E-GEOD-37399 - Expression of Human DAMPmiRs
Released on 22 March 2013, last updated on 10 June 2014
Endogenous damage associated molecular pattern molecules (DAMPs) released from necrotic, damaged or stressed cells are associated with an inflammatory response. Whether the microRNA expression signature of this response is different from that of a PAMP-stimulated inflammatory response is unknown. We report here that miR-34c and miR-214 are significantly expressed in fresh human PBMCs exposed to DAMPcontaining freeze-thaw lysates, or to conditioned media from serum-starved and glucose-deprived cells (p<6x10-4 and p<3.7x10-3), respectively. Interestingly, only miR-34c expression was differentially expressed in PBMCs exposed to freeze-thaw lysates or conditioned media from HMGB1+/+ mouse embryonic fibroblast (MEF) cells, when compared to cultures exposed to lysates or conditioned media from HMGB1-/- MEFs. miR-155 expression in these cultures was negligible, but was significantly higher in PBMCs stimulated with LPS or most other TLR ligands, making it the prototypic PAMPmiR. Exposure to a damaged human colorectal carcinoma cell line lysate (HCT116) similarly resulted in increased miR-34c and miR-214 levels. When PBMCs were pre-transfected with anti-miR-34c and then exposed to lysate, expression levels of IKKgamma mRNA, a putative target of miR-34c, increased, while protein levels of IKKgamma in cultures transfected with a pre-miR-34c were abrogated. Levels of miR-34c expression (as well as pro-inflammatory cytokines, IL-1beta and TNFalpha) decreased when PBMC cultures were briefly pre-incubated with the K+ channel (inflammasome) inhibitor, glybenclamide, suggesting that miR-34c is involved in the inflammasome pathway in response to DAMPs. Our findings suggest that a specific microRNA expression signature is associated with the inflammatory response to damaged/injured cells and carries implications for many acute and chronic inflammatory disorders. Human PBMC (peripheral blood mononuclear cells) were exposed to 4 conditions for 48 hours. In the first condition, PBMCs were exposed to conditioned media from serum-starved and glucose-deprived and heat shocked HMGB1-/- MEF cells (mouse embryonic fibroblast cells). In the second condition, PBMCs were exposed to conditioned media from serum-starved and glucose-deprived and heat shocked HMGB1+/+ MEF cells (mouse embryonic fibroblast cells). In the third condition, PBMCs were exposed to LPS (Lipopolysaccharide). In the fourth condition, the PBMCs where left untreated. Four biological repeats were done for each condition for a total of 16 samples.
transcription profiling by RT-PCR
Damage associated molecular pattern molecule-induced microRNAs (DAMPmiRs) in human peripheral blood mononuclear cells. Unlu S, Tang S, Wang E, Martinez I, Tang D, Bianchi ME, Zeh HJ 3rd, Lotze MT. , Europe PMC 22745684