Shear-induced cyclooxygenase-2 via a JNK2/c-Jun-dependent pathway regulates prostaglandin receptor expression in chondrocytic cells.
Using cDNA microarrays coupled with bioinformatics tools, we elucidated a signaling cascade regulating cyclooxygenase-2 (COX-2), a pivotal pro-inflammatory enzyme expressed in rheumatic and osteoarthritic, but not normal, cartilage. Exposure of T/C-28a2 chondrocytic cells to fluid shear results in co-regulation of c-Jun N-terminal kinase2 (JNK2), c-Jun, and COX-2 as well as concomitant downstream expression of prostaglandin receptors EP2 and EP3a1. JNK2 transcript inhibition abrogated shear-induced COX-2, EP2, and EP3a1 mRNA up-regulation as well as c-Jun phosphorylation. Functional knock-out experiments using an antisense c-Jun oligonucleotide revealed the abolition of shear-induced COX-2, EP2, and EP3a1, but not JNK2, transcripts. Moreover, inhibition of COX-2 activity eliminated mRNA upregulation of EP2 and EP3a1 induced by shear. Hence, a biochemical pathway exists wherein fluid shear activates COX-2, via a JNK2/c-Jun-dependent pathway, which in turn elicits downstream EP2 and EP3a1 mRNA synthesis.
Department of Chemical & Biomolecular Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
James P
JP
Abulencia
Renee
R
Gaspard
Zachary R
ZR
Healy
William A
WA
Gaarde
John
J
Quackenbush
Konstantinos
K
Konstantopoulos
D002460:Cell Line; D019902:Chondrocytes / Q000201:enzymology / Q000378:metabolism*; D051546:Cyclooxygenase 2; D004790:Enzyme Induction; D005786:Gene Expression Regulation; D006801:Humans; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics; D008565:Membrane Proteins; D048056:Mitogen-Activated Protein Kinase 9; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D016376:Oligonucleotides, Antisense / Q000235:genetics; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000235:genetics; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D018078:Receptors, Prostaglandin E / Q000235:genetics*; D058307:Receptors, Prostaglandin E, EP2 Subtype; D058308:Receptors, Prostaglandin E, EP3 Subtype; D012212:Rheology; D015398:Signal Transduction; D014162:Transfection
D007527:Isoenzymes; D008565:Membrane Proteins; D016376:Oligonucleotides, Antisense; C545644:PTGER2 protein, human; C545647:PTGER3 protein, human; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D018078:Receptors, Prostaglandin E; D058307:Receptors, Prostaglandin E, EP2 Subtype; D058308:Receptors, Prostaglandin E, EP3 Subtype; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D048056:Mitogen-Activated Protein Kinase 9; D020928:Mitogen-Activated Protein Kinases