title: Small interfering RNAs generated by recombinant dicer induce inflammatory gene expression independent from the TAK1-NFkappaB-MAPK signaling pathways.
abstract: Generation of mixtures of small interfering (si) RNAs by recombinant dicer avoids selection of efficient target sites within mRNAs but little is known about off-target effects of this approach. Using recombinant human dicer we generated siRNA mixtures (dsiRNA) directed against the protein kinase TAK1 and its subunit TAB1, important upstream molecules in the pathways activated by IL-1, TNF, and toll-like receptors (TLR). dsiRNA against TAK1 or TAB1 significantly suppressed their target proteins as well as TAK1-mediated activation of NFkappaB, p38 MAPK, and JNK, and of IL-8 transcription. However, microarray analysis of 136 endogenous inflammatory genes revealed that dsiRNA against TAB1 or TAK1 did not suppress IL-1 or TNF-induced genes but rather induced a broader range of 15 inflammatory genes as well as seven known interferon-response genes. The same genes were induced by dsiRNA directed against luciferase but not by a synthetic control siRNA molecule. Hence, our results show that complex mixtures of siRNA induce an inflammatory gene response that is independent from TAK1-mediated signal transduction. In the light of the increasing usage of enzymatically prepared libraries of siRNA these results provide important insight into potential off-target effects of this approach.
authors.affiliation: Institute of Pharmacology, Medical School Hannover, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Kettner-Buhrow
authors.forename: Oliver
authors.initials: O
authors.lastname: Dittrich-Breiholz
authors.forename: Heike
authors.initials: H
authors.lastname: Schneider
authors.forename: Sabine
authors.initials: S
authors.lastname: Wolter
authors.forename: Klaus
authors.initials: K
authors.lastname: Resch
authors.forename: Michael
authors.initials: M
authors.lastname: Kracht
mesh_terms: D015870:Gene Expression / Q000235:genetics*; D020869:Gene Expression Profiling; D006367:HeLa Cells; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism; D020935:MAP Kinase Signaling System; D016328:NF-kappa B / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D034741:RNA, Small Interfering / Q000235:genetics*; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism*; D000099151:MAP Kinase Kinase Kinase 7
chemical_list: D018836:Inflammation Mediators; D020930:MAP Kinase Kinase Kinases; D016328:NF-kappa B; D034741:RNA, Small Interfering; D043244:Ribonuclease III; D000099151:MAP Kinase Kinase Kinase 7