In-vivo targeted tagging of RNA isolates cell specific transcriptional responses to environmental stimuli and identifies liver-to-adipose RNA transfer

J. Darr; M. Lassi; Archana Tomar; R. Gerlini; F. Scheid; M. Hrabe de Angelis; M. Witting; R. Teperino

The number of transcripts found to be enriched following pull-down in liver, plasma and VsWAT 404 was 9.7 folds greater than expected by chance for HFD and 6.8 folds greater than expected for Total RNA sequencing of VsWAT identified 100 genes to be differentially expressed following 416 acute HFD feeding (28 upregulated / 72 downregulated, Sup table 12). As expected given the 417 increased dietary intake of free fatty acids following HFD feeding, downregulation of Srebf1 and 418 of several target genes involved in fatty acid biosynthesis such as FasN, Acaca, and Scd2 is evident 419 (Figure 6c-d) . (Figure 4b-g) . In addition, environmentally induced transcriptional reprogramming is evident 469 following labelling (Figure 4h-k) . As opposed to recently described methods [14, 17, 20, 22] and Critically, and uniquely to iTag-RNA, we are also able to enrich for liver derived plasma ccfRNA 474 following an administration of multiple doses of HD5EU ( Figure 5) . Pulled-down plasma 475 ccfRNAs demonstrate an enrichment for liver derived RNA fragments of protein-coding genes, 476 whilst depleted transcripts demonstrate an enrichment for annotation relating to function and 477 differentiation of the hematopoietic system. Apart from fragments of protein coding genes, liver 478 secreted ccfRNA include various small RNA transcripts such as miRNA, mt-tRNAs and tRNAs.