title: Inhibition of polyadenylation reduces inflammatory gene induction.
abstract: Cordycepin (3' deoxyadenosine) has long been used in the study of in vitro assembled polyadenylation complexes, because it terminates the poly(A) tail and arrests the cleavage complex. It is derived from caterpillar fungi, which are highly prized in Chinese traditional medicine. Here we show that cordycepin specifically inhibits the induction of inflammatory mRNAs by cytokines in human airway smooth muscle cells without affecting the expression of control mRNAs. Cordycepin treatment results in shorter poly(A) tails, and a reduction in the efficiency of mRNA cleavage and transcription termination is observed, indicating that the effects of cordycepin on 3' processing in cells are similar to those described in in vitro reactions. For the CCL2 and CXCL1 mRNAs, the effects of cordycepin are post-transcriptional, with the mRNA disappearing during or immediately after nuclear export. In contrast, although the recruitment of RNA polymerase II to the IL8 promoter is also unaffected, the levels of nascent transcript are reduced, indicating a defect in transcription elongation. We show that a reporter construct with 3' sequences from a histone gene is unaffected by cordycepin, while CXCL1 sequences confer cordycepin sensitivity to the reporter, demonstrating that polyadenylation is indeed required for the effect of cordycepin on gene expression. In addition, treatment with another polyadenyation inhibitor and knockdown of poly(A) polymerase α also specifically reduced the induction of inflammatory mRNAs. These data demonstrate that there are differences in the 3' processing of inflammatory and housekeeping genes and identify polyadenylation as a novel target for anti-inflammatory drugs.
authors.affiliation: School of Pharmacy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kondrashov
authors.forename: Hedda A
authors.initials: HA
authors.lastname: Meijer
authors.forename: Adeline
authors.initials: A
authors.lastname: Barthet-Barateig
authors.forename: Hannah N
authors.initials: HN
authors.lastname: Parker
authors.forename: Asma
authors.initials: A
authors.lastname: Khurshid
authors.forename: Sarah
authors.initials: S
authors.lastname: Tessier
authors.forename: Marie
authors.initials: M
authors.lastname: Sicard
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Knox
authors.forename: Linhua
authors.initials: L
authors.lastname: Pang
authors.forename: Cornelia H
authors.initials: CH
authors.lastname: De Moor
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D002460:Cell Line; D018932:Chemokine CCL2 / Q000235:genetics; D054360:Chemokine CXCL1 / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D003839:Deoxyadenosines / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects*; D006367:HeLa Cells; D006801:Humans; D007249:Inflammation / Q000235:genetics* / Q000378:metabolism / Q000517:prevention & control*; D018836:Inflammation Mediators / Q000037:antagonists & inhibitors / Q000378:metabolism; D016209:Interleukin-8 / Q000235:genetics; D051379:Mice; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D041681:NIH 3T3 Cells; D026723:Polyadenylation / Q000187:drug effects*; D011401:Promoter Regions, Genetic; D020871:RNA Stability / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012132:Respiratory Muscles / Q000187:drug effects / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; C111835:CCL2 protein, human; C475829:CXCL1 protein, human; C508606:CXCL8 protein, human; D018932:Chemokine CCL2; D054360:Chemokine CXCL1; D003839:Deoxyadenosines; D018836:Inflammation Mediators; D016209:Interleukin-8; D016328:NF-kappa B; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D012321:DNA-Directed RNA Polymerases; C058120:cordycepin