Inducible cyclooxygenase-2 gene expression in the human thyroid epithelial cell line Nthy-ori3-1.
OBJECTIVE
To investigate whether the genes encoding Cyclooxygenase-1 and -2 are expressed in thyroid epithelial cells, in vitro.


METHODS
COX-1/-2 gene expression was examined in the thyroid epithelial cell line Nthy-ori3-1 using semi-quantitative RT-PCR and Western blot analysis. ELISAs were employed to assess whole cell COX-enzyme activity, PGE2 and IL-6 formation.


RESULTS
In response to IL-1beta and TNF-alpha combined cells of the thyroid epithelial cell line Nthy-ori3-1 secreted marked amounts of PGE2 in a time-dependent fashion. This is attributed to increased levels of COX-2 specific mRNA, increased amounts of COX-2 protein and COX enzyme activity in the absence of detectable COX-1 protein. The inhibition of the induced COX enzyme activity by the selective COX-2 inhibitor NS-398 demonstrated the presence of COX-2 pharmacologically. The expression of the COX-2 gene was also accompanied by a marked induction of IL-6 formation, a well described inflammatory response of thyroid epithelial cells.


CONCLUSIONS
Our observation presents first evidence that COX-2 gene expression is inducible in thyroid epithelial cells, in vitro, upon stimulation with the pro-inflammatory cytokines IL-1beta and TNF-alpha. This finding may indicate that thyroid epithelial cells could play an inflammatory controlling role perhaps during auto-immune thyroid diseases.
Berg
J
J
Institute for Laboratory Medicine, General Hospital Linz, Austria. Joerg.Berg@akh.linz.at
Stöcher
M
M
Bogner
S
S
Wölfl
S
S
Pichler
R
R
Stekel
H
H
D015153:Blotting, Western; D002460:Cell Line; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000096:biosynthesis; D004790:Enzyme Induction / Q000187:drug effects; D004847:Epithelial Cells / Q000378:metabolism*; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics; D008565:Membrane Proteins; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D013961:Thyroid Gland / Q000166:cytology / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D007375:Interleukin-1; D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone