KD) of lincRNAs was carried out via lentiviral expression of shRNA and antisense oligonucleotides (ASOs) in human adipose stromal cells (ASCs)-adipocytes. Subcellular location of LincADAIN was identified through qPCR after cellular fractionation. Biotinylated lincRNA pulldown assay was used to identify interacting proteins by Mass Spectrometry (MS). Results: Human LincADAIN expression negatively correlates to BMI in obese (p<0.001, r2-0.3042) but not lean individuals. PPARγ antagonist treatment showed reduced expression of LincADAIN and PPARγ ChIP-seq peaks indicate that PPARγ may be a transcriptional activator. KD via shRNA of LincADAIN in ASC-adipocytes, increased protein but not mRNA levels of inflammatory cytokines in adipocytes such as IL-8 and MCP-1. Cellular fractionation experiments indicate that LincADAIN is mainly located in the nucleus. MS analysis of biotinylated LincADAIN pulldown proteins revealed many central nuclear and ribosomal proteins as potential interactors, which may be involved in the post-transcriptional mechanism of LincADAIN regulating inflammatory cytokines. Conclusion: These results suggest that LincADAIN is a novel lincRNA with roles in regulating adipose inflammation through nuclear and cytoplasmic actions including modulation of RNA translation. Functional investigations of lincRNAs, such as these are warranted, as recent genomic studies suggest that lincRNAs are likely the causal element driving human disease at some GWAS loci.