5,5-Dimethyl-1-pyrroline N-oxide Modulates Transcriptome and Interactome Towards Dampening Innate Immune Response in RAW 264.7 cells

GOMEZ MEJIBA, S; MUNOZ M; RAMIREZ, DC; ALVAREZ SE

Congreso; The Society for Redox Biology and Medicine's 24th Annual Meeting; 2017

The nitrone spin trap 5,5-dimethyl-1-pyrroline N-oxide(DMPO) was originally synthesized for the study of freeradicals. However we found that DMPO can also preventinflammatory activation in RAW264.7 cells primed with lipopolysaccharide (LPS). Additionally, DMPO prevents lungdamage, adipose tissue inflammation, systemicinflammation and insulin resistance in a mouse model ofacute distress respiratory syndrome induced by intratrachealinstillation with LPS. These effects of DMPO are more likelycaused by changes in gene expression in innate immunecells. Thus herein we tested whether DMPO by itself canchange the transcriptome and interactome in RAW 264.7cells, as a model of macrophage. To accomplish our goal weincubated RAW 264.7 cells with (DMPO) or without(control) 50 mM DMPO for 6h. The transcriptome was analyzed using micro-array (Illumina) and corroborated byNanostring (nCounter) technology. Bioinformatics analysisshowed 79 differentially expressed genes (DEGs) in DMPO vs control comparison (ONE-way ANOVA; FDR = 0.05).DAVID databases for identifying enriched Gene Onthologyterms and Ingenuity Pathway Analysis (IPA) for functionalanalysis showed that DMPO DEGs were consistent with anegative regulation of innate immune response. Functionalanalysis indicated that IRF7 and TLRs were related(predicted inhibitions) to the observed transcriptomic effectsof DMPO. Functional data analyses are consistent withDMPO dampening LPS-induced inflammatory activation ofRAW 264.7 cells by down regulating several genes related tothe innate immune response. These effects were alsosupported by Nanostring data showing that DMPOdownregulates the expression of inflammation markers(CCL2, IFNβ, COX-2 and iNOS). Remarkably, our datasuggest that DMPO by itself shifts the transcriptomic profileof RAW264.7 cells towards a negative modulation of innateimmune response.