Adenovirus binding to cultured synoviocytes triggers signaling through MAPK pathways and induces expression of cyclooxygenase-2.
BACKGROUND
Recombinant adenovirus can be administered in vivo to achieve transduction of a number of cell types including human synoviocytes. Immunogenicity of adenoviruses has limited their utility as vectors for gene delivery; however, specific mechanisms underlying the acute inflammatory response to adenovirus are not well understood. Activation of a number of signal transduction pathways occurs rapidly upon adenovirus binding to cell-surface receptors. We investigated stimulated expression of mitogen-activated protein kinases (MAPKs), cyclooxygenase-2 (COX-2) and prostaglandin E(2) (PGE(2)) in human primary synovial fibroblasts to adenovirus expressing the E. coli beta-galactosidase gene.


METHODS
Cultured rheumatoid synoviocytes were exposed to transduction-competent Ad/RSVlacZ recombinant adenovirus or transduction-incompetent (psoralen/UV-irradiated) Ad/RSVlacZ. The effects on COX-2 expression, PGE(2) levels and MAPK signaling in synoviocytes were assessed using a combination of reverse-transcription polymerase chain reaction amplification and immunoblotting.


RESULTS
Adenovirus treatment of synoviocytes increased levels of COX-2 mRNA and protein as well as PGE(2). Psoralen-treated transcriptionally inactive adenovirus was equivalent to untreated adenovirus for early COX-2 induction suggesting that viral genes were not required. Adenovirus treatment stimulated phosphorylation of ERK-1/-2, p38 MAPK, and JNK. Inhibition of the ERK and p38 MAPK pathways inhibited COX-2 expression and PGE(2) production.


CONCLUSIONS
Taken together, these data demonstrate that a MAPK-dependent increase in COX-2 results in local prostaglandin production. These findings have clinical implications for use of adenovirus as vectors for in vivo gene delivery.
Crofford
Leslie J
LJ
Division of Rheumatology, Department of Internal Medicine, University of Michigan, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA. crofford@umich.edu
McDonagh
Kevin T
KT
Guo
Sutang
S
Mehta
Hemal
H
Bian
Huimin
H
Petruzelli
Lilli M
LM
Roessler
Blake J
BJ
D000256:Adenoviridae / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001172:Arthritis, Rheumatoid / Q000276:immunology / Q000473:pathology; D002478:Cells, Cultured; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000502:physiology*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D013583:Synovial Membrane / Q000166:cytology*; D014161:Transduction, Genetic; D015854:Up-Regulation
D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D020928:Mitogen-Activated Protein Kinases