Putative cyclooxygenase-3 expression in rat brain cells.
Cyclooxygenase-3 (COX-3), a new acetaminophen-sensitive isoform of the COX family, has recently been cloned from canine tissues. Canine COX-3 apparently is identical to the full-length form of COX-1, with the exception that the COX-3 mRNA retains intron 1. Additionally, COX-3 mRNA expression is high in the brain. We investigated the expression of the putative rat COX-3 mRNA in primary cultures of neurons, astrocytes, endothelial cells, pericytes, and choroidal epithelial cells from the rat brain. Specific RT-PCR primers were designed to detect putative rat COX-3 mRNA, and the RT-PCR products were sequenced and compared to the known sequence of the rat COX-1 gene. Our results demonstrate that the mRNA of the putative COX-3 is expressed in all of the cell types except neurons. Cerebral endothelial cells showed the highest COX-3 expression. Whereas COX-2 expression increased several-fold after lipopolysaccharide (LPS) challenge, COX-1 and COX-3 expression did not change significantly, suggesting that cells constitutively express COX-3. In summary, we report, for the first time to our knowledge, that the putative COX-3 mRNA is detectable in rats and is differentially expressed in various cell types from rat brain, as well as that its expression is not stimulated by LPS.
Department of Physiology and Pharmacology, Wake Forest University, School of Medicine, Winston-Salem, NC 27157, USA. bkis@wfubmc.edu
Bela
B
Kis
James A
JA
Snipes
Toyohi
T
Isse
Krisztina
K
Nagy
David W
DW
Busija
D000818:Animals; D001253:Astrocytes / Q000201:enzymology; D002540:Cerebral Cortex / Q000166:cytology* / Q000201:enzymology; D002829:Choroid / Q000166:cytology / Q000201:enzymology; D004730:Endothelium, Vascular / Q000166:cytology / Q000201:enzymology; D004847:Epithelial Cells / Q000201:enzymology; D005333:Fetus; D009474:Neurons / Q000201:enzymology*; D020286:Pericytes / Q000201:enzymology; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution
D012333:RNA, Messenger; D011451:Prostaglandin-Endoperoxide Synthases; C466421:cyclooxygenase-3