| Item type: | Article | ||||
|---|---|---|---|---|---|
| Journal or Publication Title: | RNA Biology | ||||
| Publisher: | TAYLOR & FRANCIS INC | ||||
| Place of Publication: | PHILADELPHIA | ||||
| Volume: | 13 | ||||
| Number of Issue or Book Chapter: | 1 | ||||
| Page Range: | pp. 43-58 | ||||
| Date: | 2016 | ||||
| Institutions: | Medicine > Lehrstuhl für Innere Medizin III (Hämatologie und Internistische Onkologie) Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie > Lehrstuhl für Biochemie I > Prof. Dr. Gunter Meister | ||||
| Identification Number: |
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| Keywords: | NF-KAPPA-B; ARGONAUTE PROTEIN COMPLEXES; INNATE IMMUNE-RESPONSES; GENE-EXPRESSION; IN-VITRO; TRANSLATION INITIATION; INFLAMMATORY RESPONSE; SIGNALING PATHWAY; INDUCED APOPTOSIS; CELL MATURATION; miR-155; post-transcriptional regulation; Caspase-3 mRNA; TLR4; LPS; macrophage activation | ||||
| Dewey Decimal Classification: | 500 Science > 570 Life sciences 600 Technology > 610 Medical sciences Medicine | ||||
| Status: | Published | ||||
| Refereed: | Yes, this version has been refereed | ||||
| Created at the University of Regensburg: | Yes | ||||
| Item ID: | 41996 |
Web of ScienceAbstract
To secure the functionality of activated macrophages in the innate immune response, efficient life span control is required. Recognition of bacterial lipopolysaccharides (LPS) by toll-like receptor 4 (TLR4) induces downstream signaling pathways, which merge to induce the expression of cytokine genes and anti-apoptotic genes. MicroRNAs (miRNAs) have emerged as important inflammatory response ...
Abstract
To secure the functionality of activated macrophages in the innate immune response, efficient life span control is required. Recognition of bacterial lipopolysaccharides (LPS) by toll-like receptor 4 (TLR4) induces downstream signaling pathways, which merge to induce the expression of cytokine genes and anti-apoptotic genes. MicroRNAs (miRNAs) have emerged as important inflammatory response modulators, but information about their functional impact on apoptosis is scarce. To identify miRNAs differentially expressed in response to LPS, cDNA libraries from untreated and LPS-activated murine macrophages were analyzed by deep sequencing and regulated miRNA expression was verified by Northern blotting and qPCR. Employing TargetScan(TM) we identified CASPASE-3 (CASP-3) mRNA that encodes a key player in apoptosis as potential target of LPS-induced miR-155. LPS-dependent primary macrophage activation revealed TLR4-mediated enhancement of miR-155 expression and CASP-3 mRNA reduction. Endogenous CASP-3 and cleaved CASP-3 protein declined in LPS-activated macrophages. Accumulation of miR-155 and CASP-3 mRNA in miRNA-induced silencing complexes (miRISC) was demonstrated by ARGONAUTE 2 (AGO2) immunoprecipitation. Importantly, specific antagomir transfection effectively reduced mature miR-155 and resulted in significantly elevated CASP-3 mRNA levels in activated macrophages. In vitro translation assays demonstrated that the target site in the CASP-3 mRNA 3'UTR mediates miR-155-dependent Luciferase reporter mRNA destabilization. Strikingly, Annexin V staining of macrophages transfected with antagomir-155 and stimulated with LPS prior to staurosporine (SSP) treatment implied that LPS-induced miR-155 prevents apoptosis through CASP-3 mRNA down-regulation. In conclusion, we report that miR-155-mediated CASP-3 mRNA destabilization in LPS-activated RAW 264.7 macrophages suppresses apoptosis, as a prerequisite to maintain their crucial function in inflammation.
Metadata last modified: 17 Mar 2020 11:04
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